Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
Geology Email Content Delivery
JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Geology; May 2004; v. 32; no. 5; p. 369-372; DOI: 10.1130/G20288.1
© 2004 Geological Society of America
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (20)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Engel, A. S.
Right arrow Articles by Bennett, P. C.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Microbial contributions to cave formation: New insights into sulfuric acid speleogenesis

Annette Summers Engel*,1, Libby A. Stern*,1 and Philip C. Bennett*,1

1 Department of Geological Sciences, Research Group for Microbial Geochemistry, University of Texas, Austin, Texas 78712, USA

The sulfuric acid speleogenesis (SAS) model was introduced in the early 1970s from observations of Lower Kane Cave, Wyoming, and was proposed as a cave-enlargement process due to primarily H2S autoxidation to sulfuric acid and subaerial replacement of carbonate by gypsum. Here we present a reexamination of the SAS type locality in which we make use of uniquely applied geochemical and microbiological methods. Little H2S escapes to the cave atmosphere, or is lost by abiotic autoxidation, and instead the primary H2S loss mechanism is by subaqueous sulfur-oxidizing bacterial communities that consume H2S. Filamentous "Epsilonproteobacteria" and Gammaproteobacteria, characterized by fluorescence in situ hybridization, colonize carbonate surfaces and generate sulfuric acid as a metabolic byproduct. The bacteria focus carbonate dissolution by locally depressing pH, compared to bulk cave waters near equilibrium or slightly supersaturated with calcite. These findings show that SAS occurs in subaqueous environments and potentially at much greater phreatic depths in carbonate aquifers, thereby offering new insights into the microbial roles in subsurface karstification.

Key Words: cave • hydrogen sulfide • geomicrobiology • sulfur-oxidizing bacteria • fluorescence in situ hybridization • carbonate dissolution




This article has been cited by other articles:


Home page
 Journal of Sedimentary ResearchHome page
V. De Choudens-Sanchez and L. A. Gonzalez
Calcite and Aragonite Precipitation Under Controlled Instantaneous Supersaturation: Elucidating the Role of CaCO3 Saturation State and Mg/Ca Ratio on Calcium Carbonate Polymorphism
Journal of Sedimentary Research, June 1, 2009; 79(6): 363 - 376.
[Abstract] [Full Text] [PDF]

Home page
 Appl. Environ. Microbiol.Home page
M. L. Porter and A. S. Engel
Diversity of Uncultured Epsilonproteobacteria from Terrestrial Sulfidic Caves and Springs
Appl. Envir. Microbiol., August 1, 2008; 74(15): 4973 - 4977.
[Abstract] [Full Text] [PDF]

Home page
 Geological Society of America Special PapersHome page
P. J. Boston, L. D. Hose, D. E. Northup, and M. N. Spilde
The microbial communities of sulfur caves: A newly appreciated geologically driven system on Earth and potential model for Mars
Geological Society of America Special Papers, January 1, 2006; 404(0): 331 - 344.
[Abstract] [Full Text] [PDF]

Home page
 ajsHome page
S. Douglas
Mineralogical footprints of microbial life
Am J Sci, June 1, 2005; 305(6-8): 503 - 525.
[Abstract] [Full Text] [PDF]


JOURNAL HOME HELP CONTACT PUBLISHER SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by Geological Society of America