Geologic, U-Pb Geochronologic and Nd Isotopic Studies of theCoast Mountains Batholith and Adjacent Terranes, SE Alaska and British Columbia

阿拉斯加东南部和不列颠哥伦比亚省海岸山脉基岩和邻近地体的地质、U-Pb 年代学和 Nd 同位素研究

• 批准号: 8917316
• 负责人: James Mattinson
• 金额: --
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 1992-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8917316&HistoricalAwards=false
• 关键词: Geologic; Pb; Geochronologic; Nd; Isotopic

The Pacific northwest continental margin was the site of extensive accretion of crustal fragments during the Cretaceous. The suturing of the Alexander and related terranes to the western margin of Stikine and other inboard terranes was accompanied by extensive magmatism that formed the Coast Mountains batholith. However, the presence of isotopically evolved material of possible North American affinity within and adjacent to the batholith raises fundamental questions about the degree of allochthoneity of all accreted terranes. This project will attempt to determine the extent of the possible North American rocks, their relationships to adjacent terranes and the age relations between them. Results will allow interpretation of the geometry of accretion- related structures in the suture zone and will provide constraints on the origin and displacement history of the stikine terrane.

太平洋西北大陆边缘是白垩纪期间地壳碎片广泛增生的场所。亚历山大和相关地体与斯蒂金西缘和其他内侧地体的缝合伴随着广泛的岩浆作用，形成了海岸山脉岩基。然而，岩基内部和附近可能存在北美亲和力的同位素演化物质的存在，引发了关于所有增生地体的异地性程度的基本问题。该项目将尝试确定北美岩石可能的范围、它们与邻近地体的关系以及它们之间的年龄关系。结果将有助于解释缝合带中与增生相关的结构的几何形状，并将提供对斯提金地体的起源和位移历史的约束。