One final trial of hand auguring was performed during today’s EVA. Bedrock was again encountered at a very shallow depth. The Summerville Sandstone makes for colorful rock formations, but not a good medium to drill through. While I’m aware of several good hand auguring locations, they are well beyond what we can reach on foot or by ATV and still be conducting a safe EVA. That aside, today was another productive day of collecting and cataloging surface samples in building a geological profile of the area near the Hab.
We climbed to the top of the plateau just west of the Hab and were immediately struck by the tremendous vista before us. Across the plateau, sheer cliffs of Mancos Shale stood in repose and provided a scenic backdrop for the hour or so that we were collecting samples. Several samples of Dakota Sandstone in various states of erosion were collected and documented, as tracing erosional processes has become an important offshoot of the research I’ve been conducting.
Not far from the edge of the plateau, fossilized shell fragments litter the ground surface. No parent rock was immediately visible so after collecting some shell fragments, I set about trying to find the source rock they had eroded from. In a shallow creek channel, I found outcropped the top of the Dakota Sandstone and a contact with the parent rock of the shell fossils. I collected additional samples of both the parent rock, a friable limestone, and the unknown shell species for additional analysis and proper identification back on Earth. Additionally, I documented some circular structures in the Dakota at the contact boundary. I took extensive photographs and collected fragments for additional analysis.