Today was a busy day, with morning and afternoon EVAs to investigate local outcrops and take samples. Our goals were not only to collect samples, but also to familiarize our crew with both the procedures for sample collecting and the look of various rock types in the field. The crews on these EVAs were successful. In fact, their day has been filled with geology.

We began this morning with a briefing on geology, using diagrams, maps, and cross-sections. We discussed the formation of the local rock units and the regional setting, and we also discussed rock types and their identification, and tossed about some ideas for overall questions we'd like to answer in the course of our studies here. One idea that was enthusiastically embraced was a search for perched boulders of volcanic (or intrusive) rocks that appear to have been transported into the MDRS area during times of past large volume surface flow. A general desire to explore the area, looking at some sites noted by previous crews and discovering interesting new localities, was expressed by several crew members. This broad approach is certainly consistent with a survey of a new area, with increasing detail coming as time passes.

The morning EVA was to the west of the Hab, working our way over the small observatory hill and then up to the top of the ridge behind (Hab Ridge), where the Dakota Sandstone crops out. We collected samples near the radio, and observed the landscape to the west towards the Skyline Rim and to the east, looking out over the badlands of the Morrison. We returned to the Hab with samples, and plotted GPS coordinates of locations.

The afternoon EVA was to the east or southeast, the objective of which was to reach and climb the hill about 1.5 kilometers SE of the Hab, a hill we named Southeast Hill (although a more imaginative name could replace this one). The goal was to sample the rocks that capped this hill for comparison with those from Hab Ridge, to see if Southeast Hill is capped by an outlier of Dakota Sandstone. The elevation of the top of Southeast Hill suggests this situation. A secondary goal was to extend the view to the east.

The three-member EVA team traveled overland on foot to Southeast Hill, describing rocks and sediments along the way. They climbed the hill, generally from the south, and they reached the top where they took samples. After this they returned to the Hab. The comparison of the samples from these two EVAs will be done tomorrow, using whatever test materials we have on hand.

Two questions for anyone who might be reading this with ideas/information for your hands in the field:

1) What are the cross-bedded sandstones immediately behind the Hab, upon which the observatory is built? A thin sandy member near the top of the Morrison Formation (in the Brushy Basin)? A slump block from the Dakota above? Or something else?

2) Our second EVA team found an interesting deposit as they were descending Southeast Hill, which I'll describe and ask again for any comments from someone back home. In the red shales of the Morrison, on the S-SE side of the hill, they found a small hole -- perhaps 4 inches in diameter -- which led underground in a nearly horizontal fashion. There were signs that water had run out of the hole (although one team member interpreted the pattern in the clay as that left by water running into the hole). And in the area of the hole there were many flakes -- approximately 3 X 4 inches, and 1/2 inch thick. The EVA crew collected a few of these and on analysis at the Hab they were found to be calcite. Comments?