This research will 1)determine the provenance, depositional environment, and mechanics and direction of sediment transport for volcaniclastic sandstone bodies within the uppermost Gazelle Formation 2) determine more accurately the age of the uppermost Gazelle Formation by generating a conodont biostratigraphy 3) to better constrain the timing of amalgamation of the Yreka-Callahan terrane and the Trinity Ultramafic Complex by: a) evaluating contact relations between the Gazelle Formation and the Trinityh Ultramafic Complex and b) U-Pb dating of zircon from a pluton that cuts a thrust contact between the two terranes. This work will provide important constraints on three competing models for the accretionary history of lower Paleozoic eugeoclinal terranes in California and Nevada. In addition, the study will bear directly on any evaluation of the hypothesis that supracrustal terranes in the eastern Klamath Mountains occur within extensional allochthons. In doing so, research will fill a conspicuous gap in reconstructions of Devonian paleogeography. Existing reconstructions simply label regions in California and western Nevada as "island arc" environments. We must provide better resolution via well-constrained local geologic histories if we are to evaluate further the existing models of tectonic development outlined above.
