CAVE GENESIS IN THE EASTERN GREAT BASIN OF NEVADA AND UTAH, USA

The Eastern Great Basin of Nevada and Utah contains a significant number of caves that display speleogenetic characteristics that appear to be hypogenic in nature. These characteristics include: lack of direct relationship with surface topography, morphological foot print of cave that displays ramiform or network pattern, abrupt variations of passage cross section, and had a dearth of fluvial sediments. Karst researchers have used two different approaches to identify speleogenetic processes that determine karstic cave origin. A hydrogeological approach defines cave type by overall morphology and passage feature morphologies, and through place and position in a hydrogeological system. A geochemical approach emphasizes process of dissolution, and source of aggressiveness of cave forming waters. In this study a combination of hydrogeological and geochemical parameters were considered in determining speleogenetic origin of a set of eastern Great Basin caves from Nevada and Utah. Parameteres analyzed were morphological footprint of caves, occurrence and morphology of speleogens, identification of secondary mineralization such as speleothems, crystalline coatings, mineral/clay occurrence and distribution, and identification of hydrogeological function and geochemical regime. This method was successful in differentiating cave type and associated karstic processes and illustrates the variety of processes that form caves in the Eastern Great Basin of the United States.