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dc.contributor.authorNereson, Alexander
dc.date.accessioned2012-08-27T21:39:09Z
dc.date.available2012-08-27T21:39:09Z
dc.date.issued2012-08-27
dc.date.submittedJuly 2012
dc.identifier.urihttp://hdl.handle.net/1928/20997
dc.description.abstractThe causal mechanisms for the onset and patterns of post-Miocene erosion of the western Great Plains remain the subject of an enthusiastic debate between the roles of climatically-modulated geomorphic parameters and tectonic rock uplift as drivers of long-term erosion. This study distinguishes between these drivers on the plains of New Mexico and Colorado where post-Miocene erosion and late Cenozoic volcanism of the Jemez lineament have produced distinctive modern landscapes characterized by deep bedrock canyons and inverted, basalt-capped mesas. 40Ar/39Ar ages are used to define an episodic eruption history in the Raton-Clayton volcanic field and to quantify denudation rates from flow-capped paleosurfaces. Several datasets indicate patterns of surface topography that are consistent with dynamic rock uplift along a NE-trending flexural bulge above the Jemez low-velocity mantle anomaly, but are not well-explained by climate. They include: (1) crude volcanic “belts” of similar age, (2) retreating erosional escarpments, (3) differential landscape denudation measured from a NE-trending hinge-line of “low-to-no” erosion, (4) a NE-trending zone of broad (50-100km) convexities in stream profiles identified by an analysis of channel steepness (5) reorganization of stream networks from ESE-flowing streams, to a SSE flowing Canadian River that takes advantage of a relative base level fall in the SE, and (6) a ~150-km-long, 40Ar/39Ar-dated composite paleosurface which indicates total tilting of 64 millidegrees/Ma (and ~34 millidegrees/Ma of tectonic tilting) since 3.4 Ma. Proposed mantle-driven rock uplift along the NE-trending Jemez zone is overprinted on N-S trending mid-Tertiary uplift of the Rocky Mountain orogenic plateau relative to the Great Plains.en_US
dc.language.isoen_USen_US
dc.subjectdynamic topographyen_US
dc.subjectlandscape evolutionen_US
dc.subjectargon geochronologyen_US
dc.subjectJemez lineamenten_US
dc.subject.lcshNeotectonics--Great Plains.
dc.subject.lcshErosion--Great Plains.
dc.subject.lcshClimatic geomorphology--Great Plains.
dc.subject.lcshEpeirogeny--Great Plains.
dc.subject.lcshVolcanism--New Mexico.
dc.titleDynamic topography of the western Great Plains : geomorphic and 40Ar/39Ar evidence for mantle-driven uplift associated with the Jemez lineament, New Mexico and SE Coloradoen_US
dc.typeThesisen_US
dc.description.degreeEarth and Planetary Sciencesen_US
dc.description.levelMastersen_US
dc.description.departmentUniversity of New Mexico. Dept. of Earth and Planetary Sciencesen_US
dc.description.advisorKarlstrom, Karl
dc.description.committee-memberScuderi, Louis
dc.description.committee-memberCrossey, Laura


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