APPLICATION OF ELECTROMAGNETIC INDUCTION AT THE UPPER CAMP BIRD III ROCK GLACIER IN THE SAN JUAN MOUNTAINS, COLORADO

The San Juan Mountains (SJM) of Southwestern Colorado are known for its superior economic value in mining precious metals, however, the alpine environment of the SJM is fragile and severely affected by climate change. Climate change threatens the limited freshwater resources in the SJM, including glaciers, groundwater, and rock glaciers. They are composed of an insulating mantle of fine sediments and an outer layer of rock fragments which allows for a slower response to temperature increases.

In order to interpret hydrogeological characteristics, as well as to quantify their potential for freshwater resources, it is integral to understand the internal structure of these periglacial landforms. To obtain a detailed representation of the internal structure and determine the boundaries between resistive (rocks, sediment, and ice) and conductive materials (water and ore deposits) of the rock glacier, time-domain and frequency-domain methods along with detailed geological and geomorphological mapping will be used.

Many studies have been conducted using several geophysical methods, such as seismic refraction, gravimetry, resistivity, radio-echo surveys, GPR, and EM profilers to study the internal structure of rock glaciers. However, to date, no published research using the novel G-TEM system by Geonics has been found.

The G-TEM by Geonics Ltd. is an innovative controlled-source time-domain electromagnetic induction system. Using the G-TEM, the distribution of electrical conductivity in the subsurface can be mapped in order to characterize the internal structure of the rock glacier from 5-10 m depth and below. The EM Profiler is a frequency-domain electromagnetic induction system that will be used for the investigation of the uppermost layers of the rock glacier. For the proposed research, the use of two different systems will provide continuity across the data sets and will help validate the measurements recorded with the new equipment. The proposed research will validate the use of unique equipment in combination with traditional methods to characterize the internal structure and quantify the untapped water resource stored within the Upper Camp Bird III rock glacier located in the Camp Bird mine area in Ouray, CO, with potential application to the study of rock glaciers all over the world.