Controversial Origin of Central Utah's Geologic Complexities

摘要

Geology, a somewhat inexact science, differs from the more precise sciences such as chemistry and physics. In geology, many complex rock exposures are not readily decipherable, and consequently lend themselves to differing interpretations. Geologists have a wry jest: one outcrop, two geologists, three interpretations. Regrettably, the enigmatic exposures in central Utah invite such unbridled speculation. Despite the hordes of geologists who have swarmed over central Utah during the past half century, no firm consensus has been reached concerning central Utahs tangled geologic history. Contending geologists, in hot debate, have commonly offered two dramatically different interpretations. One interpretation, proposed more than half a century ago, suggests that mountain-building forces commonly referred to as tectonic forces coming from the west repeatedly deformed central Utah. This interpretation, here termed the multiple-tectonic concept, is favored by many geologists (DeCelles and others, 1995; Lawton, 1985; Standlee, 1982). A second interpretation, relatively new, proposes that the structural deformation in central Utah is best explained as the result of the repeated growth and collapse of large salt masses known as salt diapirs the salt-diapiric concept (Witkind, 1983; 1987; 1994). I contend that the contained salt in the Arapien Shale expressed as salt diapirsis the driving force that complexly deformed the rocks in central Utah. If valid, this view could have great economic significance. Elsewhere, throughout the United States and the world, large petroleum deposits are concentrated near salt diapirs comparable to those found in central Utah. One need look no farther than the Paradox Basin in southeastern Utah and southwestern Colorado to see a convincing relationship between salt diapirs and petroleum.