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citpeks
2015-Jun-10, 05:26 PM
If you create an ellipse with axes proportional to the length and width of a Carolina Bay, the ellipse will fit exactly.

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PetersCreek
2015-Jun-10, 09:36 PM
Closed pending clarification.

Clarified: this thread is intended to discuss the geomorphology and geometry of the Carolina Bays and Nebraska rainwater basins. Related discussion about their origins must be consistent with currently accepted mainstream model(s).

grapes
2015-Jun-11, 03:11 AM
If you create an ellipse with axes proportional to the length and width of a Carolina Bay, the ellipse will fit exactly.

20614
Exactly? For tens of thousands of bays? It doesn't even fit exactly the ones in your illustration??

CJSF
2015-Jun-11, 03:22 AM
I don't get the hoopla. They are elliptical, so I would expect them to be ellipses? Are you saying they all have the same proportions? That's not true across the whole breadth of the bays... for example, the ones in north Florida are nearly circular, I believe.

CJSF

Trebuchet
2015-Jun-11, 04:04 AM
So, is there some meaning to this "miraculous" geometry? Aliens? Gods? Or just coincidence? As Grapes points out, not even all of the ones in your picture are anywhere near eliptical.
Lots of geometry occurs naturally. Beehive cells are hexagonal. Planets are spherical, or nearly so. So are soap bubbles. Crystals form lots of lovely geometric shapes. What's your point? Sounds a bit ATM, to me.

citpeks
2015-Jun-11, 04:11 AM
The bays that have well defined margins can be fitted with ellipses. Here is another example from around Fayetteville, NC.

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citpeks
2015-Jun-11, 04:18 AM
So, is there some meaning to this "miraculous" geometry? Aliens? Gods? Or just coincidence? As Grapes points out, not even all of the ones in your picture are anywhere near eliptical.
Lots of geometry occurs naturally. Beehive cells are hexagonal. Planets are spherical, or nearly so. So are soap bubbles. Crystals form lots of lovely geometric shapes. What's your point? Sounds a bit ATM, to me.

I already had my say at an ATM Topic (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays). This is strictly about the morphology. Planets are spherical for a reason, maybe the bays are elliptical for a reason also?

CJSF
2015-Jun-11, 04:19 AM
Yes. Because they are elliptical. So? There are any number of natural processes that can do this. I happen to think water and wind erosion/sediment transport fit best with the evidence. Have you read the research on the bays? I'm not an expert, but I'm at least a little familiar with it, so the fact that some are nearly "perfect" ellipses isn't really a big thing.

CJSF

grapes
2015-Jun-11, 08:53 AM
The bays that have well defined margins can be fitted with ellipses. Here is another example from around Fayetteville, NC.

20621
Even the ones in that picture don't look like they could be fitted "exactly."

Some look more like superellipses than ellipses.

citpeks
2015-Jun-11, 01:07 PM
Even the ones in that picture don't look like they could be fitted "exactly."

Some look more like superellipses than ellipses.

Working only in two dimensions, I am getting the images of the ellipses from Math Open Reference, which has an ellipse that can be adjusted:
http://www.mathopenref.com/coordgeneralellipse.html

NEOWatcher
2015-Jun-11, 02:20 PM
This is strictly about the morphology.
What about it?
I see they are elliptical, but "exactly"? How do you define the exact location of the edges?


I found this image (http://www.scientificpsychic.com/etc/timeline/carolina-bays2.jpg) which is an unmodified section of your picture.

Looking at the craters that you obscured with your shading, we see that the lower (southern) edges of the craters have a gentle slope. How can you determine exactly where that edge lies?


Planets are spherical for a reason, maybe the bays are elliptical for a reason also?
For vastly different reasons.
What shapes would you expect from a crater?

NEOWatcher
2015-Jun-11, 02:21 PM
Working only in two dimensions, I am getting the images of the ellipses from Math Open Reference, which has an ellipse that can be adjusted:
http://www.mathopenref.com/coordgeneralellipse.html
I think most of us on this board know what an ellipse and conic sections are.

mkline55
2015-Jun-11, 03:02 PM
In areas where the bays are relatively unaffected by human activity, are they expanding or shrinking, becoming more round or more oval, more defined or less defined? Are new ones appearing where they did not exist before?

citpeks
2015-Jun-11, 05:24 PM
What about it?
I see they are elliptical, but "exactly"? How do you define the exact location of the edges?

I found this image (http://www.scientificpsychic.com/etc/timeline/carolina-bays2.jpg) which is an unmodified section of your picture.

Looking at the craters that you obscured with your shading, we see that the lower (southern) edges of the craters have a gentle slope. How can you determine exactly where that edge lies?


Determining the edge of a figure, whether done by algorithms or by humans, is always difficult. Determining the borders of the Carolina Bays will have the same problems that are encountered in determining the borders of Moon craters. It would be necessary to use consistent criteria. For the Carolina Bays, I would define the edge as the line just inside the sandy rim. I would not include the sandy rim.



For vastly different reasons.
What shapes would you expect from a crater?

I suppose this is a test question. For an impact crater, the shape would depend on many factors, including the type of target and velocity and composition of the projectile, see for example Melosh 1989. For a volcanic crater, there is a lot of variability. In general, craters have circular shapes, but not always. If you had a crater in the form of tilted cone, the crater edge would be an ellipse. http://en.wikipedia.org/wiki/Ellipse

NEOWatcher
2015-Jun-11, 06:05 PM
For the Carolina Bays, I would define the edge as the line just inside the sandy rim. I would not include the sandy rim.
But you didn't do that. You interpolated the it in some areas.

Let's take your 16x24 ellipse for example.
The rim area to the direct left of the intersection of your axis flows farther into the crater than your circle.
The rim area immediately clockwise from that flow, there is a large flat area level with the floor of the crater that extends past the rim.

So; how can you say "exactly"?





I suppose this is a test question. For an impact crater, the shape would depend on many factors, including the type of target and velocity and composition of the projectile, see for example Melosh 1989. For a volcanic crater, there is a lot of variability. In general, craters have circular shapes, but not always. If you had a crater in the form of tilted cone, the crater edge would be an ellipse. http://en.wikipedia.org/wiki/Ellipse
You don't have to explain conic sections to me. My question is why is this formation worth discussing if an ellipse is a valid shape?

grapes
2015-Jun-11, 06:22 PM
Even the ones in that picture don't look like they could be fitted "exactly."

Some look more like superellipses than ellipses.

Working only in two dimensions, I am getting the images of the ellipses from Math Open Reference, which has an ellipse that can be adjusted:
http://www.mathopenref.com/coordgeneralellipse.html
So, instead of "exact", did you mean "approximately"?

citpeks
2015-Jun-11, 06:35 PM
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But you didn't do that. You interpolated the it in some areas.

Let's take your 16x24 ellipse for example.
The rim area to the direct left of the intersection of your axis flows farther into the crater than your circle.
The rim area immediately clockwise from that flow, there is a large flat area level with the floor of the crater that extends past the rim.

So; how can you say "exactly"?


You have to take into consideration the illumination. The top edge is black, but the bottom edge is lighter in color making it appear to extend further. Is there anything in real life that is "exactly"? All actual measurements have their plus or minus uncertainty.




You don't have to explain conic sections to me. My question is why is this formation worth discussing if an ellipse is a valid shape?

Structures that are 99% elliptical are not encountered frequently in nature. The orbits of the planets, the Carolina Bays, ballistic trajectories, and maybe a few others. I think that the elliptical shape is significant compared to the shape of other terrestrial features such as the Alaskan lakes:
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Grey
2015-Jun-11, 06:43 PM
So, it's clearly true that while not perfect ellipses, the Carolina Bays are pretty close to elliptical. And they're all aligned in pretty much the same direction, with the long axis northwest to southeast. It's a fascinating land formation.

Rather than quibble about how precisely elliptical they are or are not, my question is, what significance are you ascribing to this, citpeks? Why are you bringing it up here?

citpeks
2015-Jun-11, 06:46 PM
In areas where the bays are relatively unaffected by human activity, are they expanding or shrinking, becoming more round or more oval, more defined or less defined? Are new ones appearing where they did not exist before?

Wind and water are mostly eroding the bays rather than crating new ones. In Nebraska, only the largest ones are still visible. Here is a LiDAR image of some bays in Nebraska. Without LiDAR they are almost impossible to see:
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citpeks
2015-Jun-11, 07:16 PM
So, it's clearly true that while not perfect ellipses, the Carolina Bays are pretty close to elliptical. And they're all aligned in pretty much the same direction, with the long axis northwest to southeast. It's a fascinating land formation.

Rather than quibble about how precisely elliptical they are or are not, my question is, what significance are you ascribing to this, citpeks? Why are you bringing it up here?

The reason for my starting this thread in the Geology and Planetary Surfaces section is that the Carolina Bays do not receive much attention in geology courses. Many geologists are not familiar with the regular geometry and alignment of the bays.

My own opinion is that the elliptical structures could have resulted from geological remodeling of oblique conical cavities. However, the mainstream hypothesis is that they were created by wind and water processes because the dates of the terrain span millennia (See for example Brooks 2010). So, I ask myself, how do the wind and water processes create almost perfect ellipses?

==
Brooks, M. J.; B. E. Taylor; and A. H. Ivester, 2010, Carolina bays: time capsules of culture and climate change. Southeastern Archaeology. vol. 29, pp. 146–163

CJSF
2015-Jun-11, 08:26 PM
That's because the bays are not so geological as geomorphological. And there have been extensive studies of the bays and their age, origins and how they might be changing. The orientations seem to correlate with prevailing wind patterns (or reconstructed wind patterns during and just after the last glaciation). Round ponds are actually fairly common - kettle ponds are a good example, though they tend to be smaller than the bays. These features become circular due to erosion and deposition along the shoreline or inner edge - small headlands or lumps are eroded away and any inlets or depressions are filled in, smoothing and circularizing the feature. It's the same process and smooths beaches and bays (proper bays). It's not mysterious or unusual.

Now, I agree, the bays themselves are fascinating. There are theories on how they initially formed, but there is still much to learn about them. The comet fragment hypothesis is not well supported by the current evidence, but you'll still see serious work being done on that front.


the elliptical structures could have resulted from geological remodeling of oblique conical cavities.
??? What does this even mean?

CJSF

Reality Check
2015-Jun-11, 11:40 PM
If you create an ellipse with axes proportional to the length and width of a Carolina Bay, the ellipse will fit exactly.

Given that all of the Carolina Bays are roughly circular or elliptical then of course they are conic sections by definition.
The reason would be that the mechanism of formation created them as roughly circular or elliptical: Carolina Bays: Theories of origin. (http://en.wikipedia.org/wiki/Carolina_Bay#Theories_of_origin)
The wide range of measured ages of the bays suggests that they were not created in one event. So an impact event is not that viable.
The orientation of the bays being consistent with wind patterns suggests a mechanism that created roughly circular depressions that were then sculpted by wind. Maybe currents when the area was under the sea. Movement of ground water can also create circular depressions.

