Location: Fort Lewis College, Student Union, Vallecito Room
Timing:
- 5:30 to 7:00: Happy Hour and Dinner Buffet
- 6:30 – 7:30: FCGS Business and Speaker
Speakers:
Lauren Broes, Kassandra Lindsey, Nathan Rogers – Colorado Geological Survey, Golden, CO
Abstract:
Update on recent surficial geological mapping in southwest Colorado by the Colorado Geological Survey. Geologic units include Cretaceous thru Quaternary deposits of four quadrangles between Durango, Bayfield, Ignacio and the New Mexico State line.
During the summer and fall field seasons of 2021 and 2022, the Colorado Geological Survey (thru the USGS funded STATEMAP program) have conducted surface geological mapping of four 7.5 minute quadrangles in the Durango to Ignacio area of southwest Colorado. These newly mapped quadrangles have delineated surficial extents of Cretaceous thru Eocene sedimentary formations, mapped, and placed age control on Quaternary glacial river outwash terrace deposits, identified faulting, folding, and identified past landslides. Geological Survey mappers will present their mapping and geological observations of the Loma Linda, Bondad Hill, Gem Village, and Ignacio Quadrangles. Geological units discussed will range from the recent Holocene valley fill, landslides, and colluvium, Quaternary deposits ranging from glacial outwash and terrace alluvium like Florida Mesa, and terraces along the Animas and Florida River corridors, along with rather thick red eolian loess deposits. Stratigraphic formations will include: the Paleogene San Jose Formation (including the Ditch Canyon, Regina, and Cuba Mesa Mbrs.) exposed in the Mesa Mountains, Nacimiento Formation exposed along the Animas and Florida River corridors, the Animas Formation along the foothills of the hogback and seen along Hwy 160 from Durango to Bayfield, and the McDermott, Kirtland, Fruitland and Lewis Shale formations as seen from Carbon Junction (aka Durango’s Home Depot and Walmart).