Incredible India: High Resolution Proterozoic Paleogeography through integrated studies of mafic dykes

不可思议的印度：通过镁铁质岩脉综合研究进行高分辨率元古代古地理

• 批准号: 1850693
• 负责人: Joseph Meert
• 金额: $ 28.72万
• 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: 2019
• 资助国家: 美国
• 起止时间: 2019-03-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1850693&HistoricalAwards=false
• 关键词: Incredible; India; Resolution; Proterozoic; Paleogeography

The motion of continental crust over long periods of Earth history results in the periodic assembly of larger landmasses referred to as supercontinents. The most recent supercontinent, Pangea, coalesced about 300 million years ago, whereas older supercontinents are hypothesized to have formed around 600 million years ago (Pannotia), 1000 million years ago (Rodinia), and 1800 million years ago (Columbia/Nuna). Supercontinents have a coincident relationship to some important developments in Earth history including the formation of economic mineral deposits (Columbia), severe climatic fluctuations (Rodinia) and the evolution of modern animal phyla (Pannotia). Because modern continents hold the dispersed remnants of ancient crust, determining the timing of supercontinent assembly requires paleomagnetic and geochronologic knowledge of the entire globe. Peninsular India is a fusion of five ancient pieces of continental crust known as the Aravalli, Bundelkhand, Singhbhum, Dharwar, and Bastar cratons. The research in this proposal is focused on determining the paleogeographic assembly of the five cratonic pieces by an investigation into the magnetic directions in igneous rocks. The diverse research team, including undergraduate students, graduate students and foreign collaborators, targets three key regions in the Dharwar, Bundelkhand and Singhbhum cratons. The paleomagnetic data being gathered in this investigation is incorporated into global paleogeographic models that are key to understanding larger scale questions such as: When were all continents assembled into larger supercontinents?, How has the Earth's magnetic field changed through time?, and What were ancient climatic conditions and how might they help us understand future climates?. Important societal impacts from this study include the training of graduate and undergraduate students in an important STEM discipline, educational outreach activities and collaboration with a 2-year community college, K-12 classroom outreach including predominantly African-American and Hispanic middle schools, and efforts that involve mentorship of university STEM students from underrepresented groups. The project also involves international scientific collaboration with scientists from India.The investigators outline a series of goals aimed to clarify the geological history of Peninsular India and interpret global tectonic implications. The work conducted in this proposal is generating that 1) refine the sequence of events that led to India's assembly, and 2) also elucidate India's place in the proposed supercontinents of Columbia/Nuna and Rodinia. In a review of global tectonic models, it is noted that Peninsular India is treated as a unified block during the entire Proterozoic, but available paleomagnetic and geochronologic data do not support such a conclusion. Additionally, structural and geochronological data from the Central Indian Tectonic Zone suggest that unity was not achieved until ~1100-900 Ma. Comparing a robust paleomagnetic record from India with results from around the globe will establish the tempo and mode of plate tectonics in the Proterozoic, helping answer the question of when modern style tectonics began. In reviewing "traditional" models of Rodinia and Columbia, it is apparent that the central structure of the supercontinents appears to show little change. If the Rodinia configuration represents only a slight variation on Columbia/Nuna, this might reflect some underlying difference from modern-style (Phanerozoic) plate tectonics, or perhaps fundamental mode of plate organization regularity throughout geologic time. These data allow the researchers to evaluate potential "nearest neighbors" to the Indian cratons such as North China, East Antarctica, Australia, Baltica, and parts of Africa and Madagascar. The contributions add an important component to studies of ancient climatic gradients across the Earth, behavior and strength of the magnetic field, the record of true polar wander, and the identification of large igneous provinces in formerly adjacent cratons that may host important metallogenic ore deposits.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在地球历史的很长一段时期内，大陆地壳的运动导致了被称为超大陆的较大大陆的周期性组装。最近的超级大陆，盘古大陆，大约在3亿年前融合在一起，而更古老的超级大陆被假设形成于大约6亿年前(潘诺提纳)、1000亿年前(罗迪尼亚)和1.8亿年前(哥伦比亚/努纳)。超大陆与地球历史上的一些重要发展有着一致的关系，包括经济矿藏的形成(哥伦比亚)、严重的气候波动(Rodinia)和现代动物门(Pannua)的演化。由于现代大陆拥有分散的古代地壳残骸，确定超级大陆组装的时间需要整个地球的古地磁和地质年代学知识。印度半岛是由五块古老的大陆地壳融合而成的，它们分别是阿拉瓦利、邦德尔汉德、辛格布胡姆、达瓦尔和巴斯塔克拉通。这项建议的研究重点是通过对火成岩中的磁性方向的调查来确定五个克拉通板块的古地理组合。这个多元化的研究团队包括本科生、研究生和外国合作者，目标是达瓦尔、邦德尔坎德省和辛格洪姆克拉通的三个关键地区。在这次调查中收集的古地磁数据被纳入全球古地理模型，这些模型是理解更大规模问题的关键，例如：所有大陆何时组装成更大的超级大陆？地球磁场随时间发生了怎样的变化？古代气候条件是什么？它们如何帮助我们理解未来的气候？这项研究产生的重要社会影响包括在一个重要的STEM学科对研究生和本科生的培训、教育推广活动以及与一所两年制社区学院的合作、包括主要由非洲裔美国人和西班牙裔美国人组成的中学的K-12课堂推广活动，以及涉及指导来自代表性不足群体的大学STEM学生的努力。该项目还涉及与印度科学家的国际科学合作。调查人员概述了一系列目标，旨在澄清印度半岛的地质历史，并解释全球构造含义。在这项提案中开展的工作产生了：1)完善了导致印度大会的事件顺序，2)还阐明了印度在拟议的哥伦比亚/努纳和罗迪尼亚超级大陆中的地位。在对全球构造模型的回顾中，人们注意到印度半岛在整个元古界被视为一个统一的地块，但现有的古地磁和地质年代学数据不支持这一结论。此外，来自中印度构造带的构造和地质年代学数据表明，直到约1100-900 Ma才实现统一。将印度强劲的古地磁记录与世界各地的结果进行比较，将建立元古界板块构造的速度和模式，有助于回答现代风格构造开始的时间问题。回顾罗迪尼亚和哥伦比亚的“传统”模型，很明显，超级大陆的中心结构似乎没有什么变化。如果Rodinia构型仅仅代表了哥伦比亚/努纳的微小变化，这可能反映了与现代(显生界)板块构造的一些潜在差异，或者可能反映了整个地质时代板块组织规则的基本模式。这些数据使研究人员能够评估潜在的印度克拉通“近邻”，如北中国、东南极、澳大利亚、波罗的海、非洲部分地区和马达加斯加。这些贡献为研究地球上的古代气候梯度、磁场的行为和强度、真正的极地漂移记录，以及在以前相邻的克拉通中识别可能拥有重要成矿矿床的大型火成岩省份增加了重要的组成部分。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Stinging News: ‘Dickinsonia’ discovered in the Upper Vindhyan of India Not Worth the Buzz

