Considerations of Vertical Tectonics for Big Horn Basin: ABSTRACT

Referring to the tectonic of the Big Horn basin as either or is an oversimplification. However, these terms have come into vogue and I support tectonics. This term implies that on most structures the component of displacement is larger than the horizontal component of displacement. It does not imply that all faults are absolutely vertical, nor does it preclude crustal shortening. If high-angle reverse faults (dips steeper than 45°) dominate in a basin, a net shortening will result even in a tectonic domain. Furthermore, when applied to the Big Horn basin, the expression vertical tectonic style only characterizes behavior 10 to 15 km (6 to 9 mi) into the basement. It implies nothing concerning causative condit ons in the lower crust or upper mantle. A given mantle stress condition can produce several different displacement fields in the upper crust depending upon the behavior of the crust. In accepting either horizontal or as the tectonic of a region, all of the structures produced during the deformation episode should be considered together as opposed to examining one feature at a time. It is also important to separate second and third order features from primary features. Finally, if there is a governing style, it should be consistent with three-dimensional movements, not just individual cross sections. End_of_Article - Last_Page 1357------------