Pollen, Spores and Earth History
Name: Kristina Marie
Date: Fall 2012
How would the layers of the earth contaning pollen, spores and shells give us clues about our earth many years ago?
The short answer is that those fossils tell us what organisms were living at those times. Because different organisms prefer different sorts of environments, that tells us what conditions were present then.
Richard E. Barrans Jr., Ph.D., M.Ed.
Department of Physics and Astronomy
University of Wyoming
It really depends on what we are looking for. Depending on what we find, we have to build a theory of what happened or what conditions existed during each layer.
If we are correct that the deeper we go into the layers of earth the farther into our past we are looking - a reasonable assumption since we are looking in places that have a history of layering deposits (and we have additional corroborating evidence), then what substances we find in each layer will tell us what was common during that particular era.
For example, if we find that a layered cliffside has many deep layers containing shells but the upper layers no longer contain shells, only plants and land animal bones, then we can conclude that the area was once under water. If we find that in many different places that we look, there is a particular layer that is rich in pollen but very little or no animal bones, then we might conclude that this was a time in the Earth's past when the dominant living things on Earth were plants. If we find a layer that has an unusual amount of animal bones, then we might conclude that something happened that caused many animals to die in a very short period of time.
Greg (Roberto Gregorius)
Click here to return to the Environmental and Earth Science Archives
Update: November 2011