OF-23-03 Geologic Map of the Loveland Quadrangle, Larimer County, Colorado

The Loveland quadrangle is situated in the northern part of the Colorado Piedmont section of the Great Plains. The Upper Cretaceous Niobrara and Pierre Shale underlie the quadrangle and record some of the final sequences of the Cretaceous Western Interior Seaway. They dip at around 18 to 25 degrees on the western border of the mapped area where the units comprise portions of the characteristic Front Range hogbacks. Dips rapidly decrease to the east. Two faults may exist in the subsurface: one on the west side of the quadrangle associated with structures mapped in the adjacent Masonville quadrangle, and the Windsor Wrench Fault Zone (WWFZ) on the eastern side of the quadrangle. The WWFZ may attenuate in lower, softer units in the subsurface, resulting in a monocline structure. From the Middle Pleistocene through the Holocene, fluvial, mass-wasting, and eolian systems have deposited units that mantle much of the bedrock in the quadrangle. Alluvial deposits record periods of deposition and erosion associated with climate fluctuations during glacier and inter-glacial periods. Fluvial units in the area and in the quadrangle are quarried for aggregate resources. The most prominent natural hazards are flooding in low-lying areas, especially adjacent to the Big Thompson River, and swelling and collapsing soils in areas underlain by the Pierre Shale and eolian sediments.