Petrogenesis of the Mt. Jefferson Area, Oregon High Cascades

俄勒冈州杰斐逊山地区高喀斯喀特的岩石成因

• 批准号: 8917349
• 负责人: Peter Hooper
• 金额: --
• 依托单位: Washington State University
• 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: 1990-09-01 至 1992-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8917349&HistoricalAwards=false
• 关键词: Petrogenesis; Mt.; Jefferson; Area; Oregon

Recent mapping and bulk chemical analyses have established the existence of a long-lived field of andesitic and dacitic volcanism in the Mt. Jefferson area of the High Cascade Range in Oregon. The project aims to further constrain the temporal evolution of this volcanic field with precise K-Ar age dating, and to better understand the petrogenesis of the filed with rare earth element (REE) and isotopic (O, Sr, and Nd) analyses. The volcanic field around Mt. Jefferson is particularly suitable for this study as it has been mapped in detail over a period of five years, and an extensive and detailed stratigraphic framework involving some 150 map units has been established. Few parts of arcs anywhere are known in such detail. An extensive bulk composition and electron microprobe data base has also been acquired on the Mt. Jefferson area rocks. These data demonstrate the importance of open system processes, presumably magma mixing, in these rocks. this conclusion applies to all rock types examined, including basaltic andesites, andesites, and dactites.

最近的绘图和大量的化学分析已经建立了一个长期存在的安山和英安岩火山作用的山。位于俄勒冈州的高喀斯喀特山脉的杰斐逊地区。该项目旨在通过精确的K-Ar年龄测定进一步限制该火山岩场的时间演化，并通过稀土元素（REE）和同位素（O，Sr和Nd）分析更好地了解该火山岩场的岩石成因。山周围的火山区。杰斐逊是特别适合这项研究，因为它已经详细绘制了五年的时间，并建立了广泛而详细的地层框架，涉及约150个地图单位。很少有地方的弧部分是如此详细地知道的。一个广泛的散装成分和电子探针数据库也已获得的山。杰佛逊区岩石。这些数据表明，开放系统的过程，可能是岩浆混合，在这些岩石的重要性。这一结论适用于所研究的所有岩石类型，包括玄武安山岩、安山岩和英安岩。