Using accessory minerals of probes of crustal processes

利用地壳过程探针的副矿物

• 批准号: 330836-2009
• 负责人: Hanchar, John
• 金额: $ 3.41万
• 依托单位: Memorial University of Newfoundland
• 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=515068
• 关键词: Using; accessory; minerals; probes; crustal

The objective of my research program over the next five years (and leading to the longer term ten-year time frame) is to gain a better understanding of the Earth's crustal processes recorded through chemical and isotopic variations in accessory minerals such as zircon, monazite, apatite, and titanite. To work towards that goal, I will utilize results obtained by doing in situ tracer radiogenic isotope measurements, including Lu-Hf in zircon and Sm-Nd in monazite, apatite, and titanite; the trace element compositions of those minerals; and U-Th-Pb geochronology. This comprehensive suite of complimentary geo-analytical techniques will be effectively and efficiently used to address a wide range of diverse geologic problems that collectively were not possible until recently. By studying the mineral-scale processes that have controlled the chemical and isotopic changes in the Earth's crust, we can help with the development of a more robust model for the evolution of the crust over time. As part of the Lu-Hf and Sm-Nd research, synthetic minerals will be grown at high-T, doped with elements and specific isotopes of elements, and then chemically and structurally characterized. These crystals will be used as isotopic standards for Hf in zircon and Nd in monazite, titanite, and apatite for radiogenic tracer isotope studies. The synthetic standards will then be used to obtain more precise and accurate in situ analyses of natural minerals using laser ablation multi collector inductively coupled plasma mass spectrometry. One area to be investigated over the next five years includes the granite-lower crustal xenolith connection using Mesozoic lower crustal xenoliths and granites from the Mojave Desert in SE California. This locality is ideal for studying the granite-source connection, as the source region and possibly related anatectic melts can be directly sampled. The source region of post-Alpine tonalites and related rocks from the Adamello batholith in northern Italy will also be studied as part of a larger collaborative research effort with colleagues in Switzerland. The third focus area will address the origin of iron ore, copper, gold (IOCG) and iron ore apatite (IOA) ore deposits and related rocks from the Norrbotten region (e.g., Kiruna) in northern Sweden.

我的研究计划在未来五年（并导致更长期的十年时间框架）的目标是更好地了解通过锆石、独居石、磷灰石和钛矿。 为了实现这一目标，我将利用通过原位示踪放射性同位素测量获得的结果，包括锆石中的 Lu-Hf 以及独居石、磷灰石和钛矿中的 Sm-Nd；这些矿物质的微量元素成分；和 U-Th-Pb 地质年代学。 这套全面的补充地质分析技术将有效且高效地用于解决各种地质问题，而这些问题直到最近才成为可能。 通过研究控制地壳化学和同位素变化的矿物尺度过程，我们可以帮助开发更可靠的地壳随时间演化的模型。 作为 Lu-Hf 和 Sm-Nd 研究的一部分，合成矿物将在高温下生长，掺杂元素和元素的特定同位素，然后进行化学和结构表征。 这些晶体将用作锆石中 Hf 和独居石、钛矿和磷灰石中 Nd 的同位素标准品，用于放射性示踪同位素研究。 然后，合成标准品将用于使用激光烧蚀多收集器电感耦合等离子体质谱法对天然矿物进行更精确和准确的原位分析。 未来五年要研究的一个领域包括使用来自加利福尼亚州东南部莫哈韦沙漠的中生代下地壳捕虏体和花岗岩进行花岗岩与下地壳捕虏体的连接。 该地点非常适合研究花岗岩与源头的联系，因为可以直接对源头区域和可能相关的深熔熔体进行采样。 作为与瑞士同事进行的更大规模合作研究工作的一部分，还将研究意大利北部阿达梅洛岩基的后阿尔卑斯英云闪长岩和相关岩石的源区。 第三个重点领域将解决瑞典北部北博滕地区（例如基律纳）的铁矿石、铜、金（IOCG）和铁矿石磷灰石（IOA）矿床及相关岩石的来源。