(1) Bidahochi basalt-lakebed contact
Coring began at 9:00 AM.
The contact between the Bidahochi basalt and lacustrine strata was reached at 58 ft and was marked by a dramaic color change of dark gray basalt to light olive-gray silt and sand (1).
Bidahochi lake sediments (2) consist of bedded peach and gray colored gypsum-bearing largely clastic sediments.some bedding is apparent through the core liner.
The base of the Bidahochi is marked by a quartz pebble gravelly bed with much reworked Chinle maroon siltstone.
Chinle mudstones below the contact (3) consist of orange to maroon sandy mudstones with distinctive more or less spherical "reduction spots". This part of the Chinle is withion the basal Owl Rock Member. The dark gray cores are Bidahochi basalt, and the yellow-olive cores are Bidahochi lake sediments.
Coring was stopped at 100 ft. The hole was reamed out and casing set in place (4), a process that proceed until well after dark.
(2) Composite photograph of Bidahochi lake sediment core before being cut in two
(3) The red cores are the first cores of the Chinle
(4) Setting Casing to 80 feet