Other
Scientific paper
May 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005gecoa..69.2431h&link_type=abstract
Geochimica et Cosmochimica Acta, Volume 69, Issue 9, p. 2431-2440.
Other
9
Scientific paper
Whether water has played a role in the petrogenesis of martian basalts remains a subject of significant debate. Estimates of pre-eruptive water concentrations in martian magmas are impeded by the effects of degassing and shock. However, zoning trends of light lithophile elements (LLE) in pyroxene have been interpreted as evidence for the degassing of magmatic water, on the basis of the soluble behavior of these elements in hydrothermal fluids. We provide ion microprobe analyses of LLE in pyroxene in the Zagami and Shergotty martian basalts, complemented by detailed electron microprobe analyses and major-element X-ray maps, to independently verify the zoning of LLE and its relationship to texture and major-element variations. Our results corroborate previous results; specifically, that Li concentrations are lower in rims than cores of Shergotty and Zagami pyroxene. In contrast, we see no evidence for a core-to-rim decrease in B. In the absence of further data, we interpret the decrease in Li as reflecting either loss after crystallization of pyroxene cores, consistent with magmatic degassing, or the diffusive preferential loss of Li from pyroxene rims, possibly as a result of shock. Because the partitioning behavior of Li between hydrous fluid, minerals, and melt under relevant conditions of pressure, temperature, and melt composition is unknown, the viability of the water degassing hypothesis depends on experiments establishing the compatibility of Li in hydrous fluid associated with martian basaltic melt and the incompatibility of Li in pyroxene at elevated pressures.
Herd Christopher D. K.
McKay Gordon A.
Shearer Charles K.
Treiman Allan H.
No associations
LandOfFree
Light lithophile elements in martian basalts: Evaluating the evidence for magmatic water degassing does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Light lithophile elements in martian basalts: Evaluating the evidence for magmatic water degassing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Light lithophile elements in martian basalts: Evaluating the evidence for magmatic water degassing will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1434729