[meteorite-list] Emerging Underground Aquifers Formed Martian Lakes, Seas

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 19 Oct 2010 13:43:18 -0700 (PDT)
Message-ID: <201010192043.o9JKhIVN013566_at_zagami.jpl.nasa.gov>

NEWS RELEASE FROM THE PLANETARY SCIENCE INSTITUTE

SENT:
Oct. 18, 2010

FROM:
Alan Fischer
Public Information Office
Planetary Science Institute
520-622-6300
520-885-5648
fischer at psi.edu


Emerging Underground Aquifers Formed Martian Lakes, Seas


Researchers at the Planetary Science Institute have found a
new explanation for how seas and lakes may have once developed
on Mars.

J. Alexis Palmero Rodriguez, research scientist at PSI, has
been studying the Martian northern lowlands region, which
contains extensive sedimentary deposits that resemble the
abyssal plains of Earth's ocean floors. It is also like the
floors of other basins on Mars where oceans are thought to have
developed.
 
The origin of these deposits and the formation of Martian lakes
and seas are controversial. One theory is that there was a
sudden release of large volumes of water and sediment from
zones of apparent crustal collapse known as "chaotic terrains."
However, these zones of collapse are on the whole rare on Mars,
while the plains deposits are widespread and common within
large basin settings, Rodriguez said.

Citing evidence found in the planet's northern plains south of
Gemini Scopuli in Planum Boreum, Rodriguez proposes in an
article published in Icarus that groundwater emerged through
extensive and widespread fractures forming the floors of
ancient continental-scale basins on Mars. This led to the
formation of river systems, large-scale regional erosion,
sedimentary deposition and water ponding.
 
This model does not require sudden massive groundwater
discharges, he said. Instead, it advocates for groundwater
discharges being widespread, long-lived and common in the
northern plains of Mars.
 
"With the loss over time of water from the subsurface aquifer,
areas of the northern plains ultimately collapsed, creating
the rough hilly surfaces we see today. Some plateaus may have
avoided this fate and preserved sedimentary plains containing
an immense record of hydrologic activity," he said. "The
geologic record in the collapsed hilly regions would have been
jumbled and largely lost.

"This model implies that groundwater discharges within basin
settings on Mars may have been frequent and led to formation of
mud pools, lakes and oceans. In addition, our model indicates
this could have happened at any point in the planet's history,"
he said. "There could have been many oceans on Mars over time."

If life existed in Martian underground systems, life forms could
have been brought up to the surface via the discharges of these
deep-seated fluids. Organisms and their fossils may therefore
be preserved within some of these sedimentary strata, Rodriguez
said.


CONTACT:
J. Alexis Palmero Rodriguez
Research Scientist
Planetary Science Institute
520-622-6300
alexis at psi.edu
 
 
PSI INFORMATION:
Mark V. Sykes
Director
520-622-6300
sykes at psi.edu

PSI HOMEPAGE:
http://www.psi.edu

PSI PRESS RELEASES:
http://www.psi.edu/press/
Received on Tue 19 Oct 2010 04:43:18 PM PDT