LIPID ANALYSIS OF THE MIDDLE JURASSIC SUNDANCE GROUP, SHELL, WY

The Sundance Group at Red Canyon Ranch outside of Shell, WY is an 80 m stack of epicontinental shales, limestone, and mixed system carbonate-siliciclastic high energy sequences. Despite the abundance of fossils and unique sedimentology, little chemostratigraphic analysis has been conducted on these Middle Jurassic epicontinental deposits. In 2005, meter interval samples were taken and analyzed for stable organic carbon isotopes. The usage of δ¹³C shows a strong C3 plant signature (δ¹³C = -23.8-29.1‰). The evidence of organic carbon found in the previous analysis led to an analysis of the lipid content within these shale units.

In 2006 - 2007, fifty gram sub-samples of the shale samples were ground and tested for the presence of lipids using a 2:1 chloroform:methanol solution. Many of the samples showed the presence of lipids with a yellow color change to the solution. The samples range from transparent to a dark translucent yellow. The limestones and mixed system units were omitted from the lipid analysis because in the original analysis no evidence of organic carbon was found. We expect to determine terrestrial or pelagic input for each of these samples.