Collaborative Research: Temporal and Spatial Geochemical Variations Across the Kamchatka Arc: An Evaluation of Mantle and Crustal Contributions to Arc Magmatism

我们建议在堪察加半岛的火山弧上进行两次地质和地球化学样带。这两个样带位于不同的基底地体上，尽管两者都具有很大的海洋亲缘性。对某一地点不同年代的火山岩进行比较，将使我们能够研究岩浆成分随时间的变化。在样带之间的比较将使我们能够限制岩石圈改造（污染等）的影响。沿着趋势进行比较将有助于评估与俯冲有关的影响。贝尼奥夫带沿各样带深度的变化可能导致板源成分的性质和数量的变化，以及伴随而来的部分熔融程度的差异。该地区火山岩中非常原始的熔岩和地幔捕虏体的出现将有助于我们更好地了解来源成分和过程。这项研究将极大地促进我们对堪察加弧岩浆活动和构造的认识，以及对与俯冲有关的岩浆活动的认识。

9418645 Kepezhinskas We propose to carry out two geological and geochemical transects across the volcanic arc of the Kamchatkan Peninsula. The transects are located on different basement terranes, although both are of largely oceanic affinity. Comparison of volcanic rocks of different ages at a given location will permit us to study changes in the compositions of magmas through time. Comparison between the transects will allow is to constrain the effects of lithospheric modification (contamination, etc.). Comparison along the trends will allow evaluation of subduction-related effects. The variable depth to the Benioff zone along each transect may result in variations in the nature and amount of the slab-derived component, and concomitant differences in the degree of partial melting. The occurrence of very primitive lavas and mantle xenoliths among the volcanic rocks of the region will help us to better understand source compositions and processes. This study will significantly advance our understanding of the magmatism and tectonics of the Kamchatkan arc, and of subduction-related magmatism in general.