Hydrothermal Sites in Apollinaris Chaos

1
Hydrothermal Sites in Apollinaris Chaos
Virginia Gulick NASA Ames/SETI Institute

• Hydrothermal/fluvial sites near Apollinaris
  Patera
• Proposed by Gulick (1999, 2001) Nelson et al.
  (1999)
• Cannot fit new larger error ellipse
• Nearby acceptable sites offer similar advantages

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Thermal Energy Source

• Apollinaris Patera
• 8.5S, 186W
• Long-lived magmatic energy sources/hydrothermal
  systems
• Evidence for abundant water until late Amazonian
• Thermal spring/volcanic deposits
• Rapid burial (ash, lava, flood), mineralization
  and concentration
• Highland/Lowland
• Fluvial deposits from Maadim Valles
• Lobate crater ejecta/Chaotic terrain
• Noachian, Hesperian, Amazonian deposits and
  outcrops

3
Geology of Apollinaris
Ha1
Ha3
Ha2
Hchp
Hcht
Nm
Ha4
350 km
after Scott et al. 1993
4
Evidence for Groundwater

• Lobate ejecta blankets on small craters on flank
  above escarpment
• Chaos zones W of
  volcano

1.8 km
W. flank of Apollinaris
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Volcano-groundwater/ice Interactions
Volcanic intrusions perturb local thermal
environment for 108 years, mobilize groundwater,
spring/seep discharges, thin permafrost
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Regional Context

• Volcano lies S. of Elysium basin astride
  highland/lowland boundary
• Northward flow from Gusev and other valleys
• Volcanic impact thermal anomalies
• Many craters w/lobate ejecta
• Signs of volcano-ground ice interaction
• No MOC coverage currently

EP57A
EP58A
EP59A
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Accessible by both landers
Site 2
Site 1
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Hydrothermal/Hydrological Aspects

• Local basin
• 1 to 2 volcano radii from Apollinaris
• Adjacent to chaos regions

Gusev Maadim Vallis flows
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Appearance in MOC
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Apollinaris RegionSmooth, flat, low elevation
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Science Objectives

• Sample and characterize rocks and deposits
  emplaced by fluvial processes from the highlands.
• Sample and characterize lowlands materials, chaos
  deposits, and volcanic, fluvial and possible
  hydrothermal deposits from Apollinaris Patera.

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MER 03 Engineering Constraints

• Parameter Constraint
  Apollinaris Chaos sites
• Thermal Inertia (cgs) 5-10 cgs
  5.9 cgs ?
• Rock Abundance lt 20
  0 - 10 ?
• Fine Comp. TI gt3 to 4 cgs
  4.6 (TES) ?
• gt 3 (IRTM) ?
• Slopes lt15 deg.
  lt2 deg. ?
• Albedo low
  0.26-0.28 ?
• Elevation (MOLA) lt-1.3 km
  -2.2 km ?
• Obstacles smooth flat generally
  very smooth, flat
• some 20 m knobs
• few 100 m cliffs at margin

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Conclusions

• Hydrothermal sites meet engineering constraints
• Variety of terrain types ages (Hchp, Hcht,
  volcanic, and highland rocks) in compact region
• Variety of geologic environments can potentially
  be sampled (fluvial, paleolacustrine, H/L,
  volcanic, hydrothermal)
• Long-lived hydrothermal environments (volcano
  impact)
• Abundant evidence for groundwater/groundice
• Nice site for astrobiological exploration