Reality Check
2015-Jun-12, 12:13 AM
So, I ask myself, how do the wind and water processes create almost perfect ellipses?

Why do you ask yourself, citpeks - why do you not ask a geologist or geomorphologist :D? Apparently they are comfortable with various wind and water processes creating almost perfect ellipses (the Bays).

One reasonable scenario:

Carolina is covered with a sea.
The sea drains away - suddenly in some areas.
We know that receding water can create kettles. (http://en.wikipedia.org/wiki/Kettle_(landform)) So it is reasonable to expect Carolina to have roughly circular depressions.
Wind could remodel the rims into approximate eclipses.


Once formed by wind and water processes they could retain their shapes and orientations:
Conference Paper: RAPID SCOUR, SAND RIM CONSTRUCTION, AND BASIN MIGRATION OF A CAROLINA BAY IN SOUTHEASTERN NORTH CAROLINA, Moore et. at. Jun 30, 2014 (http://www.researchgate.net/publication/261177615_RAPID_SCOUR_SAND_RIM_CONSTRUCTION_AND_BA SIN_MIGRATION_OF_A_CAROLINA_BAY_IN_SOUTHEASTERN_NO RTH_CAROLINA)

The fact that these landforms can migrate, yet maintain their characteristic oval shape, orientation, and rim sequences demonstrate that Carolina bays are oriented lakes shaped by lacustrine processes. Clear evidence of basin scour into the underlying Tertiary marine sandy clays reveal that Carolina bay are capable of creating, shaping, and migrating through their own basins while backfilling remnant basins with a regressive sequence of paleoshorelines.
N.B. This conference paper may hint that Bays start as ovals however no date of formation of the bay is stated and the oldest date (32 ka) seems well after the date of Bay formations.

citpeks
2015-Jun-12, 07:55 PM
That's because the bays are not so geological as geomorphological. And there have been extensive studies of the bays and their age, origins and how they might be changing. The orientations seem to correlate with prevailing wind patterns (or reconstructed wind patterns during and just after the last glaciation). Round ponds are actually fairly common - kettle ponds are a good example, though they tend to be smaller than the bays. These features become circular due to erosion and deposition along the shoreline or inner edge - small headlands or lumps are eroded away and any inlets or depressions are filled in, smoothing and circularizing the feature. It's the same process and smooths beaches and bays (proper bays). It's not mysterious or unusual.

Now, I agree, the bays themselves are fascinating. There are theories on how they initially formed, but there is still much to learn about them. The comet fragment hypothesis is not well supported by the current evidence, but you'll still see serious work being done on that front.


the elliptical structures could have resulted from geological remodeling of oblique conical cavities.

??? What does this even mean?

CJSF

The remodeling of oblique conical cavities into shallow ellipses was discussed and illustrated in another thread. (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays&p=2238289#post2238289) I will not discuss it here because it is not mainstream.

citpeks
2015-Jun-12, 08:44 PM
Why do you ask yourself, citpeks - why do you not ask a geologist or geomorphologist :D? Apparently they are comfortable with various wind and water processes creating almost perfect ellipses (the Bays).

One reasonable scenario:

Carolina is covered with a sea.
The sea drains away - suddenly in some areas.
We know that receding water can create kettles. (http://en.wikipedia.org/wiki/Kettle_(landform)) So it is reasonable to expect Carolina to have roughly circular depressions.
Wind could remodel the rims into approximate eclipses.


Once formed by wind and water processes they could retain their shapes and orientations:
Conference Paper: RAPID SCOUR, SAND RIM CONSTRUCTION, AND BASIN MIGRATION OF A CAROLINA BAY IN SOUTHEASTERN NORTH CAROLINA, Moore et. at. Jun 30, 2014 (http://www.researchgate.net/publication/261177615_RAPID_SCOUR_SAND_RIM_CONSTRUCTION_AND_BA SIN_MIGRATION_OF_A_CAROLINA_BAY_IN_SOUTHEASTERN_NO RTH_CAROLINA)

N.B. This conference paper may hint that Bays start as ovals however no date of formation of the bay is stated and the oldest date (32 ka) seems well after the date of Bay formations.

My reason for posting on this forum is not to answer my own question, but to ask the help of geologists or geomorphologists for references to the fluid mechanics calculations or numerical models that show how the elliptical or quasi-elliptical structures of the Carolina Bays are formed.

Thus far, I have not come across a bay formation paper that specifies exactly the motion of the currents, or the motion of the wind, or whatever geological process is needed for the formation of precise ellipses. I don't demand 100% elliptical, I would settle for at least 98% elliptical.

The scenario that you propose is similar to what I have read in many articles. Some depression is altered by water, wind and shifting sand and, voila!, you get elliptical bays. That is a very rough sketch for something that should be very precise.


So it is reasonable to expect Carolina to have roughly circular depressions.
It is reasonable, but I am not satisfied with "roughly".


Wind could remodel the rims into approximate eclipses.
I know that you intended to say ellipses, so I will not dwell on that, but I do not like the word "approximate". I would prefer 98% elliptical, or something like that.

I have many questions, like how are the currents or wind regulated so that they stop when the ellipse shape is achieved? Why doesn't (or didn't) this happen with the kettle lakes in Alaska or Russia? What prevents the wind and water from deforming a perfect ellipse once it has been formed?

All I would like is a reference to a paper that is not wishy-washy with information about prevailing winds or ocean currents. I would like something that has a numerical model that I could plug into my computer and shows me step-by-step how the precisely elliptical bays were formed, and how the overlapping bays managed to retain their elliptical shapes. By the way, the Carolina Bay ellipses are neither too elongated nor too circular. Why do they have a width-to-length ratio around 0.6?

I know that these are hard questions, but a mainstream theory should have the answers.

Swift
2015-Jun-12, 09:39 PM
My reason for posting on this forum is not to answer my own question, but to ask the help of geologists or geomorphologists for references to the fluid mechanics calculations or numerical models that show how the elliptical or quasi-elliptical structures of the Carolina Bays are formed.

You are welcome to ask, but you may have more luck on a geology forum.

NEOWatcher
2015-Jun-12, 09:42 PM
I don't demand 100% elliptical, I would settle for at least 98% elliptical.
[...]
It is reasonable, but I am not satisfied with "roughly".
[...]
but I do not like the word "approximate". I would prefer 98% elliptical, or something like that.
That's what I have a problem with.
I don't agree with your approximations of the shapes.
To illustrate, I took my picture and used them as insets to yours. 1 is unaltered, the other has a rough blue outline of where I see the bottom of the rim of one of the craters.
20640
Even if I strayed a few pixels, it goes nearly 20 pixels off of an ellipse for a 100 pixel wide shape. No where near 98%, exact, perfect or whatever you want to say.
On top of that, you only marked out 3 out of about 10 (depending if you want to count concentric ones).
What about the one to the left of the 31x19 crater? The top of it is quite round while the bottom left is quite flat.


Why do they have a width-to-length ratio around 0.6?
Even among the 3 you marked there is a 10% variation in ratios.

Besides, why would you expect a large deviation in a fairly uniform soil anyway?

I, myself, would love to see some experimental re-creations, or simulations for it too. But; your issue about using the word "roughly" seems unfounded.

citpeks
2015-Jun-13, 12:48 PM
You are welcome to ask, but you may have more luck on a geology forum.

Thanks, I may do that.

citpeks
2015-Jun-13, 01:14 PM
That's what I have a problem with.
I don't agree with your approximations of the shapes.
To illustrate, I took my picture and used them as insets to yours. 1 is unaltered, the other has a rough blue outline of where I see the bottom of the rim of one of the craters.
20640
Even if I strayed a few pixels, it goes nearly 20 pixels off of an ellipse for a 100 pixel wide shape. No where near 98%, exact, perfect or whatever you want to say.
On top of that, you only marked out 3 out of about 10 (depending if you want to count concentric ones).
What about the one to the left of the 31x19 crater? The top of it is quite round while the bottom left is quite flat.


I agree with you that finding the edges of the bays is difficult. My main point is that compared to the Alaskan lakes or the lakes in the Yamal peninsula, the Carolina Bays have remarkably elliptical shapes.



Even among the 3 you marked there is a 10% variation in ratios.

Besides, why would you expect a large deviation in a fairly uniform soil anyway?

I, myself, would love to see some experimental re-creations, or simulations for it too. But; your issue about using the word "roughly" seems unfounded.
[/COLOR]

The variation from the elliptical shape is one thing. This is a curve-fitting matter.

The variation in the ratios of the conic sections is another thing. This is a variation in the angles of the corresponding cones. If the angle of the cone corresponds to sin(θ) = width/length, then we have:
a ratio of 16/24 corresponds to a cone inclined at an angle of 41.8°
a ratio of 22/32 corresponds to a cone inclined at an angle of 43.4°
a ratio of 19/31 corresponds to a cone inclined at an angle of 37.8°

There should be some meaning in that.

grapes
2015-Jun-13, 01:42 PM
So it is reasonable to expect Carolina to have roughly circular depressions.

It is reasonable, but I am not satisfied with "roughly"

But, even the limited amount of examples that you yourself have provided show that the Carolina Bays are only roughly elliptical.


I agree with you that finding the edges of the bays is difficult. My main point is that compared to the Alaskan lakes or the lakes in the Yamal peninsula, the Carolina Bays have remarkably elliptical shapes.



The variation from the elliptical shape is one thing. This is a curve-fitting matter.

The variation in the ratios of the conic sections is another thing. This is a variation in the angles of the corresponding cones. If the angle of the cone corresponds to sin(θ) = width/length, then we have:
a ratio of 16/24 corresponds to a cone inclined at an angle of 41.8°
a ratio of 22/32 corresponds to a cone inclined at an angle of 43.4°
a ratio of 19/31 corresponds to a cone inclined at an angle of 37.8°

There should be some meaning in that.
The calculations you make using width-to-length ratios to calculate the angle of the cone depend upon them being perfect ellipses. That's clearly a false assumption.

NEOWatcher
2015-Jun-13, 03:07 PM
I agree with you that finding the edges of the bays is difficult. My main point is that compared to the Alaskan lakes or the lakes in the Yamal peninsula, the Carolina Bays have remarkably elliptical shapes.
That's my point. It's difficult, therefore any claim of "perfect", "exact", "98%" cannot be made.



The variation in the ratios of the conic sections is another thing. This is a variation in the angles of the corresponding cones.
[...]
There should be some meaning in that.
Yes, it means that not only is the shape only roughly elliptical, but the ellipse shapes vary.
What is the meaning of any patterns in nature?

citpeks
2015-Jun-13, 06:36 PM
But, even the limited amount of examples that you yourself have provided show that the Carolina Bays are only roughly elliptical.

The calculations you make using width-to-length ratios to calculate the angle of the cone depend upon them being perfect ellipses. That's clearly a false assumption.

The orbital calculations from Newtonian mechanics depend on the orbits being perfect ellipses. It is not quite so, is it? Nothing in nature is mathematically perfect. Close enough is sometimes good enough.

