What causes the permeability of a sediment deposit to decrease as it is buried deeply and turned into a sedimentary rock?

Expert Answers

An illustration of the letter 'A' in a speech bubbles

The permeability of a sedimentary deposit is due to the small spaces between the particles that make up the deposit. These pores allow water to pass through the deposit.

As the deposits are buried under layers of deposits and the pressure on the layers lying right at the bottom increases, the particles are forced to come closer and the spaces between them decrease. An increase in pressure also leads to several transformations in terms of the physical and chemical properties of the particles. Many chemical reactions start to take place that increase the temperature and lead to a release of minerals that act like cement and help unite the small particulate matter. In many cases biological factors also play a part in the formation of sedimentary rocks.

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Approved by eNotes Editorial