Collaborative Research: Batholiths: Generation and Evolution of Crust in Continental Magmatic Arcs

合作研究：岩基：大陆岩浆弧中地壳的生成和演化

• 批准号: 0310126
• 负责人: John Hole
• 金额: $ 51.11万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0310126&HistoricalAwards=false
• 关键词: Collaborative; Research; Batholiths; Generation; Evolution

0310126HoleThe goal of this project is to establish the existence or absence of mafic-ultramafic roots to batholiths and whether such roots can reconcile the fundamentally basaltic nature of mantle magmatism with the intermediate average composition of the crust. Two hypotheses are considered: 1) that the dense ultramafic residue founders into the mantle leaving the intermediate crustal compositions above, or 2) the residue exists below the Moho and is seismologically indistinct from mantle peridotite. The PIs will use a combination of petrology, geochemistry and geochronology on the plutons of the Central Coast Range Batholith to track changes in source, depth of origin through time and seismic and gravity data to image the present state of the lithosphere. The Central Coast Range Batholith (CCRB) in British Columbia is a very good location for this study. It is a very large batholith which is relatively young and has not had a protracted tectonic history. It's rugged topography gives access to depth profiles of 20 to 25 km.

0310126Hole 该项目的目标是确定岩基是否存在镁铁质-超镁铁质根，以及这些根是否能够调和地幔岩浆作用的玄武岩本质与地壳的中间平均成分。 考虑了两种假设：1）致密的超镁铁质残留物沉入地幔中，留下中间地壳成分在上面，或2）残留物存在于莫霍面下方，并且在地震学上与地幔橄榄岩没有区别。 PI 将结合岩石学、地球化学和地质年代学来研究中央海岸山脉基岩的岩体，以跟踪源头、起源深度随时间的变化以及地震和重力数据，以对岩石圈的当前状态进行成像。 不列颠哥伦比亚省的中央海岸山脉基基（CCRB）是这项研究的一个非常好的地点。 这是一个非常大的岩基，相对年轻，没有悠久的构造历史。 其崎岖的地形使其能够进入 20 至 25 公里的深度剖面。