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

GSTDTAP

项目编号	1850693
	Incredible India: High Resolution Proterozoic Paleogeography through integrated studies of mafic dykes
	Joseph Meert (Principal Investigator)
主持机构	University of Florida
项目开始年	2019
	2019-03-01
项目结束日期	2021-02-28
资助机构	US-NSF
项目类别	Standard Grant
项目经费	287227(USD)
国家	美国
语种	英语
英文摘要	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.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/213160
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Joseph Meert .Incredible India: High Resolution Proterozoic Paleogeography through integrated studies of mafic dykes.2019.