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View Full Version : What Is The Source Of The White Sand On The Beach In Mombasa?



BigDon
2018-Jan-10, 12:40 AM
It was the only time I've ever been on a pure, sugar white beach. Which was interesting due to its reflective qualities.

We had already been deployed to the Indian Ocean for six months, so most of the flightdeck crew felt they were tanned enough not to have to take extraordinary measures to avoid sunburn.

As it turns out, extraordinary measures were what was needed because the list of sunburned woes ran:

Arches of both feet, bottom of the jaw, bottom of the nose and the lower part of the upper eye sockets. Nor was I alone. It seems few people sun bathe hanging upside down.

I thought the arches of the feet was cheating though. The distance, even in flip-flops, seems too short.

Online I couldn't find any sources, and I've been on numerous coral beaches. This was a crystalline substance. I looked at it really closely as I was curious about it.

PetersCreek
2018-Jan-10, 01:02 AM
I found this in Environmental Sensitivity Atlas for Coastal Area of Kenya, March 2006 (http://www.geus.dk/program-areas/nature-environment/international/reports/kensea/kensea_report06_2-uk.htm):


2.5.3 Sandy Beaches and Dunes
Two types of sandy shores are present along the Kenyan coast.

Gentle to steep sandy beaches without protection from a reef. The beach is
often backed by one or a series of wind-blown sand dunes. The sand may
be of terrestrial origin and supplied by the larger rivers (Tana, Sabaki). This
type of beach is found around Sabaki River mouth, and from Ngomeni
through Ungwana Bay to Lamu Island.

Gently sloping beaches sheltered behind a fringing reef are common along
the coast south of Ungwana Bay. The sand is often white calcareous sand of
marine origin (coral sand). Diani Beach and Watamu Beach are typical
examples.

BigDon
2018-Jan-10, 01:10 AM
Okay, so maybe it was more of a parrotfish poop beach, as opposed to a fine ground coral rubble?

It did seem to have quartz-like translucency in a lot of it. Can aragonite do that?

Jeff Root
2018-Jan-10, 03:23 AM
... the coast south of Ungwana Bay.
Ha! I've never been out of North America, but this name jumped
out at me. It is the location of the San Marco launch platform for
Italian/NASA Space launches. No longer in service.

-- Jeff, in Minneapolis

grapes
2018-Jan-10, 10:08 AM
Were the beaches the calcareous ones?

Rivers can carry pure quartz sand a long way:

http://www.destinchamber.com/history-of-destin


The unique sand of the beaches in the Destin area is among the whitest and most homogenous of the world.

Consisting of small quartz particles, this sand came from a process involving the Appalachian Mountains and the Apalachicola River 20,000 years ago. At the end of the last Ice Age when the world temperatures began warming and the ice caps began melting, large volumes of water were carried by the rivers to the world’s oceans. The Apalachicola River, rising in the Appalachians, carried water to the Gulf of Mexico and continues today.

This water carried the quartz particles from the rock that forms the Appalachian Mountains and deposited them in the Gulf of Mexico, just 125 miles to the east of what is now Destin. As the sea level began to rise, these quartz sands eventually formed a new shoreline. The sands today continually replenish and reach as far west as the Pensacola Pass, their final destination.

Sorry for the esoteric scientific reference link. Chambers of commerce always get the science right, right?

Trebuchet
2018-Jan-10, 03:42 PM
The sunburn story reference to arches of the feet reminds me of going to the beach on a cold cloudy day in Oregon. Jeans, jacket, and hat but barefoot because, after all, it was the beach. 2nd degree burns on the tops of my feet, one of my more painful experiences.