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Šrámek O, Zhong S. Long-wavelength stagnant lid convection with hemispheric variation in lithospheric thickness: Link between Martian crustal dichotomy and Tharsis? ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010je003597] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Olson P, Weeraratne D. Experiments on metal-silicate plumes and core formation. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2008; 366:4253-4271. [PMID: 18826918 DOI: 10.1098/rsta.2008.0194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Short-lived isotope systematics, mantle siderophile abundances and the power requirements of the geodynamo favour an early and high-temperature core-formation process, in which metals concentrate and partially equilibrate with silicates in a deep magma ocean before descending to the core. We report results of laboratory experiments on liquid metal dynamics in a two-layer stratified viscous fluid, using sucrose solutions to represent the magma ocean and the crystalline, more primitive mantle and liquid gallium to represent the core-forming metals. Single gallium drop experiments and experiments on Rayleigh-Taylor instabilities with gallium layers and gallium mixtures produce metal diapirs that entrain the less viscous upper layer fluid and produce trailing plume conduits in the high-viscosity lower layer. Calculations indicate that viscous dissipation in metal-silicate plumes in the early Earth would result in a large initial core superheat. Our experiments suggest that metal-silicate mantle plumes facilitate high-pressure metal-silicate interaction and may later evolve into buoyant thermal plumes, connecting core formation to ancient hotspot activity on the Earth and possibly on other terrestrial planets.
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Affiliation(s)
- Peter Olson
- Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA.
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Stanley S, Elkins-Tanton L, Zuber MT, Parmentier EM. Mars' Paleomagnetic Field as the Result of a Single-Hemisphere Dynamo. Science 2008; 321:1822-5. [PMID: 18818355 DOI: 10.1126/science.1161119] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Sabine Stanley
- Department of Physics, University of Toronto, Toronto, ON M5S1A7, Canada
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - Linda Elkins-Tanton
- Department of Physics, University of Toronto, Toronto, ON M5S1A7, Canada
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - Maria T. Zuber
- Department of Physics, University of Toronto, Toronto, ON M5S1A7, Canada
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - E. Marc Parmentier
- Department of Physics, University of Toronto, Toronto, ON M5S1A7, Canada
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
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