BUILDING A TRACE METALS DATABASE OF CAVE SEDIMENTS OF THE MIDCONTINENT U.S.A

The midcontinent of the United States has thousands of documented caves. Theses caves contain cave sediments, which are the accumulation of biological, geological, and anthropological debris that breaks down over time. Cave sediments have the potential to document the same geologic information stored in speleothems.

As documented by Doughty and Johnson 2012, there is a potential link between trace metal chemistry and cave life. At this time there is no known database for trace metals of cave sediments in Missouri. Considering that caves host a wide variety of life, it is important to create a database of trace metals that can be utilized to examine possible links. Missouri alone has 900 plus species documented in the Missouri cave life database (Elliot, 2007), including several species classified as endangered or threatened by the U.S. Fish and Wildlife Service.

This presentation will report preliminary findings, with a broader study goal of establishing a reference database of trace metals in cave sediments. Samples were analyzed at the University of Arkansas Stable Isotope Lab for analysis by Inductively Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) for the following suite of metals: Ba, Cd, Cu, Cr, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, S, Si, Sr, Ti, and Zn.

Caves were selected using multiple factors which included: urban or rural cave drainage basins, host rock formation age, rock type, and other characteristic. This study is primarily anchored in the Mississippian limestone and Ordovician dolostone of Missouri. However, some samples are being collected from the Mississippian Limestone of Kentucky and the Permian Selenite of Oklahoma to establish a larger baseline database of the midcontinent. This presentation reports the findings of ten caves, three Mississippian aged limestone caves from Missouri, one Mississippian cave from Kentucky, and 6 Cambrian-Ordovician dolostone caves from Missouri. More cave collection and analysis is underway at the present time.