Here is an image of a lake in Alaska and a Carolina Bay.
20642

In the following image I overlaid ellipses proportional to the length and the width at the midpoint. Even though you may find imperfections in the fit of the ellipse on the Carolina Bay, a mathematical test such as Least Squares Fitting (http://mathworld.wolfram.com/LeastSquaresFitting.html) could be used to quantify the degree of non-conformance in proportion to the area of the ellipse.

We can see that the Alaska lake has a poor fit with some boundaries inside the ellipse and other boundaries outside of the ellipse. This is clearly not elliptical.

20641

It would clearly be wrong to try mathematical calculations on the Alaska lakes. However, the Carolina Bays are close enough to ellipses that we may learn something by using some mathematical calculations based on their shape.

NEOWatcher
2015-Jun-13, 07:20 PM
The orbital calculations from Newtonian mechanics depend on the orbits being perfect ellipses. It is not quite so, is it?
Orbital calculations as perfect ellipses from Newtonian mechanics rely on 2 bodies. The reason they are not perfect is because there are more bodies influencing the orbits. When you consider the influences in the multiple bodies and take in relativity, they do become mathematically perfect.

These formations are from chaotic processes where many chaotic processes have some order.




Here is an image of a lake in Alaska and a Carolina Bay.
Your attachments aren't working.


It would clearly be wrong to try mathematical calculations on the Alaska lakes. However, the Carolina Bays are close enough to ellipses that we may learn something by using some mathematical calculations based on their shape.
Only those that you are choosing to evaluate are "close enough" in your mind that you think a calculation would work.

What about this one (http://srelherp.uga.edu/SPARC/images/thunderbayaerial.jpg), or these (https://planetrickdotcom.wordpress.com/type/image/page/3/).

The news media picks the most interesting pictures, other non mainstream sites also pick the most interesting ones and the ones that align with their agenda. We are not getting a full picture of the variety and variability. Then you go from that already non-representative set and apply your own selective reasoning.

This is like an analysis of paint spatters. We can determine the direction of the splatter by the shape and orientation of the spots, but there's nothing that can be found by trying to mathematically model the spots themselves.
In this case, the orientation has matched with theories of impacts (shown as not likely) or wind directions.

Squink
2015-Jun-14, 11:48 AM
I suppose Google-earthers have closely examined the circular swath of land between Carolina and Nebraska? There ought to be at least a few of these elliptical features along that path, unless one wants to argue that they're the ends of rays.

Reality Check
2015-Jun-14, 10:27 PM
My reason for posting on this forum is not to answer my own question, but to ask the help of geologists or geomorphologists...snipped lots of nitpicking...

My point remains, citpeks - why have you not asked geologists or geomorphologists for references to your demand for "the fluid mechanics calculations or numerical models that show how the elliptical or quasi-elliptical structures of the Carolina Bays are formed"?
These numerical models though might not exist. If they do not then you need to show that the mainstream scenarios are physically impossible before looking at other scenarios.
It is also fairly hopeful to think that geologists or geomorphologists specializing in the Bays hang out in this forum!



It is reasonable, but I am not satisfied with "roughly".

It is well known physics, citpeks: You have a basin or water. You release the water from the basin. Turbulent flow creates eddies. Eddies are roughly circular and cut out roughly circular depressions in the basin.

arakish
2015-Jul-12, 07:35 PM
My theory on the formation of the Carolina Bays is due to the phenomena from karst topology. What underlies almost all of North Carolina than a huge bed of limestone? During the massive Ice Ages (Icehouse Earth), the massive mounds of ice actually suppressed the land underneath them through subsidence. As you push down on the poles, what happens to the equatorial region? It is forced out, or "squished out", however you wish to view it, through a process similar to isostasy. Since the land in this region was pushed slightly higher due to the polar ice caps, it started forming the "circular" and "elliptical" shape sink holes. However, the ice receded, allowing the land under the ice to begin rising again, as it is doing to this day. The Hudson Bay and Great Lakes areas are still rising due to the rebound of isostasy. Obversely, the region of eastern North Carolina is sinking due to subsidence. This has been proven by sophisticated GPS equipment. I have even participated in one such event here in NC. Over a three year period, the region we measured dropped 2.5mm. As the land subsided, ground water was forced up into the pre-sink holes. Before, the holes could actually sink, more silt and deposits filled-in these holes faster than they could be eroded away like a sink hole and actually become a sink hole.

Thus, you have your Carolina Bays. They are not caused by meteors. No evidence of a meteor has ever been found in any Carolina Bay.

One of my major areas of study was Geology, specifically Geomorphological Deformation. Of course, the above is an over simplified explanation. To fully explain, it would take the 383 pages from one of my text books.

rmfr

citpeks
2015-Jul-13, 12:28 PM
My theory on the formation of the Carolina Bays is due to the phenomena from karst topology. What underlies almost all of North Carolina than a huge bed of limestone? During the massive Ice Ages (Icehouse Earth), the massive mounds of ice actually suppressed the land underneath them through subsidence. As you push down on the poles, what happens to the equatorial region? It is forced out, or "squished out", however you wish to view it, through a process similar to isostasy. Since the land in this region was pushed slightly higher due to the polar ice caps, it started forming the "circular" and "elliptical" shape sink holes. However, the ice receded, allowing the land under the ice to begin rising again, as it is doing to this day. The Hudson Bay and Great Lakes areas are still rising due to the rebound of isostasy. Obversely, the region of eastern North Carolina is sinking due to subsidence. This has been proven by sophisticated GPS equipment. I have even participated in one such event here in NC. Over a three year period, the region we measured dropped 2.5mm. As the land subsided, ground water was forced up into the pre-sink holes. Before, the holes could actually sink, more silt and deposits filled-in these holes faster than they could be eroded away like a sink hole and actually become a sink hole.

Thus, you have your Carolina Bays. They are not caused by meteors. No evidence of a meteor has ever been found in any Carolina Bay.

One of my major areas of study was Geology, specifically Geomorphological Deformation. Of course, the above is an over simplified explanation. To fully explain, it would take the 383 pages from one of my text books.

rmfr

I have no doubt that the Carolina Bays have been subject to a wide range of terrestrial processes. However, I have not encountered a good explanation yet of how the terrestrial processes could have generated such a large number of apparently elliptical features with a narrow range of width-to-length ratios. Such features are not seen in Alaska thermokarst or in the lakes of the Yamal peninsula in Russia. If there were just a few elliptical bays, I could agree that their shape could have arisen by chance through terrestrial processes. However, their radial alignment, which includes the Nebraska rainwater basins, is very peculiar and there is no satisfactory explanation that encompasses the bays in the East Coast and in Nebraska.

Reality Check
2015-Jul-14, 01:32 AM
However, I have not encountered a good explanation yet of how the terrestrial processes could have generated such a large number of apparently elliptical features with a narrow range of width-to-length ratios.
So you have never read the Carolina Bay Wikipedia article (https://en.wikipedia.org/wiki/Carolina_Bay), citpeks :p?

Geomorphology
Various geomorphological hypotheses have been proposed to account for the bays, including action of sea currents when the area was under the ocean or the upwelling of ground water at a later time. One major hypothesis within the earth sciences academic community is that a combination of processes created the shapes and orientations of these ancient landforms, including climate change, the formation of siliciclastic karst by solution of subsurface material during glacial sealevel lowstands and later modification of these depressions by periodic eolian and lacustrine processes.

Quaternary geologists and geomorphologists argue that the peculiar features of Carolina bays can be readily explained by known terrestrial processes and repeated modification by eolian and lacustrine processes of them over the past 70,000 to 100,000 years.[1] Also, Quaternary geologists and geomorphologists believe to have found a correspondence in time between when the active modification of the rims of Carolina bays most commonly occurred and when adjacent sand dunes were active during the Wisconsinan glaciation between 15,000 and 40,000 years (Late Wisconsinan) and 70,000 to 80,000 years BP (Early Wisconsinan).[2] In addition, Quaternary geologists and geomorphologists have repeatedly found that the orientations of the Carolina bays are consistent with the wind patterns which existed during the Wisconsinan glaciation as reconstructed from Pleistocene parabolic dunes, a time when the shape of the Carolina bays was being modified.[3]

Quaternary geologists and geomorphologists have good explanations of how terrestrial processes could have generated such a large number of apparently elliptical features with a narrow range of width-to-length ratios as in the Carolina Bays.
Alaska thermokarst are not Carolina Bays.
The lakes of the Yamal peninsula are not Carolina Bays.
Nebraska rainwater basins are AFAIK not counted as Carolina Bays.

arakish
2015-Jul-14, 01:41 PM
RealityCheck,

Thanks for the Wikipedia link. Even I have never read it. That Geomorphology excerpt is similar to some of the text in my text book for my class. My professor actually loved my hypothesis. Although I said theory above, I should have said hypothesis. My Geomorphology professor even said I could have used that hypothesis to write a dissertation. However, my main focus was into Geographical Information Science and Systems. I only took the Geomorphological Deformation class because the title sounded interesting. The class was also very interesting. I never knew it was going to cover such a broad range.

However, as pointed out by RealityCheck, there are many good explanations of how geomorphological processes could have formed the Carolina Bays the way they did. In the excerpt, it briefly, very briefly, touches on all of the geomorphological processes that could have formed the Carolina Bays.

Also think on this: In which direction is the semi-major axis oriented in all of the Carolina Bays? The same directional orientation of water drainage in eastern North Carolina? Yes, I know, some rivers actually loop around to the opposite direction at times, but the general overall flow of drainage is from the northwest to southeast. The same directional orientation of the semi-major axis of a Carolina Bay.

There are many ways the Carolina Bays could have all been formed. My hypothesis is only one. Perhaps, my hypothesis is just a small part of the overall formation process. Even I do not fully believe my hypothesis. It was just a thought that popped into my head as I thought about the subsidence created by the massive ice sheets and the resulting uplift it would cause elsewhere.

As mentioned in my previous post, since we know for a fact that the land that used to be under the ice sheets is rebounding upward, and the land south of there is subsiding, then logic could be used to show that the opposite is true. With the Carolina region being uplifted and the ocean levels lower, in my opinion only, this would seem that some karst erosion may have been occurring, possibly creating sink holes. However, before the sink holes could truly develop into true sink holes, the climate changed from an Icehouse Earth to a Greenhouse Earth. Thus, the ice caps melted, ocean levels rose which also rose the base level. Since the base level rose, that would mean ground water also rose, filling in those almost sink holes. Know what happens to a pond that does not drain? It fills in with silt, dirt, organic detritus, until the pond actually disappears and becomes land.

As said, my hypothesis may have had a small part in the formation of the Carolina Bays. However, I tend to believe it was the combination of eolian and fluvian processes that simply formed parabolic dunes that later got filled in. Thus, you will have elliptical formations.

Follow the link above to the wiki page. However, use the references links and external links for further research. It might not hurt much to visit the USGS site and some university geology sites.

