Investigation ofFluid Flow in an Ancient Subduction Zone

古代俯冲带流体流动的研究

• 批准号: 9305101
• 负责人: Donald Fisher
• 金额: $ 12.41万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-06-01 至 1996-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9305101&HistoricalAwards=false
• 关键词: Investigation; ofFluid; Flow; Ancient; Subduction

The nature of deformation hear the base of accretionary wedges likely involves extensive transport by fluids of silica and other components, brittle crack-seal veining and rock fabrics such as cleavage. However, estimates of the magnitude of fluid interactions and the scale over which they are operative is highly controversial. This project will examine the distribution, orientation, geometry, texture and geochemistry of quartz veins in a well-exposed and well-understood forearc complex on Afognak Island, Alaska. Coupled with measurements of volume change in wall rocks and oxygen isotopic analyses the plumbing system in rocks buried to depths of 8-12km will be reconstructed and used to infer the mechanisms of silica transport and the extent and nature of fluid flow near the base on an accretionary wedge. Results will be relevant to the study of accretionary, wedge development and to the study of the origins of rock deformation fabrics.

沉积楔体底部的变形性质可能涉及硅石和其他组分的流体、脆性裂缝-封闭脉和解理等岩石组构的广泛输送。然而，对流体相互作用的大小和它们发挥作用的规模的估计是非常有争议的。该项目将研究阿拉斯加州阿福纳克岛上一个暴露良好和众所周知的弧前杂岩中石英脉的分布、取向、几何形状、结构和地球化学。结合围岩体积变化的测量和氧同位素分析，将重建埋藏在8-12公里深处的岩石中的管道系统，并利用该系统来推断硅质的输送机制，以及底部附近在增生楔形上的流体流动的范围和性质。这一结果将对研究岩石的增生、楔形发育和岩石变形组构的成因具有重要意义。