Species Diversity, Distribution, and Abundance, in the Liberty Formation, Brookville, Indiana

Andy Kuss, Hadley Eblen, Eric Shultz

In our research study we were looking at species distribution, diversity, and abundance in a 9m x 9m section of a fossiliferous limestone outcrop of the liberty formation on Rt. 1 south Brookville Indiana. We took a total of 9 samples from a total of three different strata.
The Liberty formation is in the upper Ordovician, a time period when this area was along the equator and was a shallow tropical sea harboring a wide array of marine organisms. As environmental conditions changed due to geologic processes such as uplift, tectonic plate movement, and ice advances and retreats, sea level in this area lowered and rose. This fluctuating shoreline effected marine environments by changing their general position relative to the shoreline. Wave base interaction with the ocean floor affects the types of organisms that are able to survive. More robust and durable organisms may appear above wave base, because they are able to stand the harsher conditions. It is easy to determine whether a sample is above or below wave base, because a sample above wave base will be broken up due to the increased turbidity of the water. If a sample is from below wave base then fossils will be comparatively well preserved. In this study our samples are mainly below wave base, but there is evidence (due to extreme fragmentation of fossils in a few samples) that these fossils were close enough to shore to be effected by storm wave base, which reaches further out to sea than normal wave base, because of increased wave size due to the storm. Because we know that the rocks in this outcrop were all deposited in a marine environment that was relatively unchanged we expect to see diversity through time due to a possible shoreline fluctuation and thus environment change, and relative homogeneity within each strata due to the proximity of the samples in space.
 

Initial Proposal
Experiment process
Data Analysis
Interpretation
Relevance to Class
Conclusion

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