Of course, to take on your viewpoint, the Carolina Bays could have been formed by a comet that shattered into a shotgun blast. Thus, no evidence of meteors ever found. However, this is unlikely since a comet that shatters would almost also detonate in the atmosphere, much like the Tunguska Event (https://en.wikipedia.org/wiki/Tunguska_event). Remember that Russian meteor just a little while back? Look at how much damage that little thing caused by atmospheric detonation. To this day, I still firmly disbelieve that the Carolina Bays were caused by an impact(s) event. I most firmly believe the geomorphological explanations.

rmfr

Reality Check
2015-Jul-14, 09:28 PM
I think that the range of ages of the Carolina Bays ("predating the end of the Pleistocene by ten of thousands to over a hundred thousand years") is the nail in the coffin of an impact event creating them. It was a reasonable hypothesis 60 years ago before carbon dating and optically stimulated luminescence were used to get these dates.

arakish
2015-Jul-16, 04:34 PM
I think that the range of ages of the Carolina Bays ("predating the end of the Pleistocene by ten of thousands to over a hundred thousand years") is the nail in the coffin of an impact event creating them. It was a reasonable hypothesis 60 years ago before carbon dating and optically stimulated luminescence were used to get these dates.

Exactly.

However, it bugs me to this day wondering if my hypothesis of partial karst topographical erosion had anything to do with their formation. I still wonder. But, I'll never know since my life has taken other directions away from that possibility. Most of my private studies (or self-studies) now take me into astrophysics, celestial mechanics, orbital mechanics, etc., I probably will never try to study Carolina Bays the way I use to when I was a kid back when Tyrannosaurs ruled. :D

I can remember finding a Carolina Bay only about 1100 meters from the home where I first started my scientific studies. I found it to be fascinating. The Carolina Bay I found was actually a pre-sinkhole. At least I think it was. It had a form very similar to a larval Ant-Lions (https://en.wikipedia.org/wiki/Antlion) lair. It was only about 40 meters in diameter and had sunk about 12 meters below the surrounding land, and it had a pool of water about 2 meters deep, and it had an almost perfect conical shape. I would continuously go and study that "pit." Even took my father and mother to see it. Asked, but they had no idea what caused it. Once I got into the Geomorphological Deformation class many years later, it brought back those memories of that Carolina Bay I found and made me begin wondering if partial karst topographical erosion was the cause of the Carolina Bays.

Thus, my hypothesis.

I have since found that a land developer has since "plowed and filled" that Carolina Bay. Shame. It would have been wonderful to continue studying it to see if actually became a sinkhole, later forming into another Carolina Bay.

rmfr

arakish
2015-Jul-16, 04:47 PM
O! Yes, citpeks. ANY ellipsoid is a conic section. That is a geometric proof.

rmfr

citpeks
2015-Jul-17, 03:15 PM
O! Yes, citpeks. ANY ellipsoid is a conic section. That is a geometric proof.

rmfr

It is not enough to just have an ellipse. There are also the constraints of axial orientation and width-to-length ratios. These are essential features of the Carolina Bays.

Image (http://cosmoquest.org/forum/attachment.php?attachmentid=20621&d=1433995794)

Carolina Bays also are located only on unconsolidated soil and they have raised sandy rims.

Gillianren
2015-Jul-17, 04:03 PM
I'm looking at your image, and it's quite clear that things aren't as exact as all that. There are other features in that image that appear to be the same thing (I'm not familiar with this feature) and aren't all that elliptical, and it's obvious to me that your superimposed ellipses do not completely cover the ones you have chosen.

PetersCreek
2015-Jul-17, 07:36 PM
citpeks,

At 283,436 bytes, the larger image you change to busts our image guidelines by a very wide margin so I have converted it to a link. Please see our rules for more details.

grapes
2015-Jul-18, 11:53 AM
It is not enough to just have an ellipse. There are also the constraints of axial orientation and width-to-length ratios. These are essential features of the Carolina Bays.

Image (http://cosmoquest.org/forum/attachment.php?attachmentid=20621&d=1433995794)

Carolina Bays also are located only on unconsolidated soil and they have raised sandy rims.
That's a fascinating image! Where is it, lat/lon?

The whole thing is covered with 'em! Different orientations, and overlapping ones. The smaller ones seem to be more circular.

citpeks
2015-Jul-18, 03:54 PM
I'm looking at your image, and it's quite clear that things aren't as exact as all that. There are other features in that image that appear to be the same thing (I'm not familiar with this feature) and aren't all that elliptical, and it's obvious to me that your superimposed ellipses do not completely cover the ones you have chosen.

I have been fitting the ellipses at the margin between the center of the bays and the raised rims. There may be some deviation between the geological structures and the mathematical curves. The amount of deviation could be quantified by measuring the number of square meters of the actual structure which are inside or outside the ellipse and then dividing that number by the overall area of the ellipse. In general, the fit is very good.

Geological structures are modified by erosion from wind and water, and by distortions caused by ground movements. Some deviation from the theoretical does not invalidate the observation that the Carolina Bays are true ellipses as long as the deviation is not too great. By analogy, we consider the planets to be spherical, but none are truly spherical. Even the shape of the gas giants that have no mountains is distorted by their rotation. Theoretically speaking, planets are spherical and the Carolina Bays are elliptical.

citpeks
2015-Jul-18, 04:07 PM
That's a fascinating image! Where is it, lat/lon?

The whole thing is covered with 'em! Different orientations, and overlapping ones. The smaller ones seem to be more circular.


The image is of the Carolina Bays 37 km southwest of Fayetteville, NC viewed with LiDAR
(Lat. 34.850, Lon. -79.205)

LiDAR has made a big difference of how the Earth can be viewed. Many geological features that are invisible from aerial views become evident with LiDAR.

There is an online LiDAR viewer for the Carolina Bays here:
http://cintos.org/code/100kViewer/index.html

Gillianren
2015-Jul-18, 04:24 PM
I have been fitting the ellipses at the margin between the center of the bays and the raised rims. There may be some deviation between the geological structures and the mathematical curves. The amount of deviation could be quantified by measuring the number of square meters of the actual structure which are inside or outside the ellipse and then dividing that number by the overall area of the ellipse. In general, the fit is very good.

It didn't look it to me. It looked cherry-picked.


Geological structures are modified by erosion from wind and water, and by distortions caused by ground movements. Some deviation from the theoretical does not invalidate the observation that the Carolina Bays are true ellipses as long as the deviation is not too great. By analogy, we consider the planets to be spherical, but none are truly spherical. Even the shape of the gas giants that have no mountains is distorted by their rotation. Theoretically speaking, planets are spherical and the Carolina Bays are elliptical.

Actually, we consider planets to be oblate spheroids, and "round" is a shorthand for people who don't know the term "oblate spheroid."

Reality Check
2015-Jul-19, 11:41 PM
It is not enough to just have an ellipse. There are also the constraints of axial orientation and width-to-length ratios. These are essential features of the Carolina Bays.

citpeks, We know what the features of the Carolina Bays (https://en.wikipedia.org/wiki/Carolina_bay) are:

Carolina bays are elliptical depressions concentrated along the Atlantic seaboard within coastal Delaware, Maryland, New Jersey, North Carolina, South Carolina, Virginia, Georgia, and northcentral Florida (Prouty 1952, Kaczorowski 1977). ...
Carolina bays vary in size from one to several thousand acres. About 500,000 of them are present in the classic area of the Atlantic Coastal Plain, often in groups, with each bay invariably aligned in a northwest-southeast direction.
We do not need repeated images (no matter how interesting :D) to recognize the basic fact that Carolina Bays are elliptical and oriented. That they are not perfect ellipses is also a real world fact - no one expects them to be perfect!

Is that the end of this thread, citpeks - you are repeating basic facts which everyone who reads about the Carolina Bays knows?
Or are you claiming that you being able to draw an eclipse on some bays in some images is significant in some way?

For example you have ellipses on a few of the bays in that LIDAR image. But anyone can see that the ones you ignore include
* bays with multiple rims.
* bays that are not quite oriented with the images you picked.
* overlapping bays that may or may not be elliptical.
* non-elliptical bays , e.g. with one end pointed and another end rounded.
ETA: You have also hidden the features of the bays that you picked with the overlay of a solid ellipse.

A true ellipse would be one that is perfectly elliptical. You draw a ellipse around the feature and that ellipse matches the rim at every point even if the line is infinitesimally thin. You need a rim that is infinitesimally thin!
A "true" ellipse could be a feature that is elliptical within the errors of measurement. For example draw a series of ellipses around the feature so that every ellipse lies within the rim. From that you get a range of elliptical parameters.
A bay with multiple rims could never be a "true" ellipse. A bay with a non-elliptical shape could never be a "true" ellipse.

citpeks
2015-Jul-20, 01:56 PM
citpeks, We know what the features of the Carolina Bays (https://en.wikipedia.org/wiki/Carolina_bay) are:

We do not need repeated images (no matter how interesting :D) to recognize the basic fact that Carolina Bays are elliptical and oriented. That they are not perfect ellipses is also a real world fact - no one expects them to be perfect!

Is that the end of this thread, citpeks - you are repeating basic facts which everyone who reads about the Carolina Bays knows?
Or are you claiming that you being able to draw an eclipse on some bays in some images is significant in some way?

For example you have ellipses on a few of the bays in that LIDAR image. But anyone can see that the ones you ignore include
* bays with multiple rims.
* bays that are not quite oriented with the images you picked.
* overlapping bays that may or may not be elliptical.
* non-elliptical bays , e.g. with one end pointed and another end rounded.
ETA: You have also hidden the features of the bays that you picked with the overlay of a solid ellipse.

A true ellipse would be one that is perfectly elliptical. You draw a ellipse around the feature and that ellipse matches the rim at every point even if the line is infinitesimally thin. You need a rim that is infinitesimally thin!
A "true" ellipse could be a feature that is elliptical within the errors of measurement. For example draw a series of ellipses around the feature so that every ellipse lies within the rim. From that you get a range of elliptical parameters.
A bay with multiple rims could never be a "true" ellipse. A bay with a non-elliptical shape could never be a "true" ellipse.

Sometimes an image is worth more than a thousand words. The large image elicited a surprised reaction from grapes (http://cosmoquest.org/forum/showthread.php?157267-The-Carolina-Bays-are-conic-sections&p=2301133#post2301133), although he had participated in the ATM thread to stop ignoring the Carolina Bays (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays).

I like your suggestion of drawing a series of ellipses to get a range of elliptical parameters. Maybe this is something that can be done when the mapping of the Carolina Bays becomes a community project like the mapping of the craters of the Moon, Mercury, etc.

I still have not found a source that satisfactorily explains the formation of the bays by terrestrial processes. Experts seem to have diverging ideas about how the shapes of the Carolina Bays originated. Prof. Melosh from Purdue University says that the Carolina Bays are aligned with the prevailing wind, whereas Prof. Brooks from the University of South Carolina in Columbia says that the elongation of the Carolina Bays is perpendicular to the wind direction.

Melosh, H.J., 2011, Planetary Surface Processes, Cambridge University Press, p. 462.

"Thawed permafrost expels water and contracts, sagging downward into small ponds that collect more water and enhance melting. Such thaw lakes are common, creating landscapes packed with kilometer-diameter circular to elliptical ponds that are often aligned with the prevailing wind. Such lakes constitute the infamous Carolina Bays, which impact-crater enthusiasts persistently claim to be of impact origin in spite of the complete lack of evidence for impacts."


