Our aim was to investigate the feasibility of carrying out a geological survey under the conditions that would exist during a manned Mars mission. The investigation was carried out on Mars-like terrain using ATVs, GPS tools, geophysical tools, rock hammers, hand lenses and eyesight, which would be available to spacesuited astronauts. We concluded as follows:

The Geology of the Hab Study Area:

We confirmed the following stratigraphic sequences through EVA. The Morrison Formation: The Salt Wash Member consists of brown mudstone, light gray sandstone and coarse sandstone. It is mainly exposed in Candor Chasma, Muddy Creek River. Kimmeridgian (upper Jurassic). The Brushy Basin Member consists of variegated reddish, purple, green mudstone, crossbedded sandstone and conglomerate. It is mainly exposed around the Hab and makes characteristic dome-shaped terrain. Tuffaceous sandstone sometimes contains pisolites (accretionary lapilli). They are about 1 cm in diameter. Tithonian (upper Jurassic).

The Dakota Formation consists of yellowish sandstone and conglomerate. It unconformably overlies the Morrison Formation and is exposed in the ridge behind the Hab and makes flat top landforms. Coastal deposit. Conglomerate contains abundant Gryphaeidae (ancient oyster) fossils. Most of them are the left valves. The right valves are vary rare. An average size of the left valve is 4-6 cm. Generally oyster fossils show muddy environment. These fossil assemblages may be allochthonous. The genus Gryphaea (Gryphaeidae) had a range from late Triassic to lower Cretaceous. According to recent report, Gryphaea newberryi zone is found near the bottom of the overlying the Tununk Shale Member. Cenomanian (middle Cretaceous).

The Mancos Formation: The Tununk Shale Member consists of light gray shale and light gray sandstone. It is exposed in a bottom part of Skyline Rim. Marine deposit. Cenomanian to Turonian (middle Cretaceous). The Ferron Sandstone Member consists of brown gray fine-grained crossbeded sandstone. It is exposed from a cliff to top of Skyline Rim. Marine deposit. Turonian (middle Cretaceous). We collected rosette-textured calcareous nodules (2 to 7 cm in diameter) in front of Skyline Rim. We estimate that they are "Desert Rose" (gypsum) with some associated carbonate or carbonate replacements of gypsum. They are rounded by affection of water flow. They might be allochthonous by transfer from elsewhere.

Conclusion:

• We could prove that basic geological survey while wearing spacesuits was possible.
• Most of participants were depending on the GPS tools and tended to ignore contour lines on a map. We should be aware of not only the horizontal location but also the vertical location and landforms.
• It was difficult and sometimes dangerous to treat a rock hammer or sample bags while wearing spacesuits. Visibility through a helmet windshield is not always good. I think that development of safe and easy sampling tools adapted for use with spacesuits is valuable.

References:

Doelling, H. H. (2002) Interim Geologic Map of the San Rafael Desert 30' x 60' Quadrangle, Emery and Grand Counties, Utah
Clarke, J. (2002) The Regolith Geology of The MDRS Study Area