Mud converts to shale and organic material converts to liquid petroleum:
A) when pressure and temperature are decreased by burial under younger sediment.
B) very quickly in the ocean.
C) when pressure and temperature are increased due to burial under younger sediment.
D) in the range of 0 to 30°C.

Question

Quizplus · Accepted Answer

Mud converts to shale and organic material converts to liquid petroleum when pressure and temperature are increased due to burial under younger sediment. This process is called diagenesis and takes place over millions of years. As sediment accumulates on top of older sediment, pressure and temperature gradually increase, causing the buried organic material to break down into liquid petroleum and the mud to harden into shale.

Mud Converts to Shale and Organic Material Converts to Liquid