Brooks, M. J.; B. E. Taylor; and A. H. Ivester, 2010, Carolina bays: time capsules of culture and climate change. Southeastern Archaeology. vol. 29, pp. 146–163.

"The distinctive shape and NW–SE orientation of bays developed through stronger-than-present southwesterly winds blowing over water ponded in shallow depressions (Brooks et al. 2001b; Carver and Brook 1989; Kaczorowski 1977; Thom 1970). The depressions were expanded and oriented by wave erosion, resulting in bay elongation perpendicular to wind direction and the formation of peripheral, downwind sand rims and shorelines on the eastern and southeastern margins, which were the preferred locations for settlement (Brooks et al. 1996a, 1996b)."

NEOWatcher
2015-Jul-20, 05:15 PM
Sometimes an image is worth more than a thousand words. The large image elicited a surprised reaction from grapes (http://cosmoquest.org/forum/showthread.php?157267-The-Carolina-Bays-are-conic-sections&p=2301133#post2301133), although he had participated in the ATM thread to stop ignoring the Carolina Bays (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays).
But that's still only a very small percentage of the population and not necessarily a representative sampling.
And the surprised reaction is about the picture, not about the orientation. Even Grapes said "Different orientations, and overlapping ones. The smaller ones seem to be more circular."


I like your suggestion of drawing a series of ellipses to get a range of elliptical parameters. Maybe this is something that can be done when the mapping of the Carolina Bays becomes a community project like the mapping of the craters of the Moon, Mercury, etc.
How about a first step with you re-drawing your ellipses with a narrow border and not filling in the ellipse to hide the features underneath?


Prof. Melosh from Purdue University says that the Carolina Bays are aligned with the prevailing wind, whereas Prof. Brooks from the University of South Carolina in Columbia says that the elongation of the Carolina Bays is perpendicular to the wind direction.
Alignment does not necessarily specify direction. It very well could be aligned perpendicularly to the wind.
Besides, I find it hard to believe that two experts can be 90 degrees off from the apparent major axis, or 90 degrees off of wind direction.

Squink
2015-Jul-20, 08:18 PM
Craters of the Rio Cuarto (http://www.crateres.com/sky.htm)
also here (http://www.crateres.com/magazines.htm).

Carolina bays look different.

Reality Check
2015-Jul-21, 12:13 AM
Sometimes an image is worth more than a thousand words...

In science a proper analysis of an image is worth more than a million words, citpeks. An improper analysis of an image is not worth the paper it is not written on.

You state you have not found a source that "satisfactorily" explains the formation of the bays by terrestrial processes. And then you list two sources :eek:!
The terrestrial process of thaw lakes: Melosh, H.J., 2011, Planetary Surface Processes, Cambridge University Press, p. 462.
The terrestrial process of wind action on depressions: Brooks, M. J.; B. E. Taylor; and A. H. Ivester, 2010, Carolina bays: time capsules of culture and climate change. Southeastern Archaeology. vol. 29, pp. 146–163.
This unfortunately makes it sound like no science will satisfy you.

ETA: The two authors do seem to contradict each other as how wind direction affects the bays but you have only quoted a couple of sentences. Brooks is talking about past winds. Maybe Melosh's prevailing winds are todays winds.

citpeks
2015-Jul-21, 03:13 PM
...
How about a first step with you re-drawing your ellipses with a narrow border and not filling in the ellipse to hide the features underneath?


I did that in a previous thread (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays&p=2241115#post2241115).

20809

Generally, the bay interiors are featureless planes, but many have drainage channels.

NEOWatcher
2015-Jul-21, 04:08 PM
I did that in a previous thread (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays&p=2241115#post2241115).
Well, that's one.


Generally, the bay interiors are featureless planes, but many have drainage channels.
But the interior is not the point. The point is that you obstructed the features near the edge. For instance, in this picture, the lower left is well outside the rim.

Reality Check
2015-Jul-21, 10:40 PM
Generally, the bay interiors are featureless planes, but many have drainage channels.
The problem is that the bays may have multiple rims and non-elliptical shapes (as in your image). That suggests the possibility of cherry picking bays or a specific rim in a bay to get an elliptical shape. Thus the need to never hide any part of a bay that you are drawing an ellipse on, citpeks.

arakish
2015-Jul-24, 06:12 AM
I have been fitting the ellipses at the margin between the center of the bays and the raised rims. There may be some deviation between the geological structures and the mathematical curves. The amount of deviation could be quantified by measuring the number of square meters of the actual structure which are inside or outside the ellipse and then dividing that number by the overall area of the ellipse. In general, the fit is very good.

Geological structures are modified by erosion from wind and water, and by distortions caused by ground movements. Some deviation from the theoretical does not invalidate the observation that the Carolina Bays are true ellipses as long as the deviation is not too great. By analogy, we consider the planets to be spherical, but none are truly spherical. Even the shape of the gas giants that have no mountains is distorted by their rotation. Theoretically speaking, planets are spherical and the Carolina Bays are elliptical.

What you are doing is trying to fit the ellipsoids to the actual geographical "SUPER" ellipses using Photoshop. Believe me, I tried with PS4. In my second year of Geology courses at NCSU.

It DOES NOT work. You need true GIS/GPS points to find they are NOT true ellipses. They are "SUPER" ellipses. A super concentration of ellipses overlayed upon each other indicative of a "huge" meteor impact. As the splashback happens, many pieces of the Earth's crust would have been propelled upward to fall in a short distance from the impact event.

Do you think the chunks of crustal material falling back may have caused "elliptical" craters as they fell back to Earth?

It can happen.

Think more. I find your arguments fascinating.

rmfr

P.S. - Yes. I am changing my argument from karst topology to the meteor impact. There was a big one off the "current" DelMarVa peninsula. Ever notice the ring like structure of the "Outer Banks"?

arakish
2015-Jul-24, 06:56 AM
Craters of the Rio Cuarto (http://www.crateres.com/sky.htm)
also here (http://www.crateres.com/magazines.htm).

Carolina bays look different.

Yes. They do. As they should.

Two different parts of the same world with two different climatic regions.

If they did not look different on the same globe with wildly different climatic zones, then I would suspect.

rmfr

PetersCreek
2015-Jul-24, 07:24 AM
It would appear we are straying out of the bounds set in post #2:


Clarified: this thread is intended to discuss the geomorphology and geometry of the Carolina Bays and Nebraska rainwater basins. Related discussion about their origins must be consistent with currently accepted mainstream model(s).

grapes
2015-Jul-24, 10:51 AM
Alignment does not necessarily specify direction. It very well could be aligned perpendicularly to the wind.
Besides, I find it hard to believe that two experts can be 90 degrees off from the apparent major axis, or 90 degrees off of wind direction.
Yep. The quote from Melosh's book comes from the last page of the book, in the thermokarst section. No mention of the bays (according to the index) in the eolian section.

Melosh is probably just referring to the same thing that Brooks, Taylor, and Ivestor are, not trying to contradict them.

citpeks
2015-Sep-15, 06:14 PM
I just came across a paper presented at the May 2015 meeting of the GSA. It has a very interesting chart that shows that the axial orientation of the Carolina Bays and the Nebraska Rainwater Basins can be predicted with a single equation that uses a convergence point at Latitude 43.68, Longitude -83.82. The chart is based on analysis of the orientation of 45,000 bays, so it appears fairly robust. Here is the link:
https://gsa.confex.com/gsa/2015NC/webprogram/Paper254858.html

This is slide 27 from the presentation:
20988

John Mendenhall
2015-Sep-15, 07:40 PM
After some hunting I found this:

http://www.researchgate.net/publication/277304567_A_Tale_Of_Two_Craters_Coriolis-Aware_Trajectory_Analysis_CorrelatesTwo_Pleistocen e_Impact_Strewn_Fields_And_Gives_Michigan_A_Thumb

With some beautiful photograps.

EDIT: You'll probably have to click on the "Full Text" button. Eventually it does give up the full paper. Ceretainly a pleasant change from endless paywalls.

arakish
2015-Dec-11, 10:52 AM
It would appear we are straying out of the bounds set in post #2:

And where is this "straying"?

Please explain.

rmfr

arakish
2015-Dec-11, 11:08 AM
That's because the bays are not so geological as geomorphological. And there have been extensive studies of the bays and their age, origins and how they might be changing. The orientations seem to correlate with prevailing wind patterns (or reconstructed wind patterns during and just after the last glaciation).

And where are your links for this information. I found some. How come you cannot list them?

rmfr

arakish
2015-Dec-11, 12:33 PM
I think that the range of ages of the Carolina Bays ("predating the end of the Pleistocene by ten of thousands to over a hundred thousand years") is the nail in the coffin of an impact event creating them.

And where did this idea come from? Where is your data backing this up?

Dating the soils in the Carolina Bays has absolutely NO relevance on WHEN or HOW they were formed. Dating the soils only tells you the date when the soils were first formed and laid down after the formation of the Appalachian Mountains when there was a subduction zone that formed them two billion years ago and the later erosion of them. Even using OSL will not tell you WHEN or HOW they were formed, only how long ago light was shining on the soils. And I still have my doubts about OSL. Even got to try OSL while at a university (y'all ain't privy as to which one). It is still not a PROVEN technology. However, there are far too many established scientists who swear by it.

One must remember that aging something like the Carolina Bays is only determining when the soils were first formed as rock during the initial formation of the Appalachians and the erosion process began that has worn them down some 2400 to 2800 meters. There is nothing currently known to man that can properly determine the age of the Carolina Bays. We can only hypothesize. And most hypotheses (not theories) I have seen to explain the formation of the Carolina Bays as being aeolian, fluvial, and/or karst have failed miserably. There are far too many other formations formed by aeolian, fluvial, and karst influences. AND NONE OF THEM ARE SO PERFECTLY ELLIPTICAL. ONLY impacts with a very low angle can form such. Especially impacts that are not meteorically or cometly ballistic (i.e. - distal ejecta). Investigate it for yourselves. Prove you are scientists and prove the impact hypothesis false. You shall never be able to do so for me and the studies I have had throughout high school, colleges, and universities.

Since I have also served in the military and watched artillery bombardment videos, the only explanation I find viable is by the SECONDARY impacts due to distal ejecta from a primary impactor. Go to youtube and search for artillery bombardment videos, especially ground impacts and not building impacts (cause I ain't gonna do the work for you). Notice how much "distal ejecta" is launched from those impacts. Meteor and comet impacts can also create explosions and distal ejecta.

It seems as if all you supposed "scientists" here require someone to time travel and film the impact and its effects to get the point through your steel reinforced concrete skulls.

There are NO aeolian, fluvial, and/or karst influences in the formation of Carolina Bays. They are much too perfectly elliptical to have been formed by such influences. Aeolian, fluvial, and karst influences produce either an almost perfect circle, or a shape that is extremely ragged and looking like the extremely ragged shapes produced in calderic explosions and formations. All I need say about this is REALLY LOOK at the Alaskan and Siberian puddles formed by melting of ice. NOT ONE HAS AN ALMOST PERFECT ELLIPTICAL SHAPE. They are either circular, or they look like the Lochs of Scotland (my homeland (I am Highlander.)).

