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.
