Direct measurement of the combined effects of lichen, rainfall, and temperature onsilicate weathering

Patrick V. Brady, Ronald Dorn, Anthony J. Brazel, James Clark, Richard B. Moore, Tiffany Glidewell

Research output: Contribution to journalArticle

78 Scopus citations

Abstract

A key uncertainty in models of the global carbonate-silicate cycle and long-term climate is the way that silicates weather under different climatologic conditions, and in the presence or absence of organic activity. Digital imaging of basalts in Hawaii resolves the coupling between temperature, rainfall, and weathering in the presence and absence of lichens. Activation energies for abiotic dissolution of plagioclase (23.1 ± 2.5 kcal/mol) and olivine (21.3 ± 2.7 kcal/mol) are similar to those measured in the laboratory, and are roughly double those measured from samples taken underneath lichen. Abiotic weathering rates appear to be proportional to rainfall. Dissolution of plagioclase and olivine underneath lichen is far more sensitive to rainfall.

Original languageEnglish (US)
Pages (from-to)3293-3300
Number of pages8
JournalGeochimica et Cosmochimica Acta
Volume63
Issue number19-20
DOIs
StatePublished - Oct 1 1999

ASJC Scopus subject areas

  • Geochemistry and Petrology

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