Titre :

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

Auteur(s) :

Costa, Maria M. [Auteur]
Centre for Star and Planet Formation [STARPLAN]
Jensen, Ninna K. [Auteur]
Centre for Star and Planet Formation [STARPLAN]
Bouvier, Laura C. [Auteur]
Centre for Star and Planet Formation [STARPLAN]
Connelly, James N. [Auteur]
Centre for Star and Planet Formation [STARPLAN]
Mikouchi, Takashi [Auteur]
Horstwood, Matthew S. A. [Auteur]
British Geological Survey [BGS]
Suuronen, Jussi-Petteri [Auteur]
European Synchrotron Radiation Facility [Grenoble] [ESRF]
Moynier, Frédéric [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Deng, Zhengbin [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Agranier, Arnaud [Auteur]
Laboratoire Géosciences Océan [LGO]
Martin, Laure A. J. [Auteur]
The University of Western Australia [UWA]
Johnson, Tim E. [Auteur]
School of Earth and Planetary Sciences [Perth]
Nemchin, Alexander A. [Auteur]
School of Earth and Planetary Sciences [Perth]
Bizzarro, Martin [Auteur]
Institut de Physique du Globe de Paris [IPGP (UMR_7154)]
Centre for Star and Planet Formation [STARPLAN]

Titre de la revue :

Proceedings of the National Academy of Sciences of the United States of America

Pagination :

30973-30979

Éditeur :

National Academy of Sciences

Date de publication :

2020-11-16

ISSN :

0027-8424

Mot(s)-clé(s) en anglais :

UAT:1038
zircon
geodynamics
UAT:1007
MARTIAN MANTLE
MAGMA OCEAN
HISTORY
ORIGIN
CRUST
SYSTEMATICS
CONVECTION
MINERALOGY
AGE

Discipline(s) HAL :

Planète et Univers [physics]

Résumé en anglais : [en]

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 ...
Lire la suite >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 similar 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.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Collections :

• Laboratoire d'Océanologie et de Géosciences (LOG) - UMR 8187

Source :

Harvested from HAL