The Age of the Carbonates in Martian Meteorite ALH84001

Lars E. Borg*, James N. Connelly, Larry E. Nyquist, Chi-Y. Shih, Henry Wiesmann, Young Reese

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

139 Citations (Scopus)

Abstract

The age of secondary carbonate mineralization in the martian meteorite ALH84001 was determined to be 3.90 ± 0.04 billion years by rubidium- strontium (Rb-Sr) dating and 4.04 ± 0.10 billion years by lead-lead (Pb-Pb) dating. The Rb-Sr and Pb-Pb isochrons are defined by leachates of a mixture of high-graded carbonate (visually estimated as ~5 percent), whitlockite (trace), and orthopyroxene (~95 percent). The carbonate formation age is contemporaneous with a period in martian history when the surface is thought to have had flowing water, but also was undergoing heavy bombardment by meteorites. Therefore, this age does not distinguish between aqueous and impact origins for the carbonates.

Original languageEnglish
JournalScience
Volume286
Issue number5437
Pages (from-to)90-94
Number of pages5
ISSN0036-8075
DOIs
Publication statusPublished - 1999
Externally publishedYes

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