For all my life I have always said the Carolina Bays were formed by either a shotgun meteor/comet blast or by the secondary impacts of the debris thrown up (distal ejecta) from the primary impact. And I have had to deal with hardheads like the persons on these forum boards. I have yet to see any "scientist" say anything scientific about this matter on either this thread or the ATM thread.

The only thing I have read by others on these forum boards is bunch of horse hoowhee questions. AND NOT ONE IS BACKED UP WITH ANY KIND OF DATA, OR LINKS TO THAT DATA, AS TO WHERE YOU THOUGHT OF THOSE QUESTIONS.

I am a scientist. Specifically a GIS Field Specialist with studies mainly focused in geology and geomorphology. I have also studied Celestial Mechanics, Orbital Mechanics, and Impact Mechanics (meteors, comets, ballistic bullets). And I say the Carolina Bays were formed by the secondary impacts from the distal ejecta caused by a primary impact on glaciofields that existed during one of the MANY icehouse Earth periods that has existed in the 4.6 billion year history of the Earth. And I will continually be shot down by the many dummies who refuse to believe that chunks of ice impacting on a noncontiguous sandy surface that has been liquefied (soil liquefaction) by seismic waves will leave ABSOLUTELY NO EVIDENCE of the impactor. The impactor simply melts, adding water to the soil, further aiding soil viscous relaxation to fill the hole.

Believe what you want. If you cannot believe the impact theories causing the formation of the Carolina Bays, then so be it. You are blind to the facts that stare you in the face. Dare I say it, blind to the data that literally slaps you across your blind eyes. Thus, I say none of you who replied to this or the ATM thread are scientists. I have been studying the Carolina Bays ALL MY LIFE. There is no other theory that can explain them, excepting the secondary impact theories.

And I have a question for all of you supposed scientists: Which theory to explain the Carolina Bays was first hypothesized? Answer this question and you will have answered the question of the formation of the Carolina Bays.

Of course, this post may get me permanently banished. And I care not. I refuse to visit a forum board of wannabe scientists. Or scientists who have absolutely no idea about geomorphological deformation. Then again, this post may provide you wannabes with some amusement. Have fun.

rmfr

P.S. - I am working on my second dissertation focusing on the Carolina Bays. Thus, I ain't got much free time. In fact, I stole this time to post this post.

Swift
2015-Dec-11, 01:48 PM
<snip>
It seems as if all you supposed "scientists" here require someone to time travel and film the impact and its effects to get the point through your steel reinforced concrete skulls.

...

Believe what you want. If you cannot believe the impact theories causing the formation of the Carolina Bays, then so be it. You are blind to the facts that stare you in the face. Dare I say it, blind to the data that literally slaps you across your blind eyes. Thus, I say none of you who replied to this or the ATM thread are scientists. I have been studying the Carolina Bays ALL MY LIFE. There is no other theory that can explain them, excepting the secondary impact theories.

arakish,

Your insights on this topic are very welcome, but take it down a notch and stop with the name calling and insults.

CJSF
2015-Dec-11, 03:21 PM
arakish,

Is there an online version of your dissertation or a paper derived therof that we can read? Or does it exist in print format one of us can request?

I will add that nowhere does this forum purport to be "full of scientists". Yes, some of our members are scientists in various disciplines (probably including geology, geomorphology, and the like), but on the whole, most of us are interested amateurs (but generally intelligent). We might ask for evidence or clarification, but isn't that what science is about? And as a scientist (with at least one Ph.D?) I would hope you'd welcome the chance to explain.

CJSF

Squink
2015-Dec-12, 08:02 AM
There is no other theory that can explain them, excepting the secondary impact theoriesHaving done science for a long time:
There is always another theory.
Likely we have just not thought of it yet.

Reality Check
2015-Dec-13, 10:32 PM
And where did this idea come from?

The scientists studying Carolina Bays (https://en.wikipedia.org/wiki/Carolina_bay).
No one is claiming that dating the soils says exactly when the bays were created. They give an upper limit, i.e. that the bays were created before the soil was deposited. OSL (optically stimulated luminescence (https://en.wikipedia.org/wiki/Optically_stimulated_luminescence)) is a PROVEN technology. OSL is not the only dating technique that was used to date the bays. But the OSL dating excludes the Younger Dryas impact hypothesis. The range of possible dates for the bays shows that a continuous process created them, not a single impact event.

There are aeolian, fluvial, and/or karst influences in the probable formation of Carolina Bays (https://en.wikipedia.org/wiki/Carolina_bay)

Geomorphology
Various geomorphological hypotheses have been proposed to account for the bays, including action of sea currents when the area was under the ocean or the upwelling of ground water at a later time. One major hypothesis within the earth sciences academic community is that a combination of processes created the shapes and orientations of these ancient landforms, including climate change, the formation of siliciclastic karst by solution of subsurface material during glacial sealevel lowstands and later modification of these depressions by periodic eolian and lacustrine processes.

Quaternary geologists and geomorphologists argue that the peculiar features of Carolina bays can be readily explained by known terrestrial processes and repeated modification by eolian and lacustrine processes of them over the past 70,000 to 100,000 years.[1] Also, Quaternary geologists and geomorphologists believe to have found a correspondence in time between when the active modification of the rims of Carolina bays most commonly occurred and when adjacent sand dunes were active during the Wisconsinan glaciation between 15,000 and 40,000 years (Late Wisconsinan) and 70,000 to 80,000 years BP (Early Wisconsinan).[2] In addition, Quaternary geologists and geomorphologists have repeatedly found that the orientations of the Carolina bays are consistent with the wind patterns which existed during the Wisconsinan glaciation as reconstructed from Pleistocene parabolic dunes, a time when the shape of the Carolina bays was being modified.[3]

CJSF
2015-Dec-14, 03:58 PM
Actually, Reality Check raises an interesting point. Surely if you're doing your second dissertation on the Carolina Bays, you are familiar with the existing literature and what it says? A bibliography/citation list of which a portion is readily available (and some online)?

CJSF

citpeks
2015-Dec-14, 06:23 PM
The Wikipedia article about the Carolina Bays (https://en.wikipedia.org/wiki/Carolina_bay) lists the 2001 article by Zanner and Kuzila noting that the Nebraska Rainwater Basins have similar characteristics and shapes to the Carolina Bays in the East Coast, but the Wikipedia section on geomorphology does not even mention that the axial orientation of the Nebraska Rainwater Basins is almost perpendicular to the axial orientations of the bays on the East Coast and that they, like the Carolina Bays, are also radially aligned toward the Great Lakes region.

None of the three references cited in the geomorphology section provide a precise explanation for the eolian and lacustrine mechanisms that created the elliptical features with width-to-length ratios averaging 0.58 and how such ratios were maintained over the past 70,000 to 100,000 years.

The article by May and Warne (cited as reference 1 (http://eeg.geoscienceworld.org/content/V/3/261.abstract)) proposes that Carolina Bays "initially developed as silica-karst features that were later modified by eolian and, perhaps, ice-push processes, which enhanced their elliptical form. The subsequent Holocene rise in sea level caused ground-water levels in the coastal plain to equilibrate near the present-day land surface. This curtailed geochemical weathering, as well as eolian and ice-related processes. Ground-water saturation partially reversed chemical reactions associated with intensive weathering of clays beneath the bays, masking evidence of the severe leaching that occurred during their initial formation."

The Nebraska Rainwater Basins are at elevations of 400 to 900 meters above sea level on terrain that has not been close to the sea for about 60 million years, but they have the same width-to-length ratios as the Carolina Bays. The arguments for the East Coast bays do not encompass the conditions found in Nebraska.

Wikipedia
Quaternary geologists and geomorphologists argue that the peculiar features of Carolina bays can be readily explained by known terrestrial processes and repeated modification by eolian and lacustrine processes

Quaternary geologists and geomorphologists will continue arguing, but the arguments will not cease until they have a computational model or a different hypothesis that explains the radial orientation and the consistent width-to-length ratios of the ellipses. The piling on of multiple geological processes without quantification amounts to handwaving, which is not enough to support a scientific hypothesis.

CJSF
2015-Dec-14, 06:59 PM
You can't handwave away the problems with an impactor hypothesis either. The question is what hypotheses and theories best explain the current form and placement of the bays. So far the best fit include aeolian and lacustrine effects and seem to exclude an impactor. I see no reason why the radial alignment of the bays cannot be explained by winds. Models of atmospheric circulation during the past ice ages support it, as far as I've read.

CJSF

Reality Check
2015-Dec-14, 08:44 PM
None of the three references cited in the geomorphology section provide a precise explanation for the eolian and lacustrine mechanisms that created the elliptical features with width-to-length ratios averaging 0.58 and how such ratios were maintained over the past 70,000 to 100,000 years.
We cannot really expect a Wikipedia article to have a complete list of all of the literature on a subject :). But the "precise explanation" to an amateur like me looks obvious - the physics of a water and/or a wind pattern acting on depressions created by the various mechanics mentioned. As for the Nebraska Rainwater Basins - they are only mentioned in that one 2001 citation, not the article. But being under sea is not the one and only mechanism in the geomorphology section, citpeks.

ETA: You are ignoring the fact that many of the bays are not elliptical, citpeks, as pointed out in the Stop ignoring the Carolina Bays ATM thread: They are roughly circles and roughly ellipses with various degrees of departures from perfect circles and ellipses. (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays&p=2241851#post2241851)

ETA:


Once formed by wind and water processes they could retain their shapes and orientations:
Conference Paper: RAPID SCOUR, SAND RIM CONSTRUCTION, AND BASIN MIGRATION OF A CAROLINA BAY IN SOUTHEASTERN NORTH CAROLINA, Moore et. at. Jun 30, 2014 (http://www.researchgate.net/publication/261177615_RAPID_SCOUR_SAND_RIM_CONSTRUCTION_AND_BA SIN_MIGRATION_OF_A_CAROLINA_BAY_IN_SOUTHEASTERN_NO RTH_CAROLINA).

citpeks
2017-Jan-24, 09:36 AM
There is a new paper about the geomorphology of the Carolina Bays:
permanent URL: http://dx.doi.org/10.1016/j.geomorph.2017.01.019

The following link will provide free access to the article until March 14, 2017

https://authors.elsevier.com/a/1URHy,3sl3Xil-

grapes
2017-Jan-24, 04:09 PM
There is a new paper about the geomorphology of the Carolina Bays:
permanent URL: http://dx.doi.org/10.1016/j.geomorph.2017.01.019

The following link will provide free access to the article until March 14, 2017

https://authors.elsevier.com/a/1URHy,3sl3Xil-
It'll be interesting to see what kind of comments you get. Good luck!

Reality Check
2017-Jan-24, 08:45 PM
There is a new paper about the geomorphology of the Carolina Bays:
permanent URL: http://dx.doi.org/10.1016/j.geomorph.2017.01.019
The literature suggests that the Carolina Bays were formed over a long period, e.g. there is a wide range of radiocarbon dates. The OSL dating (as you know) rules out the Younger Dryas impact hypothesis. Oddly the author completely ignores this!

