Cave and Karst Geomicrobiology

The Active and Accessible Subsurface

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Leave behind trees and sunlight, and venture into the darkness where life thrives!

 

The Kane Caves, Wyoming – the featured site for our work

We are studying several sulfidic caves that have developed in the Madison Limestone of the Bighorn Basin approximately 130 km west of Yellowstone National Park and 120 km north of Thermopolis, Wyoming, USA. The Bighorn Basin contains extensive oil fields and thermal and non-thermal springs that discharge along the flanks of the basin, and has several areas of known karstification. Most of the caves are epigenic, but several formed or were modified by sulfuric acid speleogenesis. The focus of this study is one of the caves located near Lovell, WY, where sulfidic springs and a cave stream support a rich community of microorganisms.

Other Interesting Things About Sulfur Caves

Background – introduces biogeochemical concepts to research on sulfur systems

A particularly important cave microbial community is one based on chemolithoautotrophic sulfur oxidation, where reduced sulfur compounds are used as substrates and microorganisms are able to fix carbon from carbon dioxide. Consequently, the main metabolic waste product resulting from this microbial activity is sulfuric acid.

Active Sulfidic Cave Systems – summarizes work done in other karst systems

One of the major problems interpreting caves formed by sulfuric acid speleogenesis is recognizing the mechanisms of sulfuric acid formation. However, in modern caves containing sulfidic waters, there is a wide range of microorganisms in these systems. A vast majority of them are sulfur-oxidizing bacteria that live within cave springs and streams, as well as grow on cave-wall surfaces. Some of these bacteria are reportedly acidophilic due to the production of sulfuric acid. Similar to other active sulfidic caves, we are finding evidence in the Kane Caves for a diverse ecosystem, including methanogens, sulfate-reducers, iron-oxidizers, iron-reducers, nitrogen bacteria, undifferentiated heterotrophs, as well as invertebrates such as snails and collembola.

Caves and Karst

Microbiology