Author Question: Which sediment is categorized under cosmogenous sediments? a. Evaporites b. Ooliths c. ... (Read 44 times)

nelaaney · **on:** Aug 22, 2018

Which sediment is categorized under cosmogenous sediments?
a. Evaporites
b. Ooliths
c. Microtektites
d. Manganese nodules

Question 2

What valuable commodity has yet to be commercially mined from ocean sediments?
a. Natural gas
b. Gravel
c. Diatomaceous earth
d. Manganese nodules

Question 3

Sometimes formations on land can shed light on ocean processes. What do the White Cliffs of Dover
in England show?
a. An accumulation of very fine ooze of mixed origin that was pushed above sea level from
plate tectonics.
b. An accumulation of siliceous ooze that has risen above sea level from plate tectonics.
c. A lithified calcareous ooze that was pushed above sea level from plate tectonics.
d. A sheared cliff that formed during sea floor spreading

wilsonbho · **Reply #1 on:** Aug 22, 2018

Answer to Question 1

ANS: C
Microtektites are a type of cosmogenous sediments. They are thought to form from violent impacts of
meteors and asteroids on Earth. The impact melts part of the crust on impact, causing it to splash back
into space. The material melts again as it travels back through the atmosphere before falling back to
Earth. The result is translucent, oblong sediments made of glass particles. Information can be found in
the section Sediments May be Classified by Source.

Answer to Question 2

ANS: D
Manganese nodules have yet to be commercially mined due to their low market value. As techniques
for deep-sea mining become more advance and raw material prices increase, however, the nodules'
concentration of valuable materials will almost certainly be exploited. Information can be found in the
section Marine Sediments Are Economically Important.

Answer to Question 3

ANS: C
The White Cliffs of Dover are an example of the lithification of calcareous ooze. Although formations
like these are formed in the ocean, they are brought above sea level due to normal processes of plate
tectonics. Information can be found in the section Pelagic Sediments Vary in Composition and
Thickness.