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, creation and/or fields:
“Give a scientist a problem and he will probably provide a solution; historians and sociologists, by contrast, can offer only opinions. Ask a dozen chemists the composition of an organic compound such as methane, and within a short time all twelve will have come up with the same solution of CH4. Ask, however, a dozen economists or sociologists to provide policies to reduce unemployment or the level of crime and twelve widely differing opinions are likely to be offered.”
—Derek Gjertsen, British scientist, author. Science and Philosophy: Past and Present, ch. 3, Penguin (1989)
“As the truest society approaches always nearer to solitude, so the most excellent speech finally falls into Silence. Silence is audible to all men, at all times, and in all places. She is when we hear inwardly, sound when we hear outwardly. Creation has not displaced her, but is her visible framework and foil. All sounds are her servants, and purveyors, proclaiming not only that their mistress is, but is a rare mistress, and earnestly to be sought after.”
—Henry David Thoreau (1817–1862)
“To the Ocean now I fly,
And those happy climes that ly
Where day never shuts his eye,
Up in the broad fields of the sky:”
—John Milton (1608–1674)