The internal structure and geodynamics of Mars inferred from a 4.2-Gyr zircon record

Autor: Zhengbin Deng, Laura C. Bouvier, Jussi Petteri Suuronen, Tim E. Johnson, Arnaud Agranier, Martin Bizzarro, Laure Martin, Frédéric Moynier, M. M. Costa, Alexander A. Nemchin, Takashi Mikouchi, James N. Connelly, Ninna K. Jensen, Matthew S.A. Horstwood
Přispěvatelé: Centre for Star and Planet Formation (STARPLAN), Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)-Faculty of Health and Medical Sciences, University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), British Geological Survey (BGS), European Synchroton Radiation Facility [Grenoble] (ESRF), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire Géosciences Océan (LGO), Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), The University of Western Australia (UWA), School of Earth and Planetary Sciences [Perth], Curtin University [Perth], Planning and Transport Research Centre (PATREC)-Planning and Transport Research Centre (PATREC)
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: 'Proceedings of the National Academy of Sciences of the USA ', vol: 117, pages: 30973-30979 (2020)
Proceedings of the National Academy of Sciences
Proceedings of the National Academy of Sciences of the United States of America
Costa, M M, Jensen, N K, Bouvier, L C, Connelly, J N, Mikouchi, T, Horstwood, M S A, Suuronen, J-P, Moynier, F, Deng, Z, Agranier, A, Martin, L A J, Johnson, T E, Nemchin, A A & Bizzarro, M 2020, ' The internal structure and geodynamics of Mars inferred from a 4.2-Gyr zircon record ', Proceedings of the National Academy of Sciences of the United States of America, vol. 117, no. 49, pp. 30973-30979 . https://doi.org/10.1073/pnas.2016326117
Proceedings of the National Academy of Sciences of the United States of America, 2020, 117 (49), pp.30973-30979. ⟨10.1073/pnas.2016326117⟩
Proceedings Of The National Academy Of Sciences Of The United States Of America (0027-8424) (Natl Acad Sciences), 2020-12, Vol. 117, N. 49, P. 30973-30979
ISSN: 0027-8424
1091-6490
DOI: 10.1073/pnas.2016326117
Popis: Significance We discovered a zircon record in a Martian meteorite that spans 4.2 Gyr, nearly the entire geologic history of Mars. Ancient zircons define a bimodal distribution with groupings at 4474 ± 10 Ma and 4442 ± 17 Ma, reflecting intense bombardment episodes triggered by the migration of the gas giant planets. A group of younger detrital zircons record ages from 1548.0 ± 8.8 Ma to 299.5 ± 0.6 Ma. The only plausible sources for these grains are the Elysium and Tharsis volcanic provinces that are the expressions of deep-seated mantle plumes. The chondritic-like Hf-isotope compositions of these zircons require the existence of a primitive and convecting mantle reservoir. Thus, these grains provide a tangible record of the deep Martian interior.
Combining U–Pb ages with Lu–Hf data in zircon provides insights into the magmatic history of rocky planets. The Northwest Africa (NWA) 7034/7533 meteorites are samples of the southern highlands of Mars containing zircon with ages as old as 4476.3 ± 0.9 Ma, interpreted to reflect reworking of the primordial Martian crust by impacts. We extracted a statistically significant zircon population (n = 57) from NWA 7533 that defines a temporal record spanning 4.2 Gyr. Ancient zircons record ages from 4485.5 ± 2.2 Ma to 4331.0 ± 1.4 Ma, defining a bimodal distribution with groupings at 4474 ± 10 Ma and 4442 ± 17 Ma. We interpret these to represent intense bombardment episodes at the planet’s surface, possibly triggered by the early migration of gas giant planets. The unradiogenic initial Hf-isotope composition of these zircons establishes that Mars’s igneous activity prior to ∼4.3 Ga was limited to impact-related reworking of a chemically enriched, primordial crust. A group of younger detrital zircons record ages from 1548.0 ± 8.8 Ma to 299.5 ± 0.6 Ma. The only plausible sources for these grains are the temporally associated Elysium and Tharsis volcanic provinces that are the expressions of deep-seated mantle plumes. The chondritic-like Hf-isotope compositions of these zircons require the existence of a primitive and convecting mantle reservoir, indicating that Mars has been in a stagnant-lid tectonic regime for most of its history. Our results imply that zircon is ubiquitous on the Martian surface, providing a faithful record of the planet’s magmatic history.
Databáze: OpenAIRE
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