Collaborative Research: Origin of the Alexander Terrane in the Arctic Realm?

合作研究：北极地区亚历山大地体的起源？

• 批准号: 0948359
• 负责人: William McClelland
• 金额: $ 12.07万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0948359&HistoricalAwards=false
• 关键词: Collaborative; Research; Origin; Alexander; Terrane

This project will test the hypothesis that much of southern Alaska formed along the Arctic margin of Canada, with transport to its present position only in the relatively recent geologic past. Such a displacement history is counter to the more traditional view that these rocks, and most other portions of western North America (e.g., Baja California), have moved northward along the continental margin. It also differs from previous suggestions that these rocks formed along the western margin of the paleo-Pacific and are truly exotic to North America. Fortunately, recent technological developments have provided a technique that will provide a robust evaluation of these possible displacement scenarios. The technique involves the determination of ages of zircon crystals in the displaced rocks and in potential correlatives in the western US, along the western margin of the paleo-Pacific, and in the Canadian Arctic. The occurrence of similar ages would suggest potential linkages, whereas the occurrence of different ages of zircon crystals in rocks of the same age would be inconsistent with geographic proximity. This project will provide opportunities for undergraduate and graduate students at two universities to participate in a research project that involves both field studies in frontier regions and laboratory analyses utilizing sophisticated instrumentation. Primary activities involved in this project will include:1. Conducting geologic field studies and collecting samples from Paleozoic strata of the Alexander terrane in southeast Alaska and the Pearya terrane in the Canadian Arctic. These studies will be based from zodiacs and a live-aboard boat (presently operated by the University of Arizona) in SE Alaska and with helicopter support in the Canadian Arctic.2. Determining U-Pb ages and Hf isotope ratios of detrital zircons utilizing a new Laser Ablation-ICPMS system (Nu HR ICPMS) and SEM system (Hitachi 3400N and Gatan Chroma CL) at the University of Arizona.3. Comparison of our new data with U-Pb ages and Hf isotope information from other assemblages in the circum-Pacific and circum-Arctic realms in an effort to test various possible displacement models for the Alexander terrane. Much of the field and lab research will be conducted by graduate students at the University of Arizona and the University of Iowa. Undergraduate students will be involved as field assistants, with possible senior-thesis-type projects available as appropriate.

该项目将检验以下假设：阿拉斯加南部的大部分地区沿加拿大北极边缘形成，仅在相对较新的地质历史中运输到目前的位置。 这种流离失所的历史与更传统的观点背道而驰，即这些岩石以及北美西部（例如加利福尼亚州巴哈）的大多数部分沿着大陆边缘向北移动。 这也与以前的建议不同，即这些岩石沿着古太平洋的西边边缘形成，对北美确实是异国情调的。 幸运的是，最近的技术发展提供了一种技术，该技术将对这些可能的位移情况进行强有力的评估。 该技术涉及确定流离失所的岩石中锆石晶体的年龄，并在美国西部，沿着古 - 太平洋的西边和加拿大北极地区的潜在相关性确定。 相似年龄的发生将表明潜在的联系，而同一年龄岩石中不同年龄的锆石晶体的发生将与地理接近度不一致。 该项目将为两所大学的本科生和研究生提供机会参加一个研究项目，该项目涉及Frontier地区的现场研究和利用复杂仪器的实验室分析。 该项目涉及的主要活动将包括：1。从阿拉斯加东南部亚历山大·塔雷恩（Alexander Terrane）的古生代地层和加拿大北极的皮尔雅地道进行地质田间研究并收集样品。 这些研究将基于十二生肖和位于阿拉斯加塞拉斯加的活船（目前由亚利桑那大学运营）以及加拿大北极2的直升机支撑。2。利用新的亚利桑那大学（University of Arizona）的新激光消融-ICPMS系统（NU HR ICPMS）（NU HR ICPMS）（NU HR ICPMS）（NU HR ICPMS）（NU HR ICPMS）（NU HR ICPMS）（NU HR ICPMS）（NU HR ICPMS）（Hitachi 3400N和Gatan Chroma CL）确定U-PB年龄和HF同位素比。比较我们的新数据与U-PB年龄和HF同位素信息来自圆周和北极领域中其他组合的HF同位素信息，以测试亚历山大Terrane的各种可能的位移模型。 亚利桑那大学和爱荷华大学的研究生将进行大部分领域和实验室研究。 本科生将作为现场助理参与，并有可能适当的高级论文类型项目。