By: R. F. Biek, D. W. Moore, and L. D. Nealey
The Henrie Knolls 7.5' quadrangle is in the central Markagunt Plateau, east of Cedar City in southwestern Utah. The quadrangle is dominated by typically heavily forested exposures of the red member of the Claron Formation, which is spectacularly exposed to the northwest at nearby Cedar Breaks National Monument, and by sparsely vegetated late Pleistocene and possibly Holocene basaltic flows. Dissolution of carbonate beds in the Claron Formation created numerous sinkholes, many of which involve overlying lava flows; this karst topography greatly affects the movement of surface water and groundwater across the quadrangle. The Henrie Knolls lava flow complex is the largest in the quadrangle and erupted from more than 20 vents that are strikingly aligned in a northeast direction, subparallel to small normal faults in the region. Claron and underlying Upper Cretaceous strata dip gently to the east-northeast, illustrating the overall simple structure of the central part of the plateau.
Included are two plates - the geologic map at 1:24,000 and the explanation sheet - both.
Plates: 2 pl.
Location: Garfield County, Iron County, and Kane County
Media Type: Paper Map