A GEOLOGICAL AND HYDROLOGICAL ANALYSIS OF CAVE VALLEY CAVE, LINCOLN COUNTY, NEVADA, EASTERN GREAT BASIN USA

The mountain ranges of the Eastern Great Basin of Nevada contain relict conduit systems with characteristics that suggest hypogene cave development. The valleys (basins) between mountain ranges contain many active springs that are hydrothermal in nature. Relict karst conduits within the valleys are rare exceptions. One of those exceptions is Cave Valley Cave, situated within a north-trending valley that is bounded by the Egan Mountain range to the west and the Schell Creek Mountain range to the east. The cave is formed in the upper sections of the Pioche Shale and the lower part of the Pole Creek Limestone, both of middle Cambrian age. The cave displays a linear, horizontal morphology with the exception of a 25-meter deep vent at the northern limit of the cave. The 1.2 km of surveyed passage aligns along a series of local faults. The cave passage is floored to a depth of 3 to 15 meters with fine-grained sediment and a significant portion of the sediment has been mined as evidenced by tailings at the cave entrance. The composition of the sediment in the vicinity of the vent consists of minerals that suggest hydrothermal alteration. Sediment near the entrance of the cave contains layers of organic material suggesting the influence of surface water. Scallops on the walls and ceilings as well as characteristics of the floor sediment suggest that Cave Valley Cave functioned as an epigenetic spring at some point in the geological past with a recharge area to the west in the Schell Creek mountain range. The geological and hydrogeological characteristics of Cave Valley Cave impart important insights about the current and paleo function of karst groundwater basins in the Eastern Great Basin of Nevada and the karstification of the hosting bedrock.