[meteorite-list] Evidence of sedimentary activity in SNCs - Part 2 of 2

From: Bernd Pauli HD <bernd.pauli_at_meteoritecentral.com>
Date: Thu Apr 22 09:55:51 2004
Message-ID: <3C506672.D9C4D0C3_at_lehrer1.rz.uni-karlsruhe.de>

Hi again!


McSWEEN H.Y., Jr. (1994) What we have learned about Mars
from SNC meteorites (Invited Review in Meteoritics 29-6, 1994
November, pp. 757-779, excerpt):

Hydrology (p. 772):

The upper 10 km of the martian crust could potentially store as much as
1000 m of globally distributed water, and the existence of a
subpermafrost groundwater system of global extent has been postulated
(Clifford, 1993). Such a system would constitute only part of a larger
hydrologic cycle that includes an atmospheric leg between the equator
and poles, which would allow for long-term chemical interactions between
the atmosphere and groundwater. Circulation in more localized
hydrothermal systems could be powered by magma emplacement or meteor
impacts (Newsom, 1980; Gulick, 1991).
Zoned Mg- and Fe-rich carbonate spherules in the ALH 84001
orthpyroxenite are thought to have formed at elevated temperatures
(Mittlefehldt, 1994), possibly by precipitation from hydrothermal fluids
in the crust. The measured d13C of +41‰ for these carbonates (Grady et
al., 1994a; Romanek et al., 1994) is the most extreme value in SNC
meteorites. This isotopically heavy composition implies that martian
groundwater may be in isotopic communication with the atmosphere, in
concert with global hydrologic models.
Received on Thu 24 Jan 2002 02:54:26 PM PST