SGER: IODP Site Survey Participation YK-0905, Tectonic and Petrologic Evolution of Godzilla Mullion

低角度拆离断裂可以在缓慢扩张的岩浆缺乏的山脊上引发地壳增生，产生被称为海洋核杂岩（OCC）的结构。帕雷斯维拉裂谷（PVR）的OCC是已知最大的OCC之一，形成于岩浆匮乏的弧后盆地。PVR的这些独特特征为进入大洋后弧的下地壳和上地幔提供了相对容易的通道。本研究的主要目的是获得剥离表面下下盘块体性质的初步数据。这项研究将促进对核复型海洋地壳形成的理解，并与在大西洋和印度洋观察到的情况进行比较。人们对这种类型的地壳形成了解甚少，而且很难用现有的海洋地壳成因蛇绿岩模型来预测。因此，对OCC的调查可以最好地通过直接海底观测来实现，正如这次巡航计划的那样。更广泛的影响：该项目提供了美国和日本科学家之间强有力的国际合作，从而促进了更大的IODP社区内的交叉科学交流。它可以作为目前正在审议的IODP提案640-Full的重要现场调查。它涉及两名美国科学家和两所大学的两名学生。该项目将协助两名研究生的研究，并为他们提供一个动手收集样本的机会，并与一个国际科学家团队直接交流。它还为其中一名学生提供适度的暑期支持。

Low angle detachment faulting can initiate crustal accretion at slowly spreading magma-starved ridges, producing structures known as Ocean Core Complexes (OCC). The OCC in the Parece Vela Rift (PVR) is one of the largest known and formed in a magma-starved backarc basin. These unique features at PVR provide relatively easy access to the lower crust and upper mantle of the oceanic backarc. The primary objective of this study will be obtaining preliminary data on the nature of the footwall block beneath the detachment surface. The research will advance the understanding of core-complex style ocean crustal formation, offering comparisons with that observed in the Atlantic and Indian Oceans. This type of crustal formation is poorly understood and can not be easily predicted using existing ophiolite models of ocean crust genesis. Consequently, investigations of OCC can be best achieved through direct ocean floor observation as planned for this cruise. Broader impacts:This project provides a strong international collaboration between US and Japanese scientists and thus promotes the cross scientific exchange within the greater IODP community. It may serve as an important site survey for IODP proposal 640-Full that is currently under consideration. It involves 2 US scientists and 2 students from two universities. The project will assist the research of two graduate students, and provide them a hands-on opportunity for sample collection and direct exchange with an international team of scientists. It also provides modest summer support for one of the students.