Investigating the tectonic evolution of the canadian cordillera through structural, metamorphic and multifaceted geochronologic studies

通过结构、变质和多方面的地质年代学研究研究加拿大山脉的构造演化

• 批准号: 312461-2008
• 负责人: Gibson, Daniel
• 金额: $ 2.18万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=457435
• 关键词: Investigating; tectonic; evolution; canadian; cordillera

The collision of continents, microcontinents, and island arcs at subduction zone boundaries is a fundamental mountain building process (i.e. orogenesis). The resultant geology of these mountain belts (orogens) includes a complex superposition of deformation and metamorphic events. My proposed research will focus upon investigating these interrelated tectonic processes associated with collisional orogens. In the Canadian Cordillera, my graduate students I and will continue to carry out a program of geologic mapping accompanied by microscope analysis in the lab of the structural and metamorphic elements. Another component of this research will include determination of precise timing constraints (geochronology) that are crucial for reconstructing the geologic history and developing tectonic models. Once the geologic relationships are rigorously determined via field-based mapping and microscope analysis, uranium (U) and lead (Pb) isotopes of radiogenic minerals (e.g. zircon, monazite) will be analyzed using a variety of geochronologic techniques. These include Isotope Dilution-Thermal Ionization Mass Spectrometry (ID-TIMS) and in situ analysis of minerals in thin section and grain mount using ion and electron microprobes and Laser Ablation-Inductively Coupled Mass Spectrometry (LA-ICPMS). My integrated approach to field geology and geochronology has proven to be very effective. I have provided highly precise and accurate age constraints for tectonic processes in the southern Canadian Cordillera, and have elucidated some of the complex crystal-chemical processes that plague radiometric minerals used for U-Pb geochronology. It is anticipated that the proposed research will refine our current understanding of tectonic processes associated with collisional orogens, and more specifically, the amalgamation and sculpting of the continental crust underlying the Canadian Cordillera.

俯冲带边界处的大陆，微型内部和岛屿弧的碰撞是一个基本的山区建筑过程（即造山学）。这些山带（Orogens）的最终地质包括变形和变质事件的复杂叠加。我拟议的研究将重点是研究与碰撞orgens相关的这些相互关联的构造过程。在加拿大柯迪拉拉（Condillera），我的研究生I和将继续在结构和变质元素的实验室中进行一项地质映射程序，并进行显微镜分析。这项研究的另一个组成部分将包括确定精确的时序限制（地质学），这些定时限制（地质学）对于重建地质历史和开发构造模型至关重要。一旦通过基于田间的映射和显微镜分析来严格确定地质关系，铀（U）和铅（Pb）同位素将使用各种地球体学技术分析放射性矿物的（例如锆石，独居石）。这些包括使用离子和电子微探针以及激光消融式耦合的质谱法（LA-ICPMS），包括同位素稀释 - 热电离质谱法（ID-TIMS）和薄截面和谷物架的矿物的原位分析。事实证明，我对现场地质和地质学的综合方法非常有效。我为加拿大南部Cordillera的构造过程提供了高度精确和准确的年龄限制，并阐明了一些复杂的晶体化学过程，这些过程损害了用于U-PB地质学用于U-PB的射频辐射矿物质。预计拟议的研究将完善我们目前对与碰撞orgens相关的构造过程的理解，更具体地说，是加拿大山脉底层的大陆壳的合并和雕刻。