The author "fills" some of the bays with ellipses and concludes that they are elliptical. They ignore the fact that the bays have rims that can be indistinct. They cannot say the original overall shape of the bay was elliptical.
They are roughly circles and roughly ellipses with various degrees of departures from perfect circles and ellipses. (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays&p=2241851#post2241851)

So we have a dubious paper:

Denies the dating of the Carolina Bays.
Thinks that rough shapes are ellipses.
Seems to have not studied the extensive literature on crater formation in astronomy (but knows about Ames!).
No academic affiliation.
Their address is Zamora Consulting which seems to be a computer consulting company. This suggests no expertise in geology or astronomy.
A single author paper.
The author cites their own Kindle e-book as if it were scientific literature :eek:!
The images look like the images in your ATM thread from 2014.
They also appear on a web site linked to by Zamora Consulting.

mkline55
2017-Jan-24, 09:06 PM
The literature suggests that the Carolina Bays were formed over a long period, e.g. there is a wide range of radiocarbon dates. The OSL dating (as you know) rules out the Younger Dryas impact hypothesis. Oddly the author completely ignores this!

The author "fills" some of the bays with ellipses and concludes that they are elliptical. They ignore the fact that the bays have rims that can be indistinct. They cannot say the original overall shape of the bay was elliptical.
They are roughly circles and roughly ellipses with various degrees of departures from perfect circles and ellipses. (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays&p=2241851#post2241851)

So we have a dubious paper:

Denies the dating of the Carolina Bays.
Thinks that rough shapes are ellipses.
Seems to have not studied the extensive literature on crater formation in astronomy (but knows about Ames!).
No academic affiliation.
Their address is Zamora Consulting which seems to be a computer consulting company. This suggests no expertise in geology or astronomy.
A single author paper.
The author cites their own Kindle e-book as if it were scientific literature :eek:!
The images look like the images in your ATM thread from 2014.
They also appear on a web site linked to by Zamora Consulting.


Of those statements, only the first carries any weight. All the others are just an opinion. Whose dating are you citing as being the one true and absolutely irrefutable dating methodology?

John Mendenhall
2017-Jan-24, 09:43 PM
There is a new paper about the geomorphology of the Carolina Bays:
permanent URL: http://dx.doi.org/10.1016/j.geomorph.2017.01.019

The following link will provide free access to the article until March 14, 2017

https://authors.elsevier.com/a/1URHy,3sl3Xil-

I haven't been able to get free access.

Reality Check
2017-Jan-24, 10:28 PM
Of those statements, only the first carries any weight. All the others are just an opinion. Whose dating are you citing as being the one true and absolutely irrefutable dating methodology?
All of them.
Read Carolina bay (https://en.wikipedia.org/wiki/Carolina_bay) to see the wide range of dates that are evidence that their formation is before the Younger Dryas and unlikely to be from one event (an impact).

Although some questions about their chronology remain a matter of discussion, a variety of dating techniques constrained the age of the Carolina bays. The consideration of multiple lines of evidence, e.g. radiocarbon dating, optically stimulated luminescence dating, and palynology, indicate that the Carolina Bays predate the start of the Holocene at least by tens of thousands of years to over a hundred thousand years. The range of dates can be interpreted that they were either created episodically over the last tens of thousands of years or were created at time over a hundred thousand years ago and have since been episodically modified.[13][14][15]
...
A new type of extraterrestrial impact hypothesis was proposed as the result of interest by both popular writers and professional geologists in the possibility of a terminal Pleistocene extraterrestrial impacts, including the Younger Dryas impact hypothesis. It said that the Carolina Bays were created by a low density comet exploding above or impacting on the Laurentide ice sheet about 12,900 years ago.[29] However, this idea has been discredited by OSL dating of the rims of the Carolina bays, paleoenvironmental records obtained from cores of Carolina bay sediments, and other research that shows that many of them are as old as, or older than, 60,000 to 140,000 BP.[13][14][15][30][31]
The Holocene (https://en.wikipedia.org/wiki/Holocene) started about 11,700 years before present.
The Younger Dryas (https://en.wikipedia.org/wiki/Younger_Dryas) started c. 12,900.
Thus the evidence is that the bays were formed at least tens of thousands of years before the Younger Dryas (https://en.wikipedia.org/wiki/Younger_Dryas) and maybe 100,000 years before.

These are the facts about the paper and its author:

There is one author.
No academic affiliation (looks like a computer consultant).
No other papers that I can find by the author.
Cites their e-book as a reference.
Incorrectly fits ellipses inside the bays and asserts that makes them ellipses.
Ignores or is unaware of the extensive literature on crater formation in astronomy.
ETA This includes secondary impacts from impact debris as in the debated Younger Dryas impact hypothesis (https://en.wikipedia.org/wiki/Younger_Dryas_impact_hypothesis).
Contains images that appear on a web site and a 2014 ATM thread in this forum.
The experimental model of the title is using a slingshot to fire ice projectiles into a mixture of pottery clay, sand and some water.
There is no attempt to show that this is a physically realistic model. The velocity of the projectiles is obviously wrong (tens of km/hr rather then the hundreds of a ballistic impact).

Those facts make the paper dubious to everyone who knows about science. For example, papers written by an author with no evidence of expertise in a field are much less likely to be valid then papers written by an expert or group of experts.

ETA: There are what non-dubiously authored papers look like:
Chronological evidence fails to support claim of an isochronous widespread layer of cosmic impact indicators dated to 12,800 years ago (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4040610/) by David J. Meltzer,a,1 Vance T. Holliday,b Michael D. Cannon,c and D. Shane Millerd

aDepartment of Anthropology, Southern Methodist University, Dallas, TX, 75275;
bSchool of Anthropology and Department of Geosciences, University of Arizona, Tucson, AZ, 85721;
cSWCA, Environmental Consultants, Inc., Salt Lake City, UT, 84111; and
dSchool of Anthropology, University of Arizona, Tucson, AZ, 85721
and the reply
Reply to Holliday and Boslough et al.: Synchroneity of widespread Bayesian-modeled ages supports Younger Dryas impact hypothesis (http://www.pnas.org/content/112/49/E6723) by James P. Kennetta,1, Douglas J. Kennettb, Brendan J. Culletonb, J. Emili Aura Tortosac, Ted E. Bunchd, Jon M. Erlandsone, John R. Johnsonf, Jesús F. Jordá Pardog, Malcome A. LeCompteh, William C. Mahaneyi, Kenneth Barnett Tankersleyj, James H. Wittked, Wendy S. Wolbachk, and Allen Westl,2


aDepartment of Earth Science and Marine Science Institute, University of California, Santa Barbara, CA 93106;
bDepartment of Anthropology, Pennsylvania State University, University Park, PA 16802;
cDepartment Prehistoria i Arqueologia, Universitat de Valencia, E-46010 Valencia, Spain;
dGeology Program, School of Earth Science and Environmental Sustainability, Northern Arizona University, Flagstaff, AZ 86011;
eMuseum of Natural and Cultural History, University of Oregon, Eugene, OR 97403;
fSanta Barbara Museum of Natural History, Santa Barbara, CA 93105;
gDepartmento de Prehistoria y Arqueología, Facultad de Geografía e Historia, Universidad Nacional de Educación a Distancia, E-28040 Madrid, Spain;
hCenter of Excellence in Remote Sensing Education and Research, Elizabeth City State University, Elizabeth City, NC 27909;
iQuaternary Surveys, Thornhill, ON, Canada L4J 1J4;
jDepartments of Anthropology and Geology, University of Cincinnati, Cincinnati, OH 45221;
kDepartment of Chemistry, DePaul University, Chicago, IL 60614;
lGeoScience Consulting, Dewey, AZ 86327

Roger E. Moore
2017-Jan-28, 02:24 AM
This topic sounded very familiar. I went to my bookshelves and pulled out Frank Edwards' Strange World, originally published in 1964. On the paperback pages 181-182 is "Target: Earth!", a fact-light discussion of the elliptical Carolina Bays (seen also in Georgia and Virginia) "discovered" by a geologist named Dr. F.A. Melton with the University of Oklahoma, and a physicist named Dr. William Schriever of Oklahoma University. They believed, per Frank Edwards, that thousands of years ago a barrage of meteors struck the area and created the bays after flying over the Midwest.

The problem, as I see it, is that meteor craters are circular even if the meteor hits at an angle.

https://www.scientificamerican.com/article/why-are-impact-craters-al/#

Strange World was popular at the height of the UFO, Loch Ness, ESP thing many years ago, when I was a child and dinosaurs roamed the earth. It's baloney but it was fun to read about long ago. I'll go for a geological explanation.

grapes
2017-Jan-29, 12:22 AM
This topic sounded very familiar. I went to my bookshelves and pulled out Frank Edwards' Strange World, originally published in 1964. On the paperback pages 181-182 is "Target: Earth!", a fact-light discussion of the elliptical Carolina Bays (seen also in Georgia and Virginia) "discovered" by a geologist named Dr. F.A. Melton with the University of Oklahoma, and a physicist named Dr. William Schriever of Oklahoma University. They believed, per Frank Edwards, that thousands of years ago a barrage of meteors struck the area and created the bays after flying over the Midwest.

The problem, as I see it, is that meteor craters are circular even if the meteor hits at an angle.

https://www.scientificamerican.com/article/why-are-impact-craters-al/#
From the article: "This behavior may seem at odds with our daily experience of throwing rocks into a sandbox or mud, because in those cases the shape and size of the 'crater' is dominated by the physical dimensions of the rigid impactor. In the case of astronomical impacts, though, the physical shape and direction of approach of the meteorite is insignificant compared with the tremendous kinetic energy that it carries."

So, impacts -> circular, but rocks splashed off, maybe not.

It is true that this theory has been around a long time, and it was investigated, and more or less disproved over the years. Still some hold outs.

citpeks
2018-Jan-28, 05:30 PM
A model for the production of elliptical bays from inclined conical cavities predicts that inverted stratigraphy should be found in the rims of the Carolina Bays (Zamora, 2017). It turns out that some results published six years ago contained evidence of inverted stratigraphy, but the inversion was ignored because it was considered anomalous.

The appendix of the paper (Bunch, et al., 2012), indicates that the rim of a Carolina Bay tested in Blackville, SC showed inverted stratigraphy. In particular, the date at 152 cmbs was 18.54 ± 1.68 ka, and this layer was found between the 183 cmbs layer dated at 12.96 ± 1.19 ka, and another layer with date at 11.5 ± 1.03 ka at 107 cmbs. The appendix indicates that the date at 152 cmbs was excluded because of the large magnitude of the age reversal, i.e., older sediments lying stratigraphically higher than younger sediments. (see page E1905 and SI Appendix, page 5)

The layer at 107 cmbs could be part of a sedimentary layer accreted during the last 12,900 years, the 152 cmbs layer could correspond to material brought out from the depth during the excavation process that created the bay, and the 183 cmbs layer could correspond to the surface of the original terrain 12,900 years ago.

