SGER for US-Japan Shinkai 6500 and Hyperdolphin ROV studies of the Mariana Arc

Stern 0827817摘要2008年智力成果该项目将利用两个预定的JAMSTEC巡航，研究关岛东南部的弧前和关岛西北部的海底火山。第一次航行的主要目的是在先前对马里亚纳暴露弧前地壳和上地幔的结构、组成、年龄和形成方式的研究的基础上再接再厉。早期的研究提供了关于下地壳和上地幔的信息，以及弧和弧前地壳的样本。这些数据表明，在外弧之下的地壳可能只有3公里厚，因此可以钻取完整的地壳剖面。 在这次巡航中，PI和学生将对该地区剩余的弧壳进行采样，以更好地了解构成马里亚纳弧前地壳和上地幔的岩石类型之间的几何和地质关系。此次巡航将有6名美国科学家和2名研究生参加，他们的目标是确定未来ALVIN潜水和IBM弧前南部IODP钻探的候选地点。第二次巡航的主要目的是考察南马里亚纳弧的三座海底火山，包括一座活跃的海底火山NW-Rota-1。此外，项目研究员将研究和取样三座火山之一的破火山口壁暴露的热液蚀变和网脉硫化物矿化，并对关岛以西基本上未经检查的特雷西海山进行探索性潜水。更广泛的影响这个项目代表了美国九所大学和两个联邦机构之间的合作努力，以及美国和日本科学家之间的国际合作。该项目还将帮助支持和培训三名来自不同学术机构的地球科学研究生。 这两次航行的结果将用于确定未来的大洋钻探项目。

Stern 0827817 Abstract 2008Intellectual MeritThis project will utilize two scheduled JAMSTEC cruises, to study the forearc SE of Guam and submarine volcanoes NW of Guam. The main objective of the first cruise is to build upon previous studies of the structure, composition, age, and mode of formation of the exposed Mariana forearc crust and upper mantle. Earlier studies provided information about the lower crust and upper mantle as well as samples of the arc and forearc crust. These data indicate that the crust may be only 3 km thick beneath the outer forearc, and therefore accessible for drilling complete crustal sections. On this cruise, the PIs and students will sample remaining pieces of the arc crust in the region, to gain a better understanding of the geometric and geologic relationships between rock types that make up the Mariana forearc crust and upper mantle.The cruise will involve 6 US scientists and 2 graduate students who aim to identify candidate sites for future ALVIN dives and IODP drilling in the southern IBM forearc. The main objective of the second cruise is to examine three submarine volcanoes in the Southern Mariana Arc, including NW-Rota-1, which is an active submarine eruption. Additionally, the PIs will study and sample hydrothermal alteration and stockwork sulfide mineralization exposed in the caldera wall of one of the three volcanoes, and perform an exploratory dive to the largely unexamined Tracey Seamount west of Guam. Broader ImpactsThis project represents a collaborative effort among nine US universities and two federal agencies as well as an international collaboration between scientists from the US and Japan. The project will also help support and train three Geoscience graduate students, each from different academic institutions. Results from the two cruises will be used to determine future Ocean Drilling projects.