Which of the following is not essential in the formation of black shale units?

a. anaerobic bottom water
b. aerobic bottom water
c. little or no coarse detrital sediment
d. high organic productivity in the overlying oxygen rich water
e. A and C

B. Aerobic bottom water

D. High organic productivity in the overlying oxygen rich water

Explanation:

A Shale is a sedimentary rock usually formed from silt and clay-size mineral. There are different colors of Shale. The Black Shale is formed under anaerobic conditions. This means that oxygen is deficient in the water where the Shale forms.

A little amount of organic materials is required for the formation of Black Shale and because Black Shale is formed in an environment lacking oxygen, an oxygen-rich water would not be necessary for its growth. Sediments are necessary in the formation of Black Shale.

the answer is b. apsidal precession