Composition and Creation of The Dune Fields
The white to tan sands of the dune fields are almost pure silica. On average, the sand contains 90-95% quartz and 5-10% mixed rock grains.
The particle shapes are nodular and spheroid. they were formed by airflow erosion of rocks that created small fragments that were then carried away by the wind, to be deposited in natural land depressions. Another factor assisting in the formation of the dunes is the abrupt changes of temperature that exist in the desert, which assisted in the breaking up of surface rock into sand grains.
Read more about this topic: Samalayuca Dunes
Famous quotes containing the words composition and, composition, creation and/or fields:
“The naive notion that a mother naturally acquires the complex skills of childrearing simply because she has given birth now seems as absurd to me as enrolling in a nine-month class in composition and imagining that at the end of the course you are now prepared to begin writing War and Peace.”
—Mary Kay Blakely (20th century)
“Modern Western thought will pass into history and be incorporated in it, will have its influence and its place, just as our body will pass into the composition of grass, of sheep, of cutlets, and of men. We do not like that kind of immortality, but what is to be done about it?”
—Alexander Herzen (1812–1870)
“Like witches they flew along rows
Keeping creation at ease;
With a tendril for needle
They sewed up the air with a stem;”
—Theodore Roethke (1908–1963)
“Ah happy hills! ah pleasing shade!
Ah fields beloved in vain!
Where once my careless childhood stray’d,”
—Thomas Gray (1716–1771)