Petrology and tectonics of the Cordillera

科迪勒拉山脉的岩石学和构造学

• 批准号: 194090-2011
• 负责人: Thorkelson, Derek
• 金额: $ 2.4万
• 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: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=507782
• 关键词: Petrology; tectonics; Cordillera

The mountain belt located along the western edge of North and South America, commonly referred to as the Cordillera, was formed by Earth processes dating back to the Precambrian (older than 550 million years) and continuing to the present day. In the modern environment, these processes are manifested by earthquakes, volcanoes, and the current pattern of geological features. Those that occurred in ancient times are recorded by older rock formations that can be examined in the field and laboratory to interpret the nature, age and sequence of events. This proposal seeks to understand two aspects of Cordilleran geology, one of which refers to modern and geologically recent times, and the other to more ancient times in the Precambrian. The study of modern processes will examine rocks, other geological features, and geophysical characteristics at locations where two tectonic plates located beneath the Pacific ocean are moving apart from one another, and one or both of them is subducting (being pulled beneath) the plates that make up the Americas. The process involved, termed ridge subduction, is occurring at four localities at the present time, including beneath western Canada. Studying the earthquakes, volcanoes and other features that form in these locations will clarify the mechanisms and outcomes of ridge subduction. The study of Precambrian rocks will be carried out on formations in the Yukon and northern British Columbia. The goal is to decipher the ancient geological environment and determine the most likely configuration of the continents the Precambrian. Both the Precambrian and modern investigations involve petrology (the study of rocks, their features and their compositions) and tectonics (the study of Earth structures and movements). The methods to be used in these studies include geological mapping, rock and mineral examination, determination of geochemical compositions and isotopic ages, plus geographical information system (GIS) technology.

位于北美和南美洲西部边缘的山脉带，通常被称为科迪勒拉，是由地球作用形成的，可以追溯到前寒武纪(超过5.5亿年)，一直延续到今天。在现代环境中，这些过程表现为地震、火山和现今地质特征的格局。那些发生在古代的事件是由更古老的岩层记录下来的，可以在野外和实验室进行检查，以解释事件的性质、年龄和顺序。这个建议试图理解科迪勒地质学的两个方面，一个是指现代和地质上的现代，另一个是指前寒武纪的更古老的时代。对现代过程的研究将考察位于太平洋下方的两个构造板块相互分离，其中一个或两个板块正在俯冲(被拉到)构成美洲的板块之下的地点的岩石、其他地质特征和地球物理特征。这一过程被称为海脊俯冲，目前正在包括加拿大西部在内的四个地方发生。研究这些地区形成的地震、火山和其他特征将阐明海脊俯冲的机制和结果。对前寒武纪岩石的研究将在育空地区和不列颠哥伦比亚省北部的地层中进行。目标是破译古代地质环境，并确定最有可能的前寒武纪大陆的形态。前寒武纪和现代研究都涉及岩石学(研究岩石、岩石特征及其成分)和构造学(研究地球结构和运动)。这些研究将使用的方法包括地质填图、岩石和矿物检查、地球化学成分和同位素年龄的测定，以及地理信息系统(GIS)技术。