OF-21-02 Geologic Map of the Valley View School Quadrangle, Weld 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 14 other quadrangles in the past few years. These include La Salle to the west; Greeley to the northwest; Kersey to the north; Barnesville to the northeast; and Hardin to the east of Valley View School, all in Weld County. CGS Geologist Stephen Keller, along with field assistant Alex Marr completed the field work on this project during the 2021-22 mapping seasons. Digital ZIP download. OF-21-02D

From the Geologic History:

The Valley View School quadrangle lies in the northern part of the Colorado Piedmont where much of the topographic relief is relatively low (98 m difference between lowest and highest points in the quadrangle). The quadrangle has no natural exposures of bedrock and only a few natural exposures of surficial units. The area is covered mostly by Quaternary deposits, and bedrock residuum is present near the ground surface in areas in the upland on the west side of the quadrangle. Fresh bedrock is exposed only in a gravel pit in the northeast corner of the quadrangle. North-northwest- to south-southeast-oriented dune forms are prominent in the southern part of the quadrangle and are due to the prevalence of eolian sand at the ground surface. The present-day landscape of the Colorado Piedmont results from the downcutting and geomorphic evolution of the South Platte River and Arkansas River drainage basins mainly during late Neogene and Quaternary time. This began with removal of Paleogene and Neogene rocks and sediments that once covered Upper Cretaceous strata in the basins. The predominant Quaternary deposits in the piedmont, including those in the Valley View School quadrangle and surrounding area, are fluvial sediments of the South Platte River and its tributaries, and eolian sediments deflated from alluvium in these stream valleys and from upwind bedrock exposures in the piedmont. Most of the eastern two-thirds of the quadrangle is drained by Box Elder Creek, a north-flowing minor tributary of the South Platte River. The quadrangle’s west side is drained by Beebe Draw, another north-flowing minor tributary of the South Platte River, and a small area in the north is drained directly by the river. The Box Elder Creek valley has a maximum width of ~3 km within the quadrangle and joins the South Platte River valley at the boundary between the Valley View School and Hardin quadrangles.