Lava Flow Vesicle Distributions as a Tool for Determining Paleo-Elevation: Application to Timing of Uplift of the Colorado Plateau and Adjacent Rocky Mountains

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ABSTRACT9909293SahagianKnowledge of the uplift history of many orogenic areas is important paleogeographic reconstructions, paleoclimate changes as well as its reflection or proxy for lithospheric thermal structure and mantle processes. However this parameter is quite difficult to measure and methods based on geomorphology, paleoflora, sedimentation and isotopic fractionation have major uncertainty stemming from using proxies which depend on factors other than elevation alone. This project will refine and apply a method that appears to rely on a minimum of such parameters or assumptions and should be applicable to areas containing vessicular volcanic flows, a common component of orogenic environments. By measuring the difference between vessicle size from flow top to bottom and flow thickness, paleoelevation can be calculated. This method will be applied to the uplift history of the Colorado Plateau, which is a source of considerable concern and debate. Results should help resolve between early and late scenarios for uplift of the Colorado Plateau and provide a significant test for this method, which will be of wide application if successful.