to create maps this was the job of a cartographer
I would say D the Billingsella Corrugata, it IS in the oldest recorded time line, so by theory, it's the oldest (Don't quote me on that, I'm not %100)
The answer is lake hope this helps
Answer:
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.