• DOI: 10.1016/j.gr.2023.01.003
• 发表时间: 2023-01
• 期刊: Gondwana Research
• 影响因子: 6.1
• 作者: J. Meert;M. Pandit;S. Kwafo;A. Singha

The Columbia supercontinent: Retrospective, status, and a statistical assessment of paleomagnetic poles used in reconstructions

• DOI: 10.1016/j.gr.2022.06.014
• 发表时间: 2022-06
• 期刊: Gondwana Research
• 影响因子: 6.1
• 作者: J. Meert;M. Santosh

Reply to the comment by Retallack et al. (2023) on “Stinging News: ‘Dickinsonia’ discovered in the Upper Vindhyan of India not worth the buzz”

回复 Retallack 等人的评论。

• DOI: 10.1016/j.gr.2023.02.016
• 发表时间: 2023
• 期刊: Gondwana Research
• 影响因子: 6.1
• 作者: Kwafo, Samuel;Singha, Ananya;Pandit, Manoj;Meert, Joseph
• 通讯作者: Meert, Joseph

Paleomagnetic results from the Singhbhum Craton, India: Remagnetization, demagnetization, and complication

印度 Singhbhum 克拉通的古地磁结果：重磁化、退磁和复杂化

• DOI: 10.1016/j.precamres.2021.106165
• 发表时间: 2021
• 期刊: Precambrian Research
• 影响因子: 3.8
• 作者: Pivarunas, Anthony F.;Meert, Joseph G.;Katusin, Karastin D.;Pandit, Manoj K.;Miller, Scott R.;Craver, Aubrey;Roderus, Kelli M.;Sinha, Anup
• 通讯作者: Sinha, Anup

Intracratonic stability: A comparison of paleomagnetic data from the north and the south of Dharwar Craton, India

• DOI: 10.1016/j.precamres.2020.105858
• 发表时间: 2020-07
• 期刊: Precambrian Research
• 影响因子: 3.8
• 作者: A. Pivarunas;J. Meert