Direct measurement of the combined effects of lichen, rainfall, and temperature on silicate weathering
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.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (US)
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 20003978
- Journal Information:
- Geochimica et Cosmochimica Acta, Vol. 63, Issue 19-20; Other Information: PBD: Oct 1999; ISSN 0016-7037
- Country of Publication:
- United States
- Language:
- English
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