Building India: Clues from the Singhbhum Craton & Southern India

建设印度：辛格布姆克拉通的线索

• 批准号: 1347942
• 负责人: Joseph Meert
• 金额: $ 23万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1347942&HistoricalAwards=false
• 关键词: Building; India; Clues; Singhbhum; Craton

This award is focused on understanding the geological history of the Indian subcontinent and the complexities of its formation. Like many continents, India is composed of several geographically and geologically distinct elements that were welded together to form modern-day Peninsular India. The principal investigators for this project are examining two regions in India that are poorly studied (Singhbhum craton-northeast India and the southern Indian Dharwar craton and surrounding region). The project involves a combination of paleomagnetic and geochronologic studies that provide us with information regarding where and when these continental blocks were incorporated into India along with their relationship to other landmasses during the Proterozoic Eon (2.5 billion to 540 million years ago). It is hypothesized that the Indian subcontinent or some of its sub-regions may have been part of two ancient supercontinents called Rodinia and Columbia. This research is aimed at deciphering the complexities of how these supercontinents were assembled and subsequently dispersed due to plate tectonics, as well as examining any potential links to concomitant changes in the biosphere and climate. This project will provide key information regarding the timing and location of the suture/rift zones between continental blocks within India and the larger landmasses of Columbia and Rodinia. The work involves an international team of scientists from the United States, India, and Canada. In addition to the research objectives of the project, the award is supporting the training of undergraduate and graduate graduate students in a STEM discipline. The principal investigators are working to broaden participation of underrepresented groups in STEM by recruiting students from under-represented groups in the Geosciences. The research results from this project will be disseminated through top journals, meetings, presentations at K-12 educational institutions and other public outreach efforts. Our knowledge of Proterozoic supercontinents such as Rodinia and Columbia are based on a relatively small (but growing) paleomagnetic database. East Gondwana (Australia, Antarctica, India, Madagascar and Sri Lanka) is a critical piece of the supercontinental models. Only India and Australia contain rocks that are relatively un-deformed and un-metamorphosed considered useful for paleomagnetic studies. Our goal in this proposal is to fill in critical gaps in India's drift history through the combined use of paleomagnetism and geochronology. The results are providing researchers with key tie points in reconstructing past continental assemblies. These reconstructions, in turn, will be evaluated for their effects on global climate change, evolution, mantle dynamics and mineral exploration. The key focus of this proposal is to obtain high-quality paleomagnetic data from a series of dykes in the Singhbhum craton and localities in southern India. These data will include geochronological data and field tests to fully constrain the age of magnetization in the rocks. The methodologies employed in this proposal have already proven effective in improving our knowledge of India?s relationship to other landmasses. This proposal will obtain well-dated paleomagnetic poles from the Singhbhum craton (east-central India) and the southernmost Dharwar craton (south India) in an effort to: (a) expand the Proterozoic paleomagnetic and geochronological database for India (its barcode); (b) use paleomagnetism to test cratonic coherence between the north and south Indian cratons across the Central Indian Tectonic zone during the Proterozoic; (c) establish the extent of a proposed ~1.9 Ga radiating dyke swarm already established in the Bastar and Dharwar cratons and (d) establish the position of India in the supercontinents of Rodinia and Columbia. These ideas will be tested by collecting paleomagnetic and geochronologic samples from the targeted regions within India.

该奖项的重点是了解印度次大陆的地质历史及其形成的复杂性。 与许多大陆一样，印度由几个地理和地质上不同的元素组成，这些元素焊接在一起形成了现代的印度半岛。 该项目的主要研究人员正在研究印度两个研究较少的地区（印度东北部的辛布胡姆克拉通和印度南部的达尔瓦尔克拉通及周边地区）。 该项目结合了古地磁和地质年代学研究，为我们提供了有关这些大陆块何时何地并入印度的信息，以及它们在元古代（25 亿至 5.4 亿年前）期间与其他陆地的关系。 据推测，印度次大陆或其一些次区域可能是两个古代超级大陆罗迪尼亚和哥伦比亚的一部分。 这项研究旨在破译这些超级大陆如何因板块构造而聚集和随后分散的复杂性，并检查与生物圈和气候的伴随变化的任何潜在联系。该项目将提供有关印度境内大陆块与哥伦比亚和罗迪尼亚较大陆地之间缝合/裂谷带的时间和位置的关键信息。 这项工作涉及来自美国、印度和加拿大的国际科学家团队。 除了该项目的研究目标外，该奖项还支持 STEM 学科本科生和研究生的培训。主要研究人员正在努力通过招募来自地球科学领域代表性不足群体的学生来扩大 STEM 中代表性不足群体的参与。 该项目的研究成果将通过顶级期刊、会议、K-12 教育机构的演讲以及其他公共宣传活动进行传播。 我们对罗迪尼亚和哥伦比亚等元古代超大陆的了解是基于相对较小（但不断增长）的古地磁数据库。东冈瓦纳大陆（澳大利亚、南极洲、印度、马达加斯加和斯里兰卡）是超大陆模型的关键部分。只有印度和澳大利亚含有相对未变形和未变质的岩石，被认为对古地磁研究有用。我们这项提案的目标是通过结合使用古地磁学和地质年代学来填补印度漂移历史的关键空白。研究结果为研究人员提供了重建过去大陆议会的关键联系点。反过来，这些重建将评估其对全球气候变化、演化、地幔动力学和矿物勘探的影响。该提案的重点是从 Singhbhum 克拉通和印度南部地区的一系列岩堤获取高质量的古地磁数据。这些数据将包括地质年代学数据和现场测试，以充分限制岩石中磁化的年龄。事实证明，该提案中采用的方法可以有效提高我们对印度与其他大陆关系的了解。该提案将从 Singhbhum 克拉通（印度中东部）和最南端的 Dharwar 克拉通（印度南部）获取年代明确的古地磁极，以期： (a) 扩大印度元古代古地磁和地质年代学数据库（其条形码）； (b) 利用古地磁学来测试元古宙横跨中印度构造带的北印度克拉通和南印度克拉通之间的克拉通一致性； (c) 确定已在巴斯塔和达尔瓦尔克拉通建立的拟议~1.9 Ga 辐射堤群的范围，以及 (d) 确定印度在罗迪尼亚和哥伦比亚超级大陆中的位置。这些想法将通过从印度境内目标地区收集古地磁和地质年代学样本来检验。