Focus on Sedimentary Environments

Ancient marine carbonate gravels

Caswell Bay, Gower, South Wales, UK

zoom out
thin section PPL
enlarged image
A detail of image 5: one of the coarser beds in thin section, in plane-polarized light. The section is the correct way up. The base of the unit runs from the upper left down towards the right. Scale bar is in mm.


Look closely at the coarser grains. What are their optical properties, and their shapes? What does this indicate about their origin?


We now have information on the bases of the coarse beds, their internal structure, and the composition of the material within them.

Try to interpret the most likely origin of these coarse beds, which occur intermittently within the Caswell Bay Oolite. Think first about processes and conditions, then about environment.

Page © ; last updated 13 August, 2002