|Varves: Dating Sedimentary Strata|
This lesson discusses the clear evidence of geological events over many millions of years. Students count the number of varves (annual layers of sediment) in shale billets, taken from the Green River Formation in Wyoming. The count is then extended to reflect the entire 260 meters of sediments where the billets originated, a period of approximately 2 million years. This provides a tangible experience for a sense of time, from both a human perspective (vast period) and a geological perspective (very short period).
Intended for grade levels:
Type of resource:
No specific technical requirements, just a browser required
Cost / Copyright:
Copyright 1999 ENSI (Evolution and the Nature of Science Institutes). This material may be copied only for noncommercial classroom teaching purposes, and only if this source is clearly cited.
DLESE Catalog ID: DLESE-000-000-004-785
Resource contact / Creator / Publisher:
Author: John Banister-Marx
Contributor: Larry Flammer
Evolution and the Nature of Science Institutes