Collaborative Research: Origin and Significance of High Potassium Volcanism: Insights from the Ancestral Cascades, California

合作研究：高钾火山活动的起源和意义：来自加利福尼亚州祖先瀑布的见解

• 批准号: 0711150
• 负责人: Keith Putirka
• 金额: $ 15.78万
• 依托单位: California State University-Fresno Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0711150&HistoricalAwards=false
• 关键词: Collaborative; Research; Origin; Significance; Potassium

One of the major scientific questions regarding the geologic history of the western U.S. is to identify exactly when faulting and uplift began in the Sierra Nevada. This timing is crucial because it impacts our understanding of strain rates on particular faults, and hence has an impact on seismic hazards. The issue is also important since such uplift coincides with the birth of a plate boundary-the boundary between the Great Basin and the Sierra microplate. Volcanic activity has long been known to be associated with changes to the plate boundary activity. In this project, the collaborative team will examine the nature of high potassium volcanism in the Sierra Nevada as a potential signal of the birth of this new plate boundary.High potassium volcanism has long been looked to as an indicator of tectonic activity, but its origin remains unclear. Preliminary field and geochemical data show the existence of an ancestral Cascades arc in the central Sierra Nevada and eastern California, and a potential link between the inception of a plate boundary and the magmatism that led to a series of high K eruptions. For that reason, the central Sierra region provides an ideal place to study the geochemistry of high potassium magmatic rocks and the possibility that this unusual magmatism is a reflection of the delamination and uplift of the Sierra Nevada. The research proposed will provide an important and much-needed geologic and geochronologic framework for petrologic study of high-K rocks of the ancestral Cascades arc and enable to researchers to evaluate three petrologic-tectonic models for the origin of high potassium volcanism. This project establishes a research linkage between the University of California-Santa Barbara (UCSB) and California State University-Fresno (CSU Fresno) that will allow students from CSU Fresno to have the invaluable experience of working closely with faculty and graduate students at a research-oriented institution. CSU Fresno is an RUI institution that has been designated Hispanic serving; women currently comprise 60% of the students in the CSU Fresno Geology Department, and half of the incoming students in 2006 are female and Hispanic. This represents a significant shift in the demographics of the population of Geology majors, and it is crucial that these students are able to become involved in RUI projects. Dr. Cathy Busby provides an invaluable mentor to female students at both CSU Fresno and UCSB, and a role model for young women at both institutions. The student support sought in this proposal also is crucial to CSU Fresno as a recruitment tool to bring students into Geology.

关于美国西部地质历史的主要科学问题之一是准确确定内华达山脉断层和隆起开始的时间。 这个时机至关重要，因为它会影响我们对特定断层应变率的理解，从而对地震灾害产生影响。这个问题也很重要，因为这种隆起恰逢板块边界的诞生，即大盆地和内华达微板块之间的边界。人们早就知道火山活动与板块边界活动的变化有关。在这个项目中，合作团队将研究内华达山脉高钾火山活动的性质，将其作为这个新板块边界诞生的潜在信号。高钾火山活动长期以来一直被视为构造活动的指标，但它的起源仍不清楚。初步的现场和地球化学数据显示，在内华达山脉中部和加利福尼亚州东部存在着古老的喀斯喀特弧，以及板块边界的开始与导致一系列高钾喷发的岩浆活动之间的潜在联系。因此，中部山脉地区提供了一个理想的场所来研究高钾岩浆岩的地球化学，以及这种不寻常的岩浆活动反映内华达山脉分层和隆起的可能性。拟议的研究将为原始喀斯喀特弧的高钾岩石的岩石学研究提供一个重要且急需的地质和年代学框架，并使研究人员能够评估高钾火山活动起源的三种岩石学构造模型。 该项目在加州大学圣塔芭芭拉分校 (UCSB) 和加州州立大学弗雷斯诺分校 (CSU Fresno) 之间建立了研究联系，使 CSU 弗雷斯诺分校的学生能够获得与教师和研究生密切合作进行研究的宝贵经验导向型机构。 CSU 弗雷斯诺分校是一所 RUI 院校，已被指定为西班牙裔服务；目前，科罗拉多州立大学弗雷斯诺地质系学生中女性占 60%，2006 年新生中有一半是女性和西班牙裔。这代表了地质学专业人口结构的重大转变，这些学生能够参与 RUI 项目至关重要。 Cathy Busby 博士为科罗拉多州立大学弗雷斯诺分校和加州大学圣巴巴拉分校的女学生提供了宝贵的导师，并为两所院校的年轻女性树立了榜样。该提案寻求的学生支持对于科罗拉多州立大学弗雷斯诺分校作为吸引学生进入地质学的招生工具也至关重要。