Mobility and Storage of Volatiles in Forearcs: The Metamorphic Record

9805050贝布特这项研究将考察深部增生岩中挥发分的去挥发或保留程度，作为前弧深处P-T历史的函数。这项综合的野外、岩石学和地球化学工作将集中在以前详细的岩石学和热年代学研究对前行和后退变质演化提供限制的岩套上，并将重点放在预计俯冲旋回对其具有重要意义的某些火山碎屑组分上。不同程度挥发分损失的证据将与目前的矿物学和推断的高级变质反应历史联系在一起。这项研究还将提供关于低T、高P/T变质岩套保存高P/T流体的同位素组成和来源的程度、深孔隙水俯冲的程度以及前弧深部流体活动规模的信息。油田区域将包括西巴哈地体和部分Fransciscan建筑群。第二项任务将在海岸山脉的选定曝光中进行研究。

9805050 Bebout This research will examine the extents of devolatilization or retention of volatile components in deeply accreted rocks as functions of P-T history deep in forearcs. This integrated field, petrologic and geochemical work will concentrate on suites for which previous detailed petrologic and thermochronological studies have provided constraints on prograde and retrograde metamoprhic evolution, and will focus on selected voaltile components for which subduction cycling is expected to be important. The evidence for varying degrees of volatile loss will be linked with present mineraology and inferred prograde metamorphic reaction histories. The reserach will also provide information regarding the degree to which low-T, high-P/T metamorphic suites preserve a record of the isotopic compositions and sources of high-P/T fluids, the extents of deep pore water subduction, and the scales of fluid mobility at depth in forearcs. The field areas will include the Western Baja Terrane and parts of the Fransciscan Complex. The second task will be studied in selected exposures in the Coast Ranges.