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
Maria M CostaMartin Bizzarro

Abstract

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...Continue Reading

References

Feb 7, 2017·Science Advances·Thomas J LapenMarc W Caffee
May 29, 2018·Science Advances·William S CassataCaroline L Smith
Jul 22, 2018·Nature Communications·Lujendra OjhaMariek Schmidt
Nov 18, 2018·Nature Communications·James M D DayClive R Neal

❮ Previous
Next ❯

Methods Mentioned

BETA
X-ray

Related Concepts

Related Feeds

Cell Migration

Cell migration is involved in a variety of physiological and pathological processes such as embryonic development, cancer metastasis, blood vessel formation and remoulding, tissue regeneration, immune surveillance and inflammation. Here is the latest research.

Related Papers

Proceedings of the National Academy of Sciences of the United States of America
Nadja DrabonDonald R Lowe
Proceedings of the National Academy of Sciences of the United States of America
Monika A KusiakKatharina Marquardt
© 2021 Meta ULC. All rights reserved