Note: Due to the space necessary for music activities in the lower floor and injuries sustained by Penny Boston, adjustments were made in the location of some of the scientific facilities. Microscopes were moved to one end of the workbench in the upper floor to allow Penny to work in greater comfort and without going up and down the stairs so frequently.

Desert varnishes, rinds, and other possible biosignatures - This area exhibits numerous types of visually distinguishable oxide rinds, discolorations, erosion pits, and other potential biomarkers.

Orange and polka dotted sandstones - The most exciting find involves the polka dotted rocks found largely in conjunction with a interbedded harder sandstone facies within the Morrison bentonites. This thin (10-30cm) layer has bright orange rind on flat exposed surfaces. This rind occurs by itself on many rock faces but is also accompanied by an overlay of dark semi-dendritic, to circular dark spots that resemble manganese dendrites or the manganese rich spots that we find in certain arid land caves. There are also dark polka dots on the same sandstones, presumably on younger fracture faces. These features could be consistent with theories advanced in the literature that iron oxide varnish deposition occurs during drier epochs and manganese oxide layers are microbially formed during somewhat wetter intervals. The possibilities for dating the orange oxide layer, the overlying dark putative manganese dendrites and the isolated dark dots on fresh surfaces are unclear. It is possible that 36Cl- dating, 14C, or other radiogenic incorporation may shed some light on relative ages of these various surface colorations. However, all of these techniques suffer from some methodological problems and are difficult to interpret.

Culture specimens have been scraped from all of these types of materials and inoculated into a variety of six manganese media types and six iron media types to see whether any organisms can be enriched from them. The growth times for such chemolithotrophic organisms is typically many weeks to years so results will take a while to manifest. Another followup on this material will be energy dispersive spectroscopy (EDS) to determine the elemental composition of the colorations compared to parent rock. This will be done in conjunction with SEM (scanning electron microscopy) to image any existing organisms and lithified organisms that may be on the surface.

Dark Desert Varnish - In the vicinity of the Hab, there are numerous instances of the typical shiny, blue-black coating common in many desert areas. Primarily this has formed on the red sandstones dotting the outflow plains. However, there is a wide variety of assorted rock types presumably transported from the nearby Henry Mountains. Many chert examples, poorly formed geodes with agatized centers, quartzites, partially metamorphosed sandstones, chlorite pebbles, even micaceous quartzites. A dark quartzite is the only of these rock types that seems to have a desert varnish coating. At least they have dark rinds. The nature of these awaits further confirmation back in our labs on Earth.

Cultures, and SEM specimens were collected from one of these black desert varnish sites and dealt with as above. In prior work on specimens from central New Mexico, we have found a wide variety of living organisms and preserved and silicified colonies of microcolonial fungi, bacteria, and algae on both sandstones and partly silicified rocks of other types.

Tafoni - There are many instances of elaborate, convoluted tafoni-type erosion in white to buffy sandstone layers both within the Morrison Formation and in some spots in the Dakota Sandstone caprocks. Tafoni refers to decementation of sandstones resulting in swiss cheese like holes in surfaces, columns, networks, and often overhangs and cavities in cliffs.

Some of the tafonified regions here seem to be associated with extensive horizontal oyster bed layers. Some are associated with apparently non-fossil bearing sandstones some of which are horizontal but some are in tilted bedding planes. Originally, we speculated that the tafoni pits in horizontal surfaces were the result of subsequent weathering in impression pits of oyster shells that had weathered out. This may be the case for the oyster beds, but obviously not for the other sandstones. Extensive tafoni erosion has occurred in some sandstone cliff faces in the Lith Canyon area. These may or may not be associated with large flooding events. Episodicity of flooding events is not known at present, but there are extensive fluvial deposits of poorly sorted and loosely consolidated deposits at canyon margins. Flow patterns are visible on unconsolidated fines from minor flow events. Large rocks clearly transported by water dot the channels and are testimony to the vigorous nature of at least some flooding events.

Leached Red Sandstones - Dark red sandstone, rounded boulders dot the roadside on the way to Schubert Pass. The notable feature on these are white leached spots with dark lumpy, often with wormlike dark objects adhered to the surface. We have examined these leached areas. Two hypotheses seem reasonable. Possibly the dark objects were deposited in the original sediments of the sandstone. The chemical and/or microbiological action at that time may have leached iron from the surrounding area and concentrated it into the dark areas. Alternatively, based on our observations of leaching in parent rock by the manganese and iron oxidizing bacteria in our caves, it could be a more recent phenomenon. If the former hypothesis is correct, then we would expect to see the dark objects and leached spots throughout the rock material. If the latter hypothesis is correct, the dark accumulations and leached spots should be confined to the outer layers of boulders and other sized rocks. We have not had the opportunity to test this by breaking open a boulder yet. We may try it on EVA tomorrow on Press Day.

Fluorescence tests - The Overnight EVA reported on previously yielded some interesting tidbits of information. The green bentonite clays exhibited weakly fluorescent yellow patches of perhaps a few centimeters in diameter widely scattered. These patches were not visible by sunlight the next morning.

The polka dotted rocks described above showed a narrow band of weak fluorescence at the margins of the dots. We speculate that this may be an advancing front of a chemical or mineral transformation that produces a transient fluorescent state.

The bottoms of the tafoni pits showed weak fluorescence. The leached spots on the red sandstone glowed bluish white, but not really fluorescently.

OPH Continuation Experiments - Steve has completed the OPH testing on 30 different environmental samples. Trend is toward more positives than negatives over all. Additionally, this trend holds across many rock substrate types, geographic location around the area, and altitudinally. Microenvironments of sample acquisition ranged from riparian to high desert. All of the samples that are positive appear to be mixed cultures of algae, several morphologies of bacteria, microfungi, even a few diatoms thrown in. Which specific organisms may be involved in the OPH reaction is unknown at present.

Every stab culture inoculated over the past week is growing somebody: The medium was formulated using material from sample #5 plus small amounts of R2A low carbon medium. Future plans include isolation of individual strains from the primary cultures in the presence of OPH-sensitive compounds in the growth media.