Thrusting and Synorogenic Sedimentation in Central Utah: ABSTRACT
0
Citation
0
Reference
10
Related Paper
Abstract:
The thrust belt in central Utah can be divided geometrically into four major thrust systems, from west to east: the Canyon Range, the Pavant, the Gunnison, and the Wasatch thrust systems, Biostratigraphic correlations together with constraints imposed by the geometry indicate the following ages for thrusting events: late Albian for the Pavant 1 thrust, late Santonian-early Campanian for the Pavant 2 thrust, middle to late Campanian for the late Canyon Range thrust, late Maestrichtian for the Gunnison thrust system, and late Paleocene for the Wasatch thrust system. In the hinterland, a combination of structural, stratigraphic, and chronologic evidence indicates that shortening was accommodated by the development of a backbreaking (overstep) thrust sequence: Pavant 1 thrust, Pavant 2 thrust, (late) Canyon thrust. This led to the formation of successive overlapping unconformities of late Cenomanian, early-middle Campanian, and late Campanian age. In the foreland, the Gunnison thrust system has a ramp-flat geometry; a series of blind, splay, imbricate faults are associated with a major ramp beneath Sevier and Sanpete Valleys. Late Cretaceous and Paleocene unconformities coincide with the development of an imbricate fan, which was subsequently deformed during the late Paleocene by formation of a deeper duplex structure within the Wasatch thrust syst m. Associated back thrusts accommodated shortening toward the surface at the west side of the Wasatch Plateau. The times of superimposed thrusting phases, when compared with eustatic episodes recorded in the Cretaceous seaway, indicate that episodes of continental tectonism were approximately synchronous with eustatic rises in central Utah. End_of_Article - Last_Page 869------------Keywords:
Sedimentation
Bedrock
Cite
Citations (0)
Sedimentation
Constant (computer programming)
Erythrocyte sedimentation rate
Cite
Citations (3)
The Oak Ridges Moraine in southern Ontario is a poly- genetic moraine constructed of a number of coalesced deposits of gla- cifluvial and glacilacustrine origin. A detailed study of the facies ar- chitecture has been completed on a series of pit sections extending ; 300 m subparallel to the paleoflow direction. Eight major lithofacies and five facies associations have been described. These data have been interpreted to be upper-flow-regime hyperconcentrated-flood-flow de- posits emplaced under a regime of rapid flow expansion and loss of transport capacity within a plane-wall jet with an associated hydraulic jump. Deposition from the plane-wall jet with jump occurred in three zones of flow transformation: zone of flow establishment, transition zone, and zone of established flow. Massive gravels with unconsolidated sand intraclasts and open-work gravel / gravel-sand couplets were de- posited in the zone of flow establishment by hyperconcentrated and supercritical flows, respectively. Immediately downflow low-angle cross-stratified sand incised by steep-walled scours infilled by diffusely graded sand define the transition zone, the zone of maximum vortex erosion, and the distal limit of deposits emplaced under upper-flow- regime conditions. These strata record rapid bed aggradation from sediment-laden supercritical flows that episodically were scoured by large vortices generated within migrating hydraulic jumps. Strati- graphically upward and downflow strata consist only of lower-flow- regime sedimentary structures. Medium-scale, planar cross-strata and small-scale cross-lamination related to migrating 2-D dunes and cur- rent ripples, respectively, characterize the zone of established flow. The facies and sediment architecture suggest that this fan was deposited during a relatively short period of time (days, weeks) by energetic sed- iment-laden floods.
Hyperconcentrated flow
Hydraulic jump
Debris flow
Cite
Citations (130)
Caldera
Alluvial fan
Bedrock
Aggradation
Landform
Cite
Citations (30)
Outwash plain
Cite
Citations (20)