Data release for Surficial Geology of the Northern San Luis Valley, Saguache, Fremont, Custer, Alamosa, Rio Grande, Conejos, and Costilla Counties, Colorado

The San Luis Valley and associated underlying basin of south-central
Colorado and north-central New Mexico is the largest structural and
hydrologic basin of the Rio Grande Rift and fluvial system.  The
surrounding San Juan and Sangre de Cristo Mountains reveal evidence
of widespread volcanism and transtensional tectonism beginning in
the Oligocene and continuing to the present, as seen in fault
displacement of Pleistocene to Holocene deposits along the eastern
basin-bounding Sangre de Cristo fault system and fault zones along
the western margin of the basin.  The San Luis basin can generally
be subdivided into northern and southern basins at the structural
and physiographic high terrain of the San Luis Hills in the center
of the basin, proximal to the Colorado-New Mexico stateline.  The
northern San Luis Valley can be subdivided into two subbasins at
approximately the latitude of the Great Sand Dunes and San Luis
Lakes, where the endorheic northern subbasin surface and subsurface
flow currently accumulate in a series of playa lakes. To the south
of this playa region, the Rio Grande has captured basin hydrology
into a through-going fluvial system cutting through the San Luis
Hills, carving the Rio Grande gorge, and ultimately flowing into
the Gulf of Mexico.  This surficial geologic map of the northern
San Luis Valley, paired with the Alamosa, CO 1:100,000-scale
geologic map (U.S. Geological Survey Scientific Investigations Map
3342) provides new and compiled geologic mapping that characterizes
basin deposits and locates the traces of active faults, with the
goal to provide geospatial data for future investigations related to
western North American neotectonics, Pleistocene paleoclimate, and
related geomorphic processes.  In addition, present natural and
anthropogenic water bodies have been located and updated for
hydrologic modeling and water-usage investigations.

Tags: 3he-cosmogenic-nuclide, active-fault, alamosa, alamosa-county, alamosa-river, bishop-tuff, blanca-peak, bull-lake-age, bull-lake-glaciation, center, chiquita-peak, colorado, conejos-county, conejos-river, costilla-county, crestone, custer-county, del-norte, early-pleistocene, fort-garland, fremont-county, great-sand-dunes, greenie-ridge, hayden-pass, holocene, huckleberry-ridge-tuff, la-jara-creek, la-veta-pass, lake-alamosa, landslides, late-middle-pleistocene, late-pleistocene, lava-creek-b, marine-oxygen-isotope-stage-10, marine-oxygen-isotope-stage-11, marine-oxygen-isotope-stage-12, marine-oxygen-isotope-stage-2, marine-oxygen-isotope-stage-5, marine-oxygen-isotope-stage-6, marine-oxygen-isotope-stage-7, marine-oxygen-isotope-stage-8, marine-oxygen-isotope-stage-9, marine-terrestrial-marine-isotope-correlation, medano-creek, medano-pass, middle-pleistocene, middle-pleistocene-glaciation, mineral-hot-springs-fault, miocene, miocene-volcanics, moffet, monte-vista, mosca-pass, neogene, neotectonics, oligocene, orient-iron-mine, pinedale-age, pinedale-glaciation, pleistocene, pleistocene-glaciation, pleistocene-river-incision, pliocene, pliocene-volcanics, poncha-pass, pre-bull-lake-age, pre-bull-lake-glaciation, quaternary, rio-grande, rio-grande-county, rio-grande-incision, rio-grande-rift, rocky-mountain-glaciation, saguache, saguache-county, saguache-creek, san-juan-mountains, san-juan-volcanic-field, san-luis-basin, san-luis-creek, san-luis-lakes, san-luis-valley, sand-creek, sangre-de-cristo-fault, sangre-de-cristo-fault-system, sangre-de-cristo-mountains, santa-fe-group, servilleta-basalt, soil-carbonate, taos-plateau-volcanic-field, terrace-reservoir, tertiary, tusas-mountains, united-states, usa, usgs-5f46b7c182ce4c3d122576e8, valley-view-hot-springs, villa-grove, villa-grove-fault-zone, zapata-creek, zapata-falls
Organization: Department of the Interior