COLLABORATIVE RESEARCH: Tectonothermal Evolution during Collisional Orogenesis: Blueschist to Granulite facies Metamorphism in the Kigluaik Mountains, Alaska

阿拉斯加的Kigluaik山脉含有麻粒岩相(高温)变质叠加在相对较冷的高压绿帘石-蓝片岩上。关于这种并置的两个相互竞争的假设是：(1)它代表了一个伸展变质核杂岩，在不同级别的岩石之间有明显的构造破裂；(2)高温变质作用是对增厚的地壳热再平衡的反应，没有构造破裂。这项研究将通过野外工作、岩石学和地质年代学的综合程序直接检验第二个假设。它还将评估高品位岩石的热传输机制。这一结果将对造山带深部在碰撞后立即形成的热史提供重要的约束，因此具有广泛的构造意义。

The Kigluaik Mountains in Alaska contain a granulite facies (high-temperature) metamorphic overprint on relatively cool, high pressure, epidote-blueschist rocks. Two competing hypotheses for this juxtaposition are (1) that it represents an extensional metamorphic core complex with a pronounced structural break between the different grade rocks, and (2) that the high temperature meta- morphism formed in response to thermal re-equilibration of thickened crust with no structural break. This study will directly test the second hypothesis by an integrated program of field work, petrology and geochronology. It will also evaluate heat transport mechanisms for the high grade rocks. The results will provide important constraints on the thermal history of deep seated parts of orogens immediately post-collision, and will thus have wide tectonic significance.