Implications of large elastic thicknesses for the composition and current thermal state of Mars
Abstract The Martian elastic lithosphere thickness Te has recently been constrained by modeling the geodynamical response to loading at the Martian polar caps and Te was found to exceed 300 km at the north pole today. Geological evidence suggests that Mars has been volcanically active in the recent...
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fttrinitycoll:oai:tara.tcd.ie:2262/47905 2023-05-15T17:40:02+02:00 Implications of large elastic thicknesses for the composition and current thermal state of Mars 2010-12-15T10:26:06Z http://hdl.handle.net/2262/47905 https://doi.org/10.1016/j.icarus.2009.01.020 en eng Elsevier 00191035 (ISSN) S0019-1035(09)00044-X (PII) S0019-1035(09)00044-X (publisherID) http://hdl.handle.net/2262/47905 Icarus 201 2 540 doi:10.1016/j.icarus.2009.01.020 2009 18 months Mars Mars interior Thermal histories Geophysics 2010 fttrinitycoll https://doi.org/10.1016/j.icarus.2009.01.020 2020-02-16T13:50:39Z Abstract The Martian elastic lithosphere thickness Te has recently been constrained by modeling the geodynamical response to loading at the Martian polar caps and Te was found to exceed 300 km at the north pole today. Geological evidence suggests that Mars has been volcanically active in the recent past and we have reinvestigated the Martian thermal evolution, identifying models which are consistent with Te>300mboxkm and the observed recent magmatic activity. We find that although models satisfying both constraints can be constructed, special assumptions regarding the concentration and distribution of radioactive elements, the style of mantle convection and/or the mantle's volatile content need to be made. If a dry mantle rheology is assumed, strong plumes caused by, e.g., a strongly pressure dependent mantle viscosity or endothermic phase transitions near the core-mantle boundary are required to allow for decompression melting in the heads of mantle plumes. For a wet mantle, large mantle water contents of the order of 1000 ppm are required to allow for partial mantle melting. Also, for a moderate crustal enrichment of heat producing, elements the planet's bulk composition needs to be 25% and 50% sub-chondritic for dry and wet mantle rheologies, respectively. Even then, models resulting in a globally averaged elastic thicknesses of Te>300 km are difficult to reconcile with most elastic thickness estimates available for the Hesperian and Amazonian periods. It therefore seems likely that large elastic thicknesses in excess of 300 km are not representative for the bulk of the planet and that Te possibly shows a large degree of spatial heterogeneity. correspondance: Corresponding author. Tel.: +49 30 67055 419. (Grott, M.) matthias.grott@dlr.de (Grott, M.) Institute of Planetary Research--> , German Aerospace Center (DLR)--> , Rutherfordstra?e 2--> , 12489 Berlin--> - GERMANY (Grott, M.) Institute of Planetary Research--> , German Aerospace Center (DLR)--> , Rutherfordstra?e 2--> , 12489 Berlin--> - GERMANY (Grott, M.) Institute of Planetary Research--> , German Aerospace Center (DLR)--> , Rutherfordstra?e 2--> , 12489 Berlin--> - GERMANY (Breuer, D.) GERMANY Received: 2008-07-22 Revised: 2009-01-15 Accepted: 2009-01-23 Other/Unknown Material North Pole The University of Dublin, Trinity College: TARA (Trinity's Access to Research Archive) North Pole Icarus 201 2 540 548 |
institution |
Open Polar |
collection |
The University of Dublin, Trinity College: TARA (Trinity's Access to Research Archive) |
op_collection_id |
fttrinitycoll |
language |
English |
topic |
Mars Mars interior Thermal histories Geophysics |
spellingShingle |
Mars Mars interior Thermal histories Geophysics Implications of large elastic thicknesses for the composition and current thermal state of Mars |
topic_facet |
Mars Mars interior Thermal histories Geophysics |
description |
Abstract The Martian elastic lithosphere thickness Te has recently been constrained by modeling the geodynamical response to loading at the Martian polar caps and Te was found to exceed 300 km at the north pole today. Geological evidence suggests that Mars has been volcanically active in the recent past and we have reinvestigated the Martian thermal evolution, identifying models which are consistent with Te>300mboxkm and the observed recent magmatic activity. We find that although models satisfying both constraints can be constructed, special assumptions regarding the concentration and distribution of radioactive elements, the style of mantle convection and/or the mantle's volatile content need to be made. If a dry mantle rheology is assumed, strong plumes caused by, e.g., a strongly pressure dependent mantle viscosity or endothermic phase transitions near the core-mantle boundary are required to allow for decompression melting in the heads of mantle plumes. For a wet mantle, large mantle water contents of the order of 1000 ppm are required to allow for partial mantle melting. Also, for a moderate crustal enrichment of heat producing, elements the planet's bulk composition needs to be 25% and 50% sub-chondritic for dry and wet mantle rheologies, respectively. Even then, models resulting in a globally averaged elastic thicknesses of Te>300 km are difficult to reconcile with most elastic thickness estimates available for the Hesperian and Amazonian periods. It therefore seems likely that large elastic thicknesses in excess of 300 km are not representative for the bulk of the planet and that Te possibly shows a large degree of spatial heterogeneity. correspondance: Corresponding author. Tel.: +49 30 67055 419. (Grott, M.) matthias.grott@dlr.de (Grott, M.) Institute of Planetary Research--> , German Aerospace Center (DLR)--> , Rutherfordstra?e 2--> , 12489 Berlin--> - GERMANY (Grott, M.) Institute of Planetary Research--> , German Aerospace Center (DLR)--> , Rutherfordstra?e 2--> , 12489 Berlin--> - GERMANY (Grott, M.) Institute of Planetary Research--> , German Aerospace Center (DLR)--> , Rutherfordstra?e 2--> , 12489 Berlin--> - GERMANY (Breuer, D.) GERMANY Received: 2008-07-22 Revised: 2009-01-15 Accepted: 2009-01-23 |
title |
Implications of large elastic thicknesses for the composition and current thermal state of Mars |
title_short |
Implications of large elastic thicknesses for the composition and current thermal state of Mars |
title_full |
Implications of large elastic thicknesses for the composition and current thermal state of Mars |
title_fullStr |
Implications of large elastic thicknesses for the composition and current thermal state of Mars |
title_full_unstemmed |
Implications of large elastic thicknesses for the composition and current thermal state of Mars |
title_sort |
implications of large elastic thicknesses for the composition and current thermal state of mars |
publisher |
Elsevier |
publishDate |
2010 |
url |
http://hdl.handle.net/2262/47905 https://doi.org/10.1016/j.icarus.2009.01.020 |
geographic |
North Pole |
geographic_facet |
North Pole |
genre |
North Pole |
genre_facet |
North Pole |
op_relation |
00191035 (ISSN) S0019-1035(09)00044-X (PII) S0019-1035(09)00044-X (publisherID) http://hdl.handle.net/2262/47905 Icarus 201 2 540 doi:10.1016/j.icarus.2009.01.020 |
op_rights |
2009 18 months |
op_doi |
https://doi.org/10.1016/j.icarus.2009.01.020 |
container_title |
Icarus |
container_volume |
201 |
container_issue |
2 |
container_start_page |
540 |
op_container_end_page |
548 |
_version_ |
1766140817534091264 |