Madelyn Percy

Madelyn Percy using an RTK-GPS

Madelyn Percy using an RTK-GPS

I worked with Dr. Charlie Kerans on a Cretaceous rudist bivalve reef complex in Medina County, Texas, studying the rocks themselves as well as their distribution in a locality that has been carved out by Red Bluff Creek. My interest in carbonates has its roots in one of the first geology courses I took, Sedimentary Rocks, so when I was given the opportunity to work with Dr. Kerans, I immediately took it!

Several important conclusions were made based upon the research carried out at Red Bluff Creek: first of all, three major compositional layers were identified in smaller mounds that developed seaward of the primary reef complex. These three layers, a muddy wackestone base, the rudist mounds themselves, and finally an intermound deposit with rudist shell fragments, are found throughout the locality.

In situ caprinid rudist mounds along the banks of Red Bluff Creek, looking north.

In situ caprinid rudist mounds along the banks of Red Bluff Creek, looking north.

The second goal of the research was to determine if there was a correlation between the mound geometry (their height and width) and the orientation of the rudists within the mound. It was found that there is no correlation; however, as one moves basinward (south), the mounds become broader. The importance of this research lies in its implications for hydrocarbon exploration and for the pumping of water in the drought-plagued regions of south-central Texas.

Honors Advisor:

Dr. Charlie Kerans