Ruiz, Javierz and Williams, Jean-Pierre and Dohm, James M. and Fernández, Carlos and López, Valle (2009) Ancient heat flow and crustal thickness at Warrego rise, Thaumasia highlands, Mars: Implications for a stratified crust. Icarus, 203 (1). pp. 47-57. ISSN 0019-1035 http://resolver.caltech.edu/CaltechAUTHORS:20100615-100842561
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Heat flow calculations based on geological and/or geophysical indicators can help to constrain the thickness, and potentially the geochemical stratification, of the martian crust. Here we analyze the Warrego rise region, part of the ancient mountain range referred to as the Thaumasia highlands. This region has a crustal thickness much greater than the martian average, as well as estimations of the depth to the brittle–ductile transition beneath two scarps interpreted to be thrust faults. For the local crustal density (2900 kg m^(−3)) favored by our analysis of the flexural state of compensation of the local topography, the crustal thickness is at least 70 and 75 km at the scarp locations. However, for one of the scarp locations our nominal model does not obtain heat flow solutions permitting a homogeneous crust as thick as required. Our results, therefore, suggest that the crust beneath the Warrego rise region is chemically stratified with a heat-producing enriched upper layer thinner than the whole crust. Moreover, if the mantle heat flow (at the time of scarp formation) was higher than 0.3 of the surface heat low, as predicted by thermal history models, then a stratified crust rise seems unavoidable for this region, even if local heat-producing element abundances lower than average or hydrostatic pore pressure are considered. This finding is consistent with a complex geological history, which includes magmatic-driven activity.
|Additional Information:||© 2009 Elsevier Inc. Received 28 September 2008; revised 6 May 2009; accepted 14 May 2009. Available online 23 May 2009. J.R. was supported by a contract Juan de la Cierva for Earth Sciences, co-financed from the Ministerio de Ciencia e Innovación of Spain and the European Social Fund. J.M.D. was supported by the NASA Mars Data Analysis Program. We thank Trent Hare for Fig. 1 production, and Brian Hahn for facilitating corrected abundances for potassium and thorium in our study area. Also, we thank the comments and suggestions from two anonymous reviewers.|
|Subject Keywords:||Mars; Mars, Interior; Tectonics|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||17 Jun 2010 03:40|
|Last Modified:||26 Dec 2012 12:08|
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