MONTANA BUREAU OF MINES AND GEOLOGY: GEOLOGIC MAPPING IN MONTANA

This poster highlights current geologic mapping projects at the Montana Bureau of Mines and Geology (MBMG). Our mapping program is primarily funded by state and federal taxpayer dollars as part of the STATEMAP component of the USGS National Cooperative Geologic Mapping Program. MBMG’s mapping team comprises 12 permanent, emeritus, and contract field geologists, GIS specialists, cartographers, and laboratory assistants. The primary goal of MBMG’s mapping program is to complete geologic mapping of all 30’ x 60’ quadrangles in the state and achieve seamless geologic coverage at 1:100,000- scale. The 2023 field season focused on new mapping of seven 7.5’ quadrangles (1:24,000-scale). These maps contribute towards completing the Dillon and Wisdom 30′ x 60′ quadrangles, the final 1:100,000-scale STATEMAP projects in southwestern Montana. Mapping in the Polson 30′ x 60′ quadrangle resumed in 2023, with the support of the Confederated Salish and Kootenai Tribes. This project has important implications for seismic hazards associated with the active Mission Fault. In addition to these projects, the Economic Geology program recently began mapping four 7.5’ quadrangles in the Radersburg and Mineral Point mining districts, as part of the USGS Earth Mapping Resources Initiative.

This past year, five new 1:24,000-scale geologic maps were published by MBMG; two of which were EDMAP products authored by Montana State University students. We also published a 1:55,000-scale geologic map related to a seismic hazards study of the Bitterroot Fault. Seven datasets of geochemical, geochronological, and assay data from across the state were published as part of our new Analytical Dataset publication series. This new publication series will facilitate access to growing analytical datasets generated by MBMG annually. The first-ever Montana Geologic Map puzzle was also released this year.

In the upcoming field season, MBMG geologists will wrap up mapping in the Dillon 30′ x 60′ quadrangle, and continue our shift to mapping the ten remaining 30’ x 60’ quadrangles in the northwestern part of the state.

Learn more at https://www.mbmg.mtech.edu and view our 1:100,000-scale seamless database at https://gis-data-hub-mbmg.hub.arcgis.com/apps/53bf38cf17fd45dbbcf93b6cafaa3365/explore