GEOLOGIC MAPPING OF THE UPPER CAMP BIRD III ROCK GLACIER IN THE SAN JUAN MOUNTAINS, COLORADO

The basement rock in the San Juan Mountains is composed of Vallecito conglomerate of Proterozoic age, followed by an angular unconformity causing a gap in the geologic record for a portion of the Paleozoic era (Ordovician and Silurian). Marine sedimentary rock (limestones and dolomites) of Devonian and Mississippian age directly overlay the metamorphic basement rock. Marine transitional to continental sedimentary rocks (conglomerates, sandstones, and shales with interbedded fossiliferous limestones) of Pennsylvanian and Permian age overlie the carbonate sequence. There is another angular unconformity in which the Mesozoic rocks (shales, mudstones, sandstones, limestones, breccias, and conglomerates) overlay the Paleozoic section. Volcanism from the Rocky Mountain building event and local eruptions from the surrounding Calderas volcano occurred in the mid-Tertiary covering the region with andesites and rhyolites, and tuff breccias of intermediate composition. Three known orogenic events occurred within the area, resulting in ore deposit formation. Finally, the subsurface is composed of Pleistocene glacial deposits and Holocene alluvial deposits.

The predominant lithologies in the study area are Mesozoic and Cenozoic. Orogenic events caused alteration of intrusive igneous rock as mineral rich, hydrothermal fluids deposited economically valuable minerals it the region. As a result of these processes, the Ouray mining district is known for its silver, copper, lead, zinc, and most importantly gold resources. One of the most productive mines in Ouray is Camp Bird Mine, it produced from the 1890’s until the early 2000’s, and is the namesake for the rock glacier of interest.

The proposed research will study the internal composition of the Upper Camp Bird III rock glacier. Traditional geological and geomorphological mapping techniques will be complemented with the use of unmanned aerial vehicles (UAV). Geophysical surveys will be done to describe and interpret the internal structure of the rock glacier. The next phase of the project will be to use the geological, geomorphological and geophysical interpretations to produce a hydrogeological model of the rock glacier. With this model, the water resources stored in the rock glacier will be quantified and characterized.