thumbnail

Dissolution of biogenic ooze over basement edifices in the equatorial Pacific with implications for hydrothermal ventilation of the oceanic crust

Geology

By:
, , ,
DOI: 10.1130/G23797A.1

Links

Abstract

Recent observations indicate that curious closed depressions in carbonate sediments overlying basement edifices are widespread in the equatorial Pacific. A possible mechanism for their creation is dissolution by fluids exiting basement vents from off-axis hydrothermal flow. Quantitative analysis based on the retrograde solubility of calcium carbonate and cooling of basement fluids during ascent provides an estimate for the dissolution capacity of the venting fluids. Comparison of the dissolution capacity and fluid flux with typical equatorial Pacific carbonate mass accumulation rates shows that this mechanism is feasible. By maintaining sediment-free basement outcrops, the process may promote widespread circulation of relatively unaltered seawater in the basement in an area where average sediment thicknesses are 300-500 m. The enhanced ventilation can explain several previously puzzling observations in this region, including anomalously low heat flux, relatively unaltered seawater in the basement, and aerobic and nitrate-reducing microbial activity at the base of the sediments. ?? 2007 The Geological Society of America.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Dissolution of biogenic ooze over basement edifices in the equatorial Pacific with implications for hydrothermal ventilation of the oceanic crust
Series title:
Geology
DOI:
10.1130/G23797A.1
Volume
35
Issue:
8
Year Published:
2007
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
679
Last page:
682
Number of Pages:
4