Salar Grande

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Salar Grande
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Typical Salar Morphology
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Outcrop of Salt in Alluvial Mat. Range Formation
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Morphology

• Outcrops
• Sedimentary in Pampa Nevada and volcanic in the
  reddish unit few hundred meters away from the
  landing site (below, looking southwest from
  landing site)

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Morphology Residual Sedimentary Butte
Pampa Nevada Unique limestone occurrence in the
area (oppostite site of landing site, looking
south)
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Morphology General

• General hardness of surface varies from soft
  material in alluvial fan, although consolidated
  by a gypsum crust, to very hard (concrete-like)
  on salt
• Rock distribution varies from low to high near
  Pampa Nevada
• Angular clasts average 5cm-high, about 5-30 cm
  long and are mixed with angular, dark volcanic
  rocks averaging 5x5x3 cm
• Aeolian cover consists of ripples and dust (very
  thin) as well as ventifact carving underneath
  rocks.

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Habitats and Life Current

• Variety of Habitats and Life in explored region
• Lichens
• Extremely abundant in Pampa Nevada limestone.
  Cover could reach 80 of the rock Very close to
  the rover.
• Alluvial fan material (20-30 in average, can go
  up to 75/m2
• Absent on
• Volcanic material
• Gravelly surfaces
• Polygons (dynamic) formations

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Diversity of Habitats Current

• Surface of rocks (Pampa Nevada, abundant)

These lichens were particularly abundant in the
landing site area in region close and accessible
to the rover. No such abundance was found
anywhere else in the study area Exposure?
Material?
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Diversity of Habitats Current

• Alluvial Material and Gypsum Crust
• High sensitivity to exposure, elevation, and
  substratum Example could be seen abundant on
  one wall of a gully but not on the other.

Large variety of lichens from dessicated to
blooming. Habitat Gypsum crust on alluvial
material Location over the entire site.
Discontinuity in abundance.
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Biotic vs. Mineralogic?

• Near Pampa Nevada
• Green material in the first few mm of salt. Dark
  filaments also. Mineralization or biological
  origin? (see Alan?). Could not be determined in
  the field.

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Past Life Modern and Jurassic Fossils
Jurassic Coral (left). This large specimen was
found outside the exploration area (North Pampa
Nevada). However, small examples were located in
the surveyed zone. Density 3 fossil/km2, size
(cms) Right Fossil Bone (modern).
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Current Life

• Insects (rampant and airborne --flies)
• Birds of prey
• Other (imported) Dogs (farms and mines)

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Genuine Discovery?
Troglodyte lichens? Brown lichen colonize the
surface of the gypsum crust on alluvial fan
material. When turned over, the interior of the
crust is blanketed with alluvial fan material.
Blooming lichen were discovered, not only at the
border of the crust but deep toward the center.
(More humidity, less wind? T?). Hole is gypsum
crust leave space for light to enter.
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Conclusion Ground-Truth Yr.1

• Hyperion and ASTEP team are the first to perform
  astrobiological study of this region. Geology
  surveyed only for mining purposes (salt)
• Diversity within uniformity of Life and Habitats
  in modern Humid Atacama A lot but mostly
  lichens
• Most of it is extremely habitat specific
  sensitive to orientation, topography, elevation,
  geological substrate Life can disappear within
  meters.
• Past life includes fossils of Jurassic corals
• More recent fossils in the landing area
  included occurrences of egg-shells, ursins, and
  bones
• Genuine discovery? To be documented in the
  coming months.