Biology:

Crew Training: The crew were introduced to the main objectives of astrobiology and the methods of searching for extraterrestrial life. The group brainstormed key characteristics of life and outlined how these characteristics could be detected using robotic and human missions.

During the training EVA to mile marker 111 on highway 24 (WGS 84 - UTM Z12S 0516190, 4246688) (NAD27 - CONUS 0516255, 4246484), the crew was introduced to general field biology sampling techniques. Topics covered included quadrats, line transects, randomized sampling, and sterile collection techniques. As a training exercise the crew collected a variety of interesting samples that they will plate on LB agar to learn sterile laboratory techniques for microbiology.

Halophiles: Four samples were collected during the training EVA. Samples were from two gypsum crusts and two gypsum outcrops. Samples will be plated tonight on LB agar with 15% salts. The two forms of gypsum both formed as evaporites and provide two different saline environments that may harbour halophilic microorganisms.

John collecting from a large gypsum crust

Sample OB01: Gypsum crust located on upper plateau at EVA site.
WGS 84 - UTM Z12S 0516335 4246746
NAD27 - CONUS 0516400 4246542

Sample OB02: Gypsum outcrop located on upper plateau at EVA site.
WGS 84 - UTM Z12S 0516336 4246747
NAD27 - CONUS 0516401 4246543

Sample OB03: Gypsum crust located under an overhang of the sandstone layer.
WGS 84 - UTM Z12S 0516272 4246694
NAD27 - CONUS 0516336 4246490

Sample OB04: Gypsum outcrop located in shale layer within the Dakota Sandstone.
WGS 84 - UTM Z12S 0516026 4246711
NAD27 - CONUS 0516091 4246507

A gypsum crust under a small overhang

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Geology:

Today the crew was introduced to the basic processes of the formation of the solar system including the structure and overall chemistry of the terrestrial planets. Principles of magnetic fields, thermal release produced by radioactive decay, and tectonics were discussed, as were the three basic rock classifications (igneous, sedimentary, and metamorphic).

During the training EVA the contact between the Dakota Sandstones, and the Morrison Formation were investigated again in more detail. The outcrop of Dakota sandstones were locally capped by the ‘oyster beds', which host high concentrations of bivalvia fossils. Variations in bivalve species (articulated, and non-articlulated) were noted in different stratigraphic horizons. Some fossil shells were observed to have extremely thick and robust shells, which indicate that the organisms lived in a very high energy and hostile submarine environment, in which they were subject to strong wave and storm influence. These fossils were invariably seen to be broken and dismembered (single shell halves), indicating that they were transported and deposited after death (thanatocenosis), as opposed to being preserved in situ (biocenosis).

Jonathan investigating Dakota Sandstones

The Dakota Sandstones were again seen to unconformably overly a coal unit of approximately 40cm thickness, and alternating fine sandstone / siltstone beds with occasional thin (1 - 5mm) gypsum layers. The occurrences of this evaporate mineral points to an intermittently submerged setting, in which fine clay and silt was deposited, followed by crystallization of gypsum as the saturated water evaporated, and precipitated calcium sulphate.

The crew were asked to collect rock samples representative of the local lithologies and discuss their significance related to the existence of life in the geological record. The entire crew were very engaged in the task, and offered hypotheses as to the paleoenvironments in which the rocks were formed / deposited.

Danielle collecting representative lithologies