Gilmore Hill (44.516327N, 108.645622W)
Gilmore Hill has well-exposed but steep outcrops that have excellent magnetostratigraphic and mammalian biostratigraphic control.
It is one of the most complete sections that spans the Wa-4/Wa-5 biozone boundary (= “Biohorizon B”) which is the largest mammalian turnover in the early Eocene after the PETM.
Recent isotopic sampling of the surface section in the area has established the existence of an isotopic shift that correlates with the H2 hyperthermal event. Retrieving a core record here will allow us to apply the various methods outlined above to pristine sedimentary material to better document the continental effects of non-PETM hyperthermals, further constrain their cause, and compare them to records of the PETM.
From Aug 1-5, 2011 two overlapping cores were successfully drilled at Gilmore Hill. One core (BBCP-GMH11-3A) is 202.4 meters and the second core (BBCP-GMH11-3B) is 66.7 meters long. Both cores were drilled using only muncipal water thus minimizing the risk of downhole organic contamination. Downhole geophysical logs (magnetic susceptibility, resistivity, density etc) were recovered for 89 meters in the first hole and the entire 66 meters of the second hole.
BBCP science team looking over Gilmore Hill outcrops during planning meeting.