RUI: COLLABORATIVE RESEARCH: The Neoproterozoic and Cambrian of the Tethyan Himalaya: A Test of Models of Core Gondwanan Construction

RUI：合作研究：特提斯喜马拉雅的新元古代和寒武纪：冈瓦纳核心构造模型的检验

• 批准号: 9980376
• 负责人: Paul Myrow
• 金额: $ 11.5万
• 依托单位: Colorado College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9980376&HistoricalAwards=false
• 关键词: RUI; COLLABORATIVE; RESEARCH; Neoproterozoic; Cambrian

EAR 9980376 MyrowEAR 9980426 HughesCollaborative Research: THE NEOPROTEROZOIC AND CAMBRIAN OF THE TETHYAN HIMALAYA: A TEST OF MODELS OF CORE GONDWANAN CONSTRUCTIONThe nature and timing of the assembly of core Gondwanaland remains a matterof vigorous debate. The traditional view is that East Gondwana, consistingof India, Australia and Antarctica collided with the combined Africancratons (Kalahari and Congo) as one block sometime during the lateNeoproterozoic. An alternative model suggests that the accretion of EastGondwana to the African craton was a two part process. In this model, Indiabroke off from Australia and Antarctic, swept across the Mozambique Ocean,and collided with the African craton at approximately 680 Ma. This waspurportedly followed sometime later by collision of Australia/Antarcticaaround 550 to 530 Ma. Our study of the Tethyan Himalaya will test tectonicmodels of the assembly of core Gondwanaland using a combined stratigraphic,macrofaunal and sedimentological approach. Of primary importance is thestratigraphic signature of sediment input from adjacent orogenic belts. Arecord of major increases of siliclastic sediment, with abrupt changes inpaleocurrents would accompany orogenesis. A key component of the proposedmodels is that they have predictable patterns of detrital zircon ages. ALate Cambrian-Early Ordovician tectonic event is recorded in the TethyanHimalaya and in other places in East Gondwanaland. The nature of this eventis unclear, but two possibilities include: (1) it represents a somewhatdelayed expression of the Australia/Antarctica collision in the two-stagemodel, or (2) it represents the docking of an outboard microcontinent(e.g., the Lhasa Block of Tibet) subsequent to the formation of coreGondwanaland. The biostratigraphic patterns of trilobites provide the basisof testable predictions of these hypotheses. In the first case, we expectto find a stratigraphic increase in similarity in faunas between India andthe rest of East Antarctica throughout the Cambrian. If faunal similaritywith the rest of East Gondwana was constant throughout thetrilobite-bearing Cambrian, we may infer that Gondwanan construction wascomplete prior to 520 Ma. In addition, if the ~500 Ma tectonic event in theTethyan Himalaya records microcontinental collision, then theidentification of the outboard terrane may be approached throughbiogeographic patterns established in this study. Myrow's RUI proposal willinvolve undergraduates at Colorado College as junior collaborators in allcomponents of the research. This will provide a much-needed opportunity forstudents to experience scientific research in diverse geographical andcultural environments. A key aspect of this proposal is the close researchcollaboration with Indian and Chinese scientists.

合作研究：特提斯-喜马拉雅的新元古代和寒武纪：冈瓦纳地核构造模型的检验冈瓦纳地核组装的性质和时间仍然是一个激烈争论的问题。传统观点认为，在晚新元古代的某个时候，由印度、澳大利亚和南极洲组成的东冈瓦纳与合并的非洲大陆（喀拉哈里和刚果）碰撞成一个板块。另一种模型表明，东冈瓦纳大陆向非洲克拉通的增生是一个分两部分的过程。在这个模型中，印度板块从澳大利亚和南极板块分离出来，横扫莫桑比克海洋，并在大约680 Ma时与非洲克拉通碰撞。据称，随后在550到530 Ma之间，澳大利亚和南极洲发生了碰撞。我们对特提斯喜马拉雅的研究将使用地层学、大型动物学和沉积学相结合的方法来测试冈瓦纳大陆核心组合的构造模型。最重要的是来自相邻造山带的沉积物的地层特征。伴随造山作用的是大量增加的硅质沉积物，以及古洋流的突变。所提出的模型的一个关键组成部分是它们具有可预测的碎屑锆石年龄模式。在特提扬-喜马拉雅地区和东冈瓦纳地区的其他地区记录了晚寒武世-早奥陶世构造事件。这一事件的性质尚不清楚，但有两种可能性：(1)它代表了澳大利亚/南极洲碰撞在两阶段模型中的某种延迟表达，或者(2)它代表了一个外部微大陆的对接(例如；三叶虫的生物地层模式为这些假设提供了可检验的预测基础。在第一种情况下，我们预计在整个寒武纪，印度和东南极洲其他地区之间的动物群相似性会在地层上有所增加。如果在整个有三叶虫的寒武纪，冈瓦纳与东冈瓦纳其他地区的动物群相似性是恒定的，我们可以推断冈瓦纳的构造在520 Ma之前就完成了。此外，如果特提斯-喜马拉雅地区~500 Ma构造事件记录了微大陆碰撞，则可以通过本研究建立的生物地理模式来探讨外部地体的识别。Myrow的RUI提案将让科罗拉多学院的本科生作为初级合作者参与研究的所有组成部分。这将为学生提供一个在不同的地理和文化环境中体验科学研究的急需机会。这项提议的一个关键方面是与印度和中国科学家进行密切的研究合作。