SGER: IODP Site Survey participation YK-0905, Tectonic and petrologic evolution of Godzilla Mullion

低角度滑脱断层可以在缓慢扩散的岩浆匮乏的山脊上引发地壳的吸积，产生被称为海洋核心杂岩(OCC)的结构。Parece Vela裂谷(PVR)的OCC是已知的最大的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弧后的下地壳和上地幔提供了相对容易的途径。这项研究的主要目标将是获得有关滑脱表面下的下盘岩块性质的初步数据。这项研究将促进对核杂岩类型海洋地壳形成的理解，提供与在大西洋和印度洋观察到的情况的比较。人们对这种类型的地壳形成知之甚少，使用现有的海洋地壳成因的蛇绿岩模型也不容易预测。因此，按照这次巡航的计划，对OCC的调查最好是通过直接海底观测来实现。更广泛的影响：该项目为美国和日本科学家之间提供了强有力的国际合作，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的一项重要的现场调查。它涉及两名美国科学家和两所大学的两名学生。该项目将帮助两名研究生进行研究，并为他们提供收集样本和与国际科学家团队直接交流的亲身机会。它还为其中一名学生提供了适度的暑期支持。

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.