Walther's Law: The distribution of environments represented by rocks in a vertical stratigraphic column is related to the distribution of those environments laterally.
Walther's Law: The distribution of environments represented by rocks in a vertical stratigraphic column is related to the distribution of those environments laterally.
In this video, instructor discuss the idea that older layers underlie younger layers. However, the age of individual grains can be significantly older than the age of the layer they were deposited in because the grains have to exist before they are deposited. In the special case of layers of volcanic ash, the ages of crystals in the ash might be only slightly older than the age of the layer they are in, which provides excellent opportunities for measuring the absolute ages of sediments.
This video is a portion of a deltaic sedimentation experiment done at UNLV. It was done as part of Dr. Andrew Hanson's Sed/Strat class and shows different phases of deltaic sedimentation, erosion, and sequence stratigraphy. The plans for this flume tank are at http://serc.carleton.edu/NAGTWorkshops/sedimentary/models/desktop_delta.html The plans come from Dr. Thomas Hickson (University of St. Thomas) and Karen Campbell (National Center for Earth Surface Dynamics)