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Layering in the wall rock of Valles Marineris: intrusive and extrusive magmatism
Author(s) -
Williams JeanPierre,
Paige David A.,
Manning Craig E.
Publication year - 2003
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl017662
Subject(s) - geology , flood basalt , tharsis , igneous rock , basalt , layering , large igneous province , magmatism , pluton , geochemistry , volcanic rock , plateau (mathematics) , crust , magma , layered intrusion , rift , volcanism , petrology , volcano , mafic , geomorphology , paleontology , tectonics , structural basin , martian , astrobiology , physics , botany , biology , mathematical analysis , mathematics , mars exploration program
High‐resolution images of the walls exposed in Valles Marineris reveal variations in appearance and degree of layering indicating various lithologies comprise the Tharsis plateau. The layered wall rock has been proposed to result from effusive flood basalt volcanism or interbedded sediments and volcanics. We present observations of unlayered rock that indicate layering extends to a greater depth in the western half of Valles Marineris and is confined to the Tharsis plateau, a region of thickened, uplifted crust resulting from prolonged intrusive activity. Consistent with this view, we propose that the observed layering may be a manifestation of intrusive rocks resulting from crystal fractionation of intruded basaltic magmas. Terrestrial layered plutons provide analogs for comparison such as those of the North Atlantic Igneous Province (NAIP) a large igneous province associated with crustal rifting and exposures of thick sequences of layered flood basalts and intruded layered cumulates.