Science News
from research organizations

What do lentils have to do with geology?

Date:
January 26, 2016
Source:
Geological Society of America
Summary:
When clayey materials are compressed and sheared, they commonly develop a 'scaly fabric' wherein the clay is divided by braided shear surfaces into lentil-shaped chips. Although such scaly fabrics are found at the bed of glaciers, the base of landslides, and in gougey faults, little is known about how they form or how they deform. Researchers have now used dry lentils to help explore this process.
Share:
FULL STORY

When clayey materials are compressed and sheared, they commonly develop a "scaly fabric" wherein the clay is divided by braided shear surfaces into lentil-shaped chips. Although such scaly fabrics are found at the bed of glaciers, the base of landslides, and in gougey faults, little is known about how they form or how they deform.

In their article for Geology, Matthew Tarling and Christina Rowe use dry lentils to help explore this process.

Tarling and Rowe built a shear box with a sliding floor and filled it with lentils. In a series of experiments, they show that the lentils have a tendency to shift constantly against one another when the bulk is shearing, prohibiting the development of long-lasting faults.

Each lentil follows a slightly different path, at different speeds, to accomplish the broad deformation of the whole. This "delocalization" behavior seems to be intrinsic to the system. This observation suggests an explanation for why scaly layers of clay may grow so broad in faults, landslides, and the beds of glaciers, and why these types of shear networks do not grow into localized fault zones.


Story Source:

The above post is reprinted from materials provided by Geological Society of America. Note: Content may be edited for style and length.


Journal Reference:

  1. Matthew S. Tarling, Christie D. Rowe. Experimental slip distribution in lentils as an analog for scaly clay fabrics. Geology, 2016; G37306.1 DOI: 10.1130/G37306.1

Cite This Page:

Geological Society of America. "What do lentils have to do with geology?." ScienceDaily. ScienceDaily, 26 January 2016. <www.sciencedaily.com/releases/2016/01/160126162229.htm>.
Geological Society of America. (2016, January 26). What do lentils have to do with geology?. ScienceDaily. Retrieved August 24, 2016 from www.sciencedaily.com/releases/2016/01/160126162229.htm
Geological Society of America. "What do lentils have to do with geology?." ScienceDaily. www.sciencedaily.com/releases/2016/01/160126162229.htm (accessed August 24, 2016).