Inverted stratigraphy in the rims of the Carolina Bays is consistent with impact cratering as explained in Melosh (1989, p. 88).

====

Bunch TE, et al. (2012), Very high-temperature impact melt products as evidence for cosmic airbursts and impacts 12,900 years ago.
Proc Natl Acad Sci USA 109(28): E1903–E1912.
http://www.pnas.org/content/109/28/E1903

Melosh, H.J., "Impact Cratering: A Geologic Process", Oxford University Press, 1989.

Zamora A. (2017), A model for the geomorphology of the Carolina Bays,
Geomorphology DOI 10.1016/j.geomorph.2017.01.019
http://dx.doi.org/10.1016/j.geomorph.2017.01.019

Carolina Bay conic sections
https://youtu.be/kHREGRWOdmw

Reality Check
2018-Jan-28, 08:01 PM
...Inverted stratigraphy in the rims of the Carolina Bays is consistent with impact cratering as explained in Melosh (1989, p. 88).
I do not have a copy of Melosh, H.J., "Impact Cratering: A Geologic Process", Oxford University Press, 1989, but this is clearly not a book on geology and the Carolina Bays.
Your conclusion is wrong. An indication of a single rim with inverted stratigraphy cannot overturn the evidence that has debunked the impact hypothesis for the origin of the Carolina Bays. For example their ages (plural!) do not match any known impacts.

Read Carolina bay (https://en.wikipedia.org/wiki/Carolina_bay) to see the wide range of dates that are evidence that their formation is before the Younger Dryas and unlikely to be from one event (an impact).

FYI, this is inverted or reversed stratigraphy (https://en.wikipedia.org/wiki/Reverse_stratigraphy)

Reverse stratigraphy (sometimes known as inverted stratigraphy) is the result of a process whereby one sediment is unearthed by human or natural actions and moved elsewhere, whereby the latest material will be deposited on the bottom of the new sediment, and progressively earlier material will be deposited higher and higher in the stratigraphy. Such events can be triggered by rockslides, tree throws, or other events which cause the strata of a deposit to be flipped or reversed.
What you describe is looks like a single measurement that is not consistent with the surrounding layers, not the inverted stratigraphy that I would expect from an impact (many layers in reverse order).

The appendix (PDF) (http://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1204453109/-/DCSupplemental/Appendix.pdf) states

The two dates at 107 and 183 cmbs were used to generate an age-depth model, excluding the sample at 152 cmbs because of the large magnitude of the age reversal, i.e., older sediments lying stratigraphically higher than younger sediments
That section (Blackville Site. Stratigraphy and the YDB layer in Core #1.) does not state that there is an inverted stratigraphy which geologists would have noticed.
The above quote is on OSL dating - something you have previously stated is wrong!

adamwglass
2018-Apr-14, 08:18 PM
I just came across a paper presented at the May 2015 meeting of the GSA. It has a very interesting chart that shows that the axial orientation of the Carolina Bays and the Nebraska Rainwater Basins can be predicted with a single equation that uses a convergence point at Latitude 43.68, Longitude -83.82. The chart is based on analysis of the orientation of 45,000 bays, so it appears fairly robust. Here is the link:
https://gsa.confex.com/gsa/2015NC/webprogram/Paper254858.html

This is slide 27 from the presentation:
20988

It may be nitpicking, but it is actually a computer algorithm that predicts the location of the bays using only the location of the convergence point and the latitude
and longitude of particular basin or bay. The equation is only one part of the algorithm

adamwglass
2018-Apr-14, 09:08 PM
The literature suggests that the Carolina Bays were formed over a long period, e.g. there is a wide range of radiocarbon dates. The OSL dating (as you know) rules out the Younger Dryas impact hypothesis. Oddly the author completely ignores this!

The author "fills" some of the bays with ellipses and concludes that they are elliptical. They ignore the fact that the bays have rims that can be indistinct. They cannot say the original overall shape of the bay was elliptical.
They are roughly circles and roughly ellipses with various degrees of departures from perfect circles and ellipses. (http://cosmoquest.org/forum/showthread.php?153071-Stop-ignoring-the-Carolina-Bays&p=2241851#post2241851)

So we have a dubious paper:

Denies the dating of the Carolina Bays.
Thinks that rough shapes are ellipses.
Seems to have not studied the extensive literature on crater formation in astronomy (but knows about Ames!).
No academic affiliation.
Their address is Zamora Consulting which seems to be a computer consulting company. This suggests no expertise in geology or astronomy.
A single author paper.
The author cites their own Kindle e-book as if it were scientific literature :eek:!
The images look like the images in your ATM thread from 2014.
They also appear on a web site linked to by Zamora Consulting.


I want to see the look on your face when Zamora's work is accepted as the consensus. Only your first two comments are substantive, the rest are ad hominem. Yes, it is true that Zamora rejects the dating of the Carolina Bays that states they were created by gradualistic processes, but he does so in a thoughtful and plausible way, by suggesting that the dating has measured the dates of the terrain on which the impacts occurred, not the dates of the impact. Do you have a reasoned, substantive argument against this hypothesis?

Any careful and open-minded reader of Zamora's work would be surprised at your assertion that Zamora "thinks that rough shapes are ellipses." Anyone who has viewed the many elliptical bays contained in the Michael Davias's database of LiDAR images of Carolina Bays on cintos.org would be surprised that you think the character of the largest, most well-formed bays as mathematical ellipses is anything other than a physical fact. Zamora has chosen to focus on the elliptical shape of these bays as the key to understanding the formation of all the bays. Michael Davias has chosen to focus on six characteristic shapes of Carolina Bays that he calls "archetypes" as the key to understanding bay formation. These are both perfectly valid lines of inquiry and deserve more respectful analysis than your cursory and mostly ad hominem response.

Swift
2018-Apr-15, 02:36 AM
I want to see the look on your face when Zamora's work is accepted as the consensus. Only your first two comments are substantive, the rest are ad hominem.
adamwglass

First, welcome to CQ.

Second, do not accuse other members of bad behavior, such as ad hominem. If you someone's post is inappropriate, you Report it (black triangle in the lower left of the post with the ! in it), and let the moderation team deal with it.

As it is, I find nothing wrong with Reality Check's post.

Reality Check
2018-Apr-15, 10:49 PM
Only your first two comments are substantive, the rest are ad hominem...
The paper A model for the geomorphology of the Carolina Bays (PDF) (https://cosmictusk.com/wp-content/uploads/zamora-geomorphology-2017.pdf)

Has a single author (that is a fact).
No academic affiliation (that is a fact)
Their address is Zamora Consulting which seems to be a computer consulting company. This suggests no expertise in geology or astronomy (this is a reasonable conclusion).
The author cites their own Kindle e-book as if it were scientific literature! (this is a fact).
The images look like the images in your ATM thread from 2014 (this is a fact).
They also appear on a web site linked to by Zamora Consulting.

The post is a year old so I am no longer sure why the paper hints that the author seems to have not studied the extensive literature on crater formation in astronomy. I may have been thinking of the physics that impacts generally produce circular craters (https://www.scientificamerican.com/article/why-are-impact-craters-al/).
ETA: The paper discusses liquefaction after a calculation of an energy of impact of 1.03 megatons of TNT for a 1 km diameter crater (13 kiloton for a 220 meter crater). So why is this not the vaporization that produces circular craters?

Section 7 is his impact experiments using very low energy impacts (slingshot into clay and sand). A problem is that these types of experiments lead to the misconception of mostly elliptical craters because they appear for most angles. The literature on crater formation in astronomy points this out. The high energy of meteor impacts leads to vaporization of rock and soil. The fireball creates circular craters for most angles of impact.

He uses this incorrect low energy experiment to assert that OSL dating only is wrong because there is no subsurface exposed to light. That looks wrong as his experiment images have comical cavities (his words) that expose what is under the differently colored surface. He may imagine that the impact squeezes soil away from the impact point so that nothing under the surface is exposed but his experiment as designed cannot show that. He needs different colored "soil" at different depths and that the "comical cavities" only expose the first layer.

He is doubly wrong because the OSL dating (https://en.wikipedia.org/wiki/Carolina_bay#Optically_stimulated_luminescence_dat ing) is done on the rims of the bays. In any impact the crater rim is subsurface material freshly exposed to light.


Do you have a reasoned, substantive argument against this hypothesis?
Carolina bay: Age (https://en.wikipedia.org/wiki/Carolina_bay#Age)

Although some questions about their chronology remain a matter of discussion, a variety of dating techniques constrained the age of the Carolina bays. The consideration of multiple lines of evidence, e.g. radiocarbon dating, optically stimulated luminescence dating, and palynology, indicate that the Carolina Bays predate the start of the Holocene at least by tens of thousands of years to over a hundred thousand years. The range of dates can be interpreted that they were either created episodically over the last tens of thousands of years or were created at time over a hundred thousand years ago and have since been episodically modified.[13][14][15]
Multiple lines of evidence for dates are a reasoned, substantive argument that the bays were not created in a single event or before the Younger Dryas.

Grant Hatch
2018-Apr-17, 07:37 PM
Is it possible that the impacts or impactors were of such a nature that the normal "conical" forms were altered by these conditions? Perhaps the impactors were not stony. They were icy (flashing to steam) or liquid or a combination. Or, The impacts were not on uncovered soil, ie their was water or ice above ground level. Or a combination of both scenarios?

Reality Check
2018-Apr-18, 01:23 AM
Is it possible that the impacts or impactors were of such a nature that the normal "conical" forms were altered by these conditions? Perhaps the impactors were not stony. They were icy (flashing to steam) or liquid or a combination. Or, The impacts were not on uncovered soil, ie their was water or ice above ground level. Or a combination of both scenarios?
My understanding is that meteor (rocks) or comet (ice) impacts are so energetic that there is little difference. Delivering the equivalent of an atomic bomb's worth of energy into a small area tends to hide the nature of he projectile. The terrain should influence the size of the crater and the kind of ejecta.

It is the estimate of an "atomic bomb" worth of energy (as in direct impacts) that makes the low energy experiment invalid. However the scenario in the paper is an impact on an ice sheet that blows chunks of ice away for secondary impacts. Secondary impacts should be lower in energy and perhaps lead to mechanical deformation rather than a fireball vaporizing terrain. But:
Carolina bay (https://en.wikipedia.org/wiki/Carolina_bay)

A new type of extraterrestrial impact hypothesis was proposed as the result of interest by both popular writers and professional geologists in the possibility of a terminal Pleistocene extraterrestrial impacts, including the Younger Dryas impact hypothesis. It said that the Carolina Bays were created by a low density comet exploding above or impacting on the Laurentide ice sheet about 12,900 years ago.[29] However, this idea has been discredited by OSL dating of the rims of the Carolina bays, paleoenvironmental records obtained from cores of Carolina bay sediments, and other research that shows that many of them are as old as, or older than, 60,000 to 140,000 BP.[13][14][15][30][31]
This scenario also has the enormous (literally) problem of no evidence of a big original impact crater.