Seven sinkholes surround the city of Sedona in Coconino and Yavapai Counties, Arizona. They occur in surface bedrock of Permian age Esplanade Sandstone, Hermit formation, and Schnebly Hill Sandstone, but the causative source is from the collapse of subsurface water-filled caves in Mississippian Redwall Limestone that underlies those formations. The original Mississippian-age Redwall karst surface has undergone two additional phases of dissolution enlargement in later geologic time. The first occurred after the Laramide uplift of the Mogollon Highlands when northeast flowing streams penetrated the exposed Redwall Limestone erosion surface, and the second took place following the generation of the Verde graben ~10 million years ago when regional drainage reversal took place.
Pre-graben Miocene basalt lava flows that overlie eroded Paleozoic strata are present on either side of, and faulted within, the Verde graben closed depression. Post-graben erosion generated the Mogollon Rim escarpment in the northern portion of the Verde Valley and allowed surface streams to erode the broad Dry Creek and Margs Draw valleys. Oak Creek fault, and the erosion of its canyon, is much younger than the faulting that generated the Verde graben. Over time water flow through the Sedona area evolved from surface flow to dominantly groundwater flow, mainly due to leakage through abundant northwest-southeast oriented rock joints and permeable fault zones into underlying cavernous Redwall Limestone.
Online Resources:
Lindberg, P.A., 2010, Sedona Sinkholes and Groundwater Flow: The Geologic History of Their Evolution, Coconino and Yavapai Counties, Arizona: Arizona Geological Survey Contributed Report CR-10-C, 67 p. and 1 map plate
http://repository.azgs.az.gov/uri_gin/azgs/dlio/1034
Lindberg, P.A., 2010, Geologic Report of the Devils Kitchen sinkhole, Sedona, Arizona: Arizona Geological Survey Contributed Report CR-10-B, 19 p.
http://repository.azgs.az.gov/uri_gin/azgs/dlio/429
