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)
“Every thing in his composition was little; and he had all the weaknesses of a little mind, without any of the virtues, or even the vices, of a great one.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)
“The creation of a thousand forests is in one acorn, and Egypt, Greece, Rome, Gaul, Britain, America, lie folded in the first man.”
—Ralph Waldo Emerson (1803–1882)
“On fields all drenched with blood he made his record in war, abstained from lawless violence when left on the plantation, and received his freedom in peace with moderation. But he holds in this Republic the position of an alien race among a people impatient of a rival. And in the eyes of some it seems that no valor redeems him, no social advancement nor individual development wipes off the ban which clings to him.”
—Frances Ellen Watkins Harper (1825–1911)