Basin Substation (44.416327N, 108.105625W)
In the Basin Substation area, the PETM occurs with the transition from the Fort Union Fm. to the Willwood Fm., which is defined by the lowest laterally extensive red paleosols.
Uniquely for the Bighorn Basin, PETM strata in this area include a large number of carbonaceous shales and other rocks with >1% organic carbon by weight. These sediments have been shown to preserve organic molecules and organic microfossils far better than the red (oxidized) mudstone paleosols that are typical of the PETM interval elsewhere. As such, we hope to apply new organic geochemical approaches to better constrain the true magnitude and cause of carbon cycle disruptions that coincide with hyperthermal events.
Between July 13 and 17, 2011 two overlapping cores were successfully drilled at Basin Substation. One core (BBCP-BSN11-1A) is 138.4 meters and the second core (BBCP-BSN11-1B) is 138.6 meters long. Both cores were drilled using only municipal water, thus minimizing potential organic contamination. Downhole geophysical logs (magnetic susceptibility, resistivity, density etc) were recovered to about 100 meters depth.
Basin Substation drill site in July, 2011 (photo by E. Denis)