OF-23-06 Geologic Map of the Wiggins Quadrangle, Morgan County, Colorado

The purpose of this publication is to describe the geology, geologic resources, and geologic hazards of this 7.5-minute quadrangle. It is a continuation of field mapping work on the northern Front Range of Colorado where the CGS has cumulatively mapped over a dozen other quadrangles in the past several years. These include La Salle, Greeley, Kersey, Barnesville, Hardin, and Valley View School, all located northwest of Wiggins in Weld County. CGS geologists Stephen Keller and Emily Perman completed the field work on this project during the 2022-23 mapping seasons. Digital ZIP download. OF-23-06D

From the abstract:

Located within the northern Colorado Piedmont, the Wiggins 7.5-minute quadrangle consists of gently sloping topography comprised of eolian-mantled uplands paired with alluvial valleys occupied by ephemeral streams. Kiowa Creek and Bijou Creek, both north-flowing tributaries to the South Platte River, are the dominant fluvial courses in the quadrangle and exhibit seasonal flow corresponding with regional rainfall events. Alluvial deposits ranging from Upper Pleistocene to Upper Holocene in age cover most of the quadrangle, filling the modern fluvial drainages as well as multiple north-south-trending paleovalleys. Upper Pleistocene dune sand deposits occupy the uplands and contain abundant compound parabolic dunes that locally enclose ponded interdune sediments. The underlying bedrock (Cretaceous Pierre Shale) is essentially flat lying, cropping out only on the eastern edge of the mapping area. Dominated by agricultural activity, the quadrangle contains few to no mineral resources, and groundwater is largely sourced from alluvial aquifers. The most pertinent geologic hazard for this area is flooding along the two major creeks, though hazards related to collapsible and/or expansive soils may also exist.