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Olivier Gobert

Science report of the UV-mineral Project of the CREW 136.

    The aim of this report is to communicate the current advancement of the UV-mineral project. Indeed,
in the progress of this experiment, I have finished to collect sample in the area of the dry lake,
two kilometers at the north of the MDRS. I have also finished analizing these samples with the UV
light (long and short waves). And I have also mapped the samples with ArcGIS. This report will
explain the steps to my current

    The methodology for this project is quiet simple and can stand in five steps. The first step
consists in the analysis of the maps of the region around the Mars Desert Research Station. The
region is delimited by a buffer of ten kilometers around the Hab to fit with the simulation on Mars.
However, this distance can only be reach with the ATV's. That's why an other buffer of three
kilometers around the Hab had been defined for the EVA.
    The second step of the project was to find areas for the collect of mineral samples. The purpose of
the project is to prove the presence of ancient water in the desert thanks to the evaporitic
minerals created by the evaporation of the water. Thus, it's logical to look for the presence of
minerals in the stream bed of dry river or in dry lake. After analyzing the maps of the close region
of the Hab, I found two spots that could fit for the research. The first one is a dry river with a
five-meters wide bed and the second is a dry lake of a hundred-meters. The first is stand at one
kilometer north of the MDRS and the second is stand at two kilometers north of the MDRS.
    The third step of the project was the collect of minerals in these areas. After three EVA's, I had
collected 22 samples. The methodology for the collecting was quiet simple. The aim was to collect
the more samples as possible in the dry lake that seems different. For the dry river, the
methodology was to do a sampling following a transect of the stream bed. And every sample had been
referenced by there GPS coordinates (UTM 27 - 12S).
    The fourth step was standing by night in the laboratory of the Hab. We analyzed the samples with
the UV light with the short and long UV-waves. The methodology was to light the sample and to see if
there was presence or absence of evaporitic minerals. But an unexpected thing occurs with the
samples. Indeed, the problem is the layer of clay at the surface of every stream bed. This problem
is bigger with the dry lake. Moreover, the clay wasn't dry under the first layer. This complicated
the analysis of the minerals. To overcome this problem, I first dehydrated the wet samples with an
oven and after, when the samples were dry, I crushed them to minimize the size of all the particles
in the sample. With this process, the observation could be made easier.
    The fifth step was to put all the samples in a map using the software ArcMap. With the map of the
positive and negative samples, it could be possible to detect a pattern of the presence of
evaporitic minerals in the desert.

    The material that I use for the project is quiet light. For the collecting, I use small zip-lock
bags for the samples, a GPS for the referencing and a pen. I also use a small pliers to break the
first layer of the ground and to take small minerals. For the analysis, by night, of the samples, I
use a UV-light (long and short waves). I also use the oven to dehydrate the samples and a ceramic
bucket for crushing. I use HCl (10%) for carbonates testing too. And I have some minerals I know
that I use in reference for the sample. In the end, I use ESRI's software ArcGIS for the mapping of
the samples.

    The results that I have at this moment are not very good compared with I was expected. With the
current samples, I can identify a pattern with the dry river. The map shows that there is presence
of evaporitic mineral in the middle of the stream bed and not on the edges of the river. This result
fits with the hypothesis. For the dry lake, I could not find a pattern. I have obtained positive
samples in the edges and in the middle of the lake but also negative samples in the middle of the
dry lake. This state of results could be explained by the high presence of clay in the region making
an impermeable layer in the stream bed and in the lake and biased the results.

    For the continuation of the project I have to find other spots to collect minerals. I have already
found a little sandy (with less clay) canyon at 1,2 kilometers north-east of the Hab. I also have
found a river 6-kilometers north of the base that increase in width and could lead to evaporation of
the water. The analyze and the results of those two new spot will be the subject of my next report.
Hope that the results will be promising

Olivier GOBERT, crew Geologist, CREW 136