THE SEARCH FOR DIAMONDS IN THE LARAMIE MOUNTAINS OF THE WYOMING ARCHEAN PROVINCE, USA

Casper College undergraduate students investigated the feasibility of finding hidden kimberlite pipes by means of geological mapping, geophysics, and stream sediment sampling. The Precambrian Laramie Mountains of southeastern Wyoming, locally known as the Iron Mountain Kimberlite district, was chosen based on previous work conducted by the Wyoming State Geological Survey (WSGS), geology of the region, and known kimberlite pipes. Data was collected using micro gravimeter - Scintrex CG-5, magnetometer - G-858 MagMapper, and electrical resistivity - SuperSting R8/IP/SP. Target one was chosen while pre-mapping the area and a topographic bowl like depression was identified. Micro gravimeter data was collected on a 56m transect at 8m intervals. Magnetometer data was collected in an area of 122m by 92m running in a 8m parallel array. Electrical resistivity was collected along a 56m transect at 8m intervals. Target two was chosen because the WSGS identified a regional magnetic anomaly and follow-up research was needed. Microgravimeter data was collected on a 56m transect at 8m intervals. Magnetometer data was collected from an area of 122m by 92m running in an 8m parallel array. Electrical resistivity was collected along a 56m transect at 8m intervals. Two drill site locations were selected based on the geophysical results to prove kimberlite is present at depth. Sediment samples were taken along Middle Sybille Creek and yielded a variety of pink to very deep red and purple colored garnets which have been sent in for EPMA (electron probe micro analyses) testing to determine the garnet-spinel compositions. Once complete the geochemical analyses will help determine if either target has a greater potential to be a diamondiferous kimberlite pipe.