Monday, March 13, 2017

Highlights: Caldera Sediment

Although sedimentary deposits record the history of Earth-surface processes, only infrequently they are used to understand volcanic systems. In this paper, Murphy and others study the lacustrine sedimentary rocks deposited within the Long Valley Caldera, California, to understand the evolution of the caldera. The results reveal the nature of the volcaniclastic, chemical, and biogenic sediment, from near the caldera margin (Gilbert-type delta) to distal (diatomite and marl). The interpretations suggest that deformation, volcanism, catchment area shifts, and climate change each played distinct roles in controlling the nature and extent of sediment accumulations. These data and insights provide unique perspectives on this volcanic system, understandings distinct from those offered by igneous petrology or volcanology alone, and refine the conceptual model for sedimentary processes in caldera lakes in general.



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