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SUPPLEMENTARY ONLINE INFORMATION (SOM)
In-situ
evidence for continental crust on Early Mars.
V. Sautter
1*
, M.J. Toplis
2
, R.C. Wiens
3
, A. Cousin
2
, C. Fabre
4
, O. Gasnault
2
, S. Maurice
2
, O. Forni
2
, J. Lasue
2
,
A. Ollila
5
, J.C. Bridges
6
, N. Mangold
7
, S. Le Mouélic
7
, M. Fisk
8
, P.
-Y. Meslin
2
, P. Beck
9
, P.
Pinet
2
, L. Le Deit
7
,
W. Rapin
2
, M. Stolper
10
, H. Newsom
11
, D. Dyar
12
, N. Lanza
3
, D. Vaniman
13
, S. Clegg
3
and J.J. Wray
14
1
IMPMC, Muséum d’Histoire Naturelle, Paris, France,
2
IRAP, Toulouse, France,
3
Los Alamos National
Laboratory, Los Alamos, NM, USA,
4
GeoRessources-
Université de Lorraine, Nancy, France,
5
Chevron Energy
Technology Company, Houston, TX, USA,
6
Space Research Centre, Dept. of Physics and Astronomy,
University of Leicester, UK,
7
LPG, Nantes, France,
8
College of Earth, Ocean, and Atmospheric
Sciences, OR,
USA,
9
Institut de Planétologie et d’Astrophysique, Grenoble, France,
10
Caltech, Pasadena, CA, USA
,
11
Institute
of Meteoritics, Albuquerque, NM, USA,
12
Mount Holyoke College, South Hadley, MA, USA,
13
Planetary
Science Institute, Tucson, AZ, U
SA,
14
Georgia Institute of Technology, Atlanta, GA, USA.
*email:vsautter@mnhn.fr
Gale crater, geological context of the rover traverse and samples studied
The Curiosity rover landing site is located at
-4.59° S, 137.44° E).
Fig. S1a
shows a portion
of the THEMIS IR nighttime mosaic of Bradbury Rise. The landing site is marked by a black
cross within the landing ellipse. It is located at a distal portion of the alluvial fan stretching
below Peace Vallis on the northern rim of Gale crater.
Mafic and light
-toned igneous float rocks were initially observed by the Curiosity rover close
to the Bradbury landing site from sol 1 to 55 in the Hummocky plain unit. After
Curiosity
left
the fluvio
-lacustri
ne deposit of Yellow Knife Bay (sol 55
-326), it traversed back across the
hummocky unit
(Fig. S1b
). An increasing number of light
-toned rocks dominated by
feldspars (porphyritic, felsic coarse
-grained, felsic fine
-grained) together with three groups of
mafic rocks were observed along the traverse from sol 326 to sol 550. The mafic rocks are
described in detail in Cousin et al. (2015)
43
and S
autter et al. (2014)
45
. The rocks selected for
the present study are summarized in
Table S1
.
Laser-Induced Breakdown Spectrometer (LIBS) spectra
ChemCam‘s laser
-
induced breakdown spectrometer (LIBS) uses a pulsed laser to ablate
targets up to ≈ 7 m from the rover. The size of the laser interaction varies with distance,
ranging from 350 μm at 1.5 m to 550 μm at 7 m
36
. The light emitted by the ablated plasma
spark is collected by the same telescope used to transmit the laser beam, and is analyzed by
three spectrometers which record the atomic emission spectrum over the ultraviolet (UV:
240.1-
342.2nm), violet (VIO: 382.1
-469.3 nm), and visible to near
-infrared (VNIR: 474.0
-
906.5 nm) ranges
21, 22
. The ChemCam LIBS spectra consist of 6144 channels covering the
above wavelength range in wavelength with typically several hundred emission peaks
covering all of the major elements and many minor and trace elements.
A typical ChemCam LIBS observation involves the analysis of multiple locations on the
target: common geometries for LIBS observations are square grids (e.g. 3×3, 4×4) and
In situ
evidence for continental crust on early Mars
SUPPLEMENTARY INFORMATION
DOI: 10.1038/NGEO2474
NATURE GEOSCIENCE
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© 2015 Macmillan Publishers Limited. All rights reserved
© 2015 Macmillan Publishers Limited. All rights reserved
© 2015 Macmillan Publishers Limited. All rights reserved