Essentials of Geology (Fifth Edition)
Essentials of Geology (Fifth Edition)
5th Edition
ISBN: 9780393263398
Author: Stephen Marshak
Publisher: W. W. Norton & Company
Question
Book Icon
Chapter 16, Problem 1RQ
To determine

The difference between porosity and permeability and the examples of substances with high porosity and low permeability.

Expert Solution & Answer
Check Mark

Answer to Problem 1RQ

Porosity depends only in the presence of pores whereas permeability depends upon the interconnections between the pores. Both are expressed in terms of percentages. Some examples of the substances with high porosity and low permeability are mud-stones, shale etc. The substances with high porosity and low permeability are known as aquitards.

Explanation of Solution

Any open space present within the rock sediment or a given volume of rock is known as porosity. The porosity is expressed as a percentage. When the pore spaces are present within a rock during its formation, it is known as primary porosity. The pores spaces here are developed because grains do not grow to fill all the spaces during crystallization or open spaces are not completely filled with cement. When the new pore spaced is produced after the formation of a rock due to fracturing or chemical effect of some fluids passing through the cementing material, it is known as secondary porosity.

When a pore filled with water is surrounded by the solid rock mass, the water cannot flow out. The movement of water from pore to pore is possible only with the interconnections or conduits between them. For the ground water to flow, the conduits must present between the pores. The permeability of a material depends on many factors such as number of available conduits, size of the conduits and straightness of the conduits.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Knowledge Booster
Background pattern image
Recommended textbooks for you
Text book image
Applications and Investigations in Earth Science ...
Earth Science
ISBN:9780134746241
Author:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Publisher:PEARSON
Text book image
Exercises for Weather & Climate (9th Edition)
Earth Science
ISBN:9780134041360
Author:Greg Carbone
Publisher:PEARSON
Text book image
Environmental Science
Earth Science
ISBN:9781260153125
Author:William P Cunningham Prof., Mary Ann Cunningham Professor
Publisher:McGraw-Hill Education
Text book image
Earth Science (15th Edition)
Earth Science
ISBN:9780134543536
Author:Edward J. Tarbuck, Frederick K. Lutgens, Dennis G. Tasa
Publisher:PEARSON
Text book image
Environmental Science (MindTap Course List)
Earth Science
ISBN:9781337569613
Author:G. Tyler Miller, Scott Spoolman
Publisher:Cengage Learning
Text book image
Physical Geology
Earth Science
ISBN:9781259916823
Author:Plummer, Charles C., CARLSON, Diane H., Hammersley, Lisa
Publisher:Mcgraw-hill Education,