Rapid Growth of Magnesium-Carbonate Weathering Products in a Stony Meteorite from Antarctica

• Published in: Science
• Main Authors: Jull, A. J. T., Cheng, S., Gooding, J. L., Velbel, M. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1988
• Subjects: Antarctic; The Antarctic; Antarc*; Antarctica
• Online Access: https://doi.org/10.1126/science.242.4877.417; https://www.science.org/doi/pdf/10.1126/science.242.4877.417

Nesquehonite, a hydrous magnesium carbonate, occurs as a weathering product on the surface of the Antarctic meteorite LEW 85320 (H5 chondrite). Antarctic meteorites have resided on the earth for periods of 10 4 to 10 6 years, but the time needed for weathering products to form has been uncertain. Isotopic measurements of δ 13 C and δ 18 O indicate that the nesquehonite formed at near freezing temperatures by reaction of meteoritic minerals with terrestrial water and carbon dioxide. Results from carbon-14 dating suggest that, although the meteorite has been in Antarctica for at least 3.2 × 10 4 to 3.3 × 10 4 years, the nesquehonite formed after A.D. 1950.