Collaborative Research: Permian-Triassic Basin History of Southern Victoria Land and the Darwin Mountains

合作研究：维多利亚州南部土地和达尔文山脉的二叠纪-三叠纪盆地历史

• 批准号: 9909749
• 负责人: Rosemary Askin
• 金额: $ 22.05万
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 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 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9909749&HistoricalAwards=false
• 关键词: Collaborative; Research; Permian; Triassic; Basin

9909749AskinThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative sedimentological, palynological, and paleomagnetic study of Permian and Lower Triassic strata in southern Victoria Land (SVL) and the Darwin Mountains (DM), Antarctica. Results of the study will help constrain the paleoenvironmental, tectonic, biotic, and paleogeographic histories of southern Pangea and provide a unique polar view of the world during an icehouse to greenhouse transition.The assembly and drift of Pangea resulted in heightened orogenic activity and associated development of numerous depositional basins. One of the largest basins was the 10,000+ km long "Gondwanide foredeep" that extended across southern South America, South Africa, the Falkland Islands, Antarctica, and Australia. Antarctica's centralized location between South Africa and Australia, make SVL and DM key areas for testing paleogeographic and paleoclimatic models.Upper Paleozoic and Lower Mesozoic rocks in SVL and DM were deposited during Gondwanaland's drift across the south pole. Based on present plate reconstructions, SVL and DM were located higher than 75 degrees south latitude from 320 to 210 Ma. Despite the putative high latitude position, SVL and DM sedimentary successions record a change from Lower Permian glacial deposits, to Permian fluvial coal measures, to Lower Triassic non-carbonaceous fluvial deposits, and finally to Middle and Upper Triassic fluvial coal measures, with well-developed vegetation during much of this time. Present climatic simulations suggest seasonal climatic extremes within Pangea's polar interior. Discrepancies between the geological evidence and the climate simulations need to be resolved, and may be magnified by incomplete understanding of the influence of paleotopography, large lakes, and river systems at the time of deposition, as well as by incomplete documentation of paleoenvironmental conditions. Furthermore, Late Permian and Triassic mean pole positions for Gondwanaland are not tightly constrained. Paleomagnetic signatures will be recovered from Permian and Triassic petrified wood, silicified peat, and coal, which were cemented during early diagenesis (preliminary results indicate stable remnant magnetizations). Palynological analyses will provide time control for the succession.Objectives of this study include:1) Determination of a late Paleozoic glacial/deglaciation history for SVL and DM as Gondwana drifted over the south pole,2) Documentation of Permian strata as a means to better understand the environments of high latitude fluvial coal-bearing deposits,3) Documentation of Triassic lithofacies as a means to better understand high latitude conditions during the Early to Middle Triassic "coal gap" interval,4) Providing a well-constrained stratigraphic framework for the Permian to lower Triassic succession,5) Testing the diachronous and inversion tectonic models for the Panthalassan Margin of southwestern Pangea, and6) Constructing better paleogeographic models for Gondwana by obtaining new Gondwana reference poles for the Permian and Triassic.

9909749SaskInthis奖，由极地计划办公室的南极地质与地球物理学计划提供，支持了维多利亚州南部（SVL）和Darwin Mountains（DM）的二叠纪和下三叠纪地层的协作沉积学，孢粉学和古磁研究。该研究的结果将有助于限制南方南方南部的古环境，构造，生物和古地理历史，并在冰屋向温室过渡期间提供世界的独特极地景观。pangea的组装和漂移导致造山学活性增强，并增强了许多沉积层的发展。最大的盆地之一是长10,000公里长的“冈旺德河”（Gondwanide Foredeep），该盆地延伸到南美南美洲，南非，福克兰群岛，南极洲和澳大利亚。南极洲在南非和澳大利亚之间的集中位置，使SVL和DM关键区域用于测试古地理和古气候模型。在冈瓦纳兰（Gondwanaland）越过南极的漂移期间，SVL和DM中的古生代和下层岩石被沉积。基于目前的板重建，SVL和DM的位置高于320至210 mA的南纬75度。尽管有推定的高纬度位置，但SVL和DM沉积继承序列记录了从下二叠纪冰川沉积物，二叠纪河流煤的测量，降低三叠纪的非碳质河流沉积物，最后到中期和上层三叠纪的河流煤层，并在这段时间内具有良好的植被。目前的气候模拟表明，Pangea极地内部的季节性气候极端。需要解决地质证据与气候模拟之间的差异，并且可能会因对古代形象，大湖泊和河流系统的影响以及古环境条件的不完整记录而放大。此外，冈瓦纳兰德的晚期和三叠纪平均极位置并未受到严格的约束。将从二叠纪和三叠纪石化的木材，硅化泥炭和煤中回收古磁特征，这些泥炭和煤是在早期成岩作用期间粘附的（初步结果表明稳定的残余磁化）。 Palynological analyses will provide time control for the succession.Objectives of this study include:1) Determination of a late Paleozoic glacial/deglaciation history for SVL and DM as Gondwana drifted over the south pole,2) Documentation of Permian strata as a means to better understand the environments of high latitude fluvial coal-bearing deposits,3) Documentation of Triassic lithofacies as a means to better understand high latitude conditions在三叠纪早期的“煤层”间隔期间，4）为二叠纪提供一个较低的地层框架，以降低三叠纪继任的速度，5）测试西南pangea的泛统边缘的期权和反转构造模型，为西南pangea和6）构建更好的古地理模型，并通过新地理模型来构建新的gondiassic and gondiase gondwana and gondiase gondwana，以预言新的gondwana，以预言gondwana。