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Details for article 59 of 114 found articles
| Title: |
Geochemistry of biogenic pyrite and ferromanganese coatings from a small watershed: A bacterial connection? |
| Author: |
Saunders, James A. Pritchett, Mason A. Cook, Robert B. |
| Appeared in: |
Geomicrobiology journal |
| Paging: | Volume 14 (1997) nr. 3 pages 203-217 |
| Year: |
1997-07 |
| Contents: |
Present-day groundwater in an alluvial aquifer in Holocene floodplain deposits in east-central Alabama contains 0.1-4 mg/L Fe, 0.1-0.7 mg/L Mn, ∼1-10 μg/L each of Co, Ni, As, Zn, La, and Ce, and 40-175 μ/L Ba. There is a distinct correspondence between trace elements present in groundwater and those concentrated on ferromanganese coatings on present-day stream alluvium in the study area. This indicates that the reduction and dissolution of such coatings in the alluvial aquifer, probably mediated by Fe- and Mn-reducing bacteria, has been a major control on groundwater chemistry. Authigenic euhedral pyrite crystals up to 1.5 cm in diameter replace lig-nitic macro wood fragments near the base of the alluvial aquifer, and sulfur isotope data (δ34S values from +3 to -40‰CDT) indicate that pyrite precipitated as a consequence of bacterial sulfate reduction in and adjacent to the irregularly distributed wood fragments. The authigenic pyrite contains several hundred parts per million of As, Co, and Ni, indicating that these trace elements were coprecipitated in pyrite during bacterial sulfate reduction. Results suggest a strong geomicrobiological control on trace element cycling in the study area. |
| Publisher: |
Taylor & Francis |
| Source file: |
Elektronische Wetenschappelijke Tijdschriften |
Details for article 59 of 114 found articles
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