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

Type Article
Date 2020-12
Language English
Author(s) Costa Maria M.1, Jensen Ninna K.1, Bouvier Laura C.1, Connelly James N.1, Mikouchi TakashiORCID2, Horstwood Matthew S. A.3, Suuronen Jussi-PetteriORCID4, Moynier Frederic5, Deng ZhengbinORCID5, Agranier Arnaud6, 7, Martin Laure A. J.8, Johnson Tim E.9, Nemchin Alexander A.9, Bizzarro Martin1, 5
Affiliation(s) 1 : Univ Copenhagen, Globe Inst, Ctr Star & Planet Format, DK-1350 Copenhagen, Denmark.
2 : Univ Tokyo, Univ Museum, Tokyo 1180033, Japan.
3 : British Geol Survey, Geochronol & Tracers Facil, Nicker Hill, Nottingham NG12 5GG, England.
4 : European Synchrotron Radiat Facil, F-38000 Grenoble, France.
5 : Univ Paris, Inst Phys Globe Paris, F-75005 Paris, France.
6 : Univ Bretagne Occidentale, Lab Geosci Ocean UMR CNRS 6538, Pl Nicolas Copernic, F-29280 Plouzane, France.
7 : Univ Bretagne Occidentale, Inst Univ Europeen Mer, Pl Nicolas Copernic, F-29280 Plouzane, France.
8 : Univ Western Australia, Ctr Microscopy Characterizat & Anal, Perth, WA 6009, Australia.
9 : Curtin Univ, Sch Earth & Planetary Sci, Perth, WA 6845, Australia.
Source 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
DOI 10.1073/pnas.2016326117
WOS© Times Cited 26
Keyword(s) Mars, meteorites, zircon, geodynamics

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.

Full Text
File Pages Size Access
Publisher's official version 7 1 MB Open access
Appendix 40 4 MB Open access
Dataset 40 KB Open access
Top of the page

How to cite 

Costa Maria M., Jensen Ninna K., Bouvier Laura C., Connelly James N., Mikouchi Takashi, Horstwood Matthew S. A., Suuronen Jussi-Petteri, Moynier Frederic, Deng Zhengbin, Agranier Arnaud, Martin Laure A. J., Johnson Tim E., Nemchin Alexander A., Bizzarro Martin (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, 117(49), 30973-30979. Publisher's official version : , Open Access version :