16 Aug 2022
16 Aug 2022
Status: this preprint is currently under review for the journal GChron.

In situ U-Pb dating of 4 billion year old carbonates in martian meteorite Allan Hills 84001

Romain Tartèse and Ian C. Lyon Romain Tartèse and Ian C. Lyon
  • Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PL, UK

Abstract. In situ carbonate U-Pb dating studies have proliferated dramatically in recent years. Almost all these studies have targeted relatively young calcite up to Carboniferous in age. To assess the robustness of the carbonate U-Pb chronometer in deep-time, we carried out in situ U-Pb analyses in magnesite-ankerite-calcite carbonates in the martian meteorite Allan Hills (ALH) 84001. Carbonates in ALH 84001 formed at ca. 3.94 Ga, and there is little evidence that much happened to this rock since then, making it an ideal sample to test the robustness of the U-Pb system in old carbonates. We obtained a concordant date of 3941 ± 49/110 Ma (n = 14, MSWD = 2.0), which is identical to the step-leaching Rb/Sr date determined previously. These results thus confirm that old carbonates are amenable to U-Pb dating in samples that have had a relatively simple history post-carbonate formation.

Romain Tartèse and Ian C. Lyon

Status: open (until 27 Sep 2022)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on gchron-2022-21', Graham Edwards, 07 Sep 2022 reply
  • RC2: 'Comment on gchron-2022-21', Anonymous Referee #2, 12 Sep 2022 reply

Romain Tartèse and Ian C. Lyon

Romain Tartèse and Ian C. Lyon


Total article views: 224 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
159 57 8 224 18 1 2
  • HTML: 159
  • PDF: 57
  • XML: 8
  • Total: 224
  • Supplement: 18
  • BibTeX: 1
  • EndNote: 2
Views and downloads (calculated since 16 Aug 2022)
Cumulative views and downloads (calculated since 16 Aug 2022)

Viewed (geographical distribution)

Total article views: 203 (including HTML, PDF, and XML) Thereof 203 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 20 Sep 2022
Short summary
Absolute chronological constraints are crucial in Earth and Planetary Science. In recent years, U-Pb dating of calcite has provided information on the timing of diagenesis, faulting, or hydrothermalism, for example. These studies have targeted relatively young carbonates up to 300 million years old. By dating 3.9 billion years old martian carbonates using the U-Pb chronometer, we show that this system can be robust in ancient samples that have had a relatively simple history.