Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Elwood Madden, M. E. Articles by Rimstidt, J. D. GeoRef GeoRef Citation

How long was Meridiani Planum wet? Applying a jarosite stopwatch to determine the duration of aqueous diagenesis

¹ School of Geology and Geophysics, University of Oklahoma, 100 E. Boyd Street, Suite 810, Norman, Oklahoma 73019, USA
² Department of Geosciences, Virginia Tech, 4044 Derring Hall, Blacksburg, Virginia 24061, USA

Jarosite dissolution rates can be used to determine the duration of water at Meridiani Planum and other environments containing this ephemeral, metastable ferric sulfate salt. The maximum duration of aqueous fluids in the region is calculated based on the dissolution rate of jarosite under varying temperature and ionic strength conditions. Jarosite lifetimes predicted in this study range from 1.5 a in warm dilute environments to 100 ka in NaCl-saturated brines at 250 K. The preservation of jarosite within rocks at Meridiani Planum requires that aqueous fluids were active over a small fraction of the billions of years since jarosite formed or was deposited in the region, limiting the probability of life being established in such a temporally restricted system. In addition, water-related features such as hematite spherules and crystal molds must have formed relatively quickly during this geologically short period of aqueous diagenesis.