The Effects of Paleolatitude and Precipitation Gradients on Triassic Palynofloral Diversity

古纬度和降水梯度对三叠纪孢粉植物多样性的影响

• 批准号: 9418464
• 负责人: Sarah Fowell
• 金额: $ 16.5万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-06-01 至 1997-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9418464&HistoricalAwards=false
• 关键词: Effects; Paleolatitude; Precipitation; Gradients; Triassic

Fowell 9418464 Climatic extremes have been suggested as the cause of high extinction rates among Late Triassic organisms, but the impact of warm global temperatures and climate change on the diversity of these fossil groups has not been examined in detail. Analysis of palynofloral data from continuous cores and correlative outcrops of the Triassic Newark Supergroup is proposed in order to separate the effects of paleolatitude, precipitation gradients, and evolutionary changes on palynofloral composition. The magnetic reversal stratigraphy and cyclostratigraphy of Newark basin cores provides a framework of rigorous temporal and geographic control for the Newark Supergroup and permits high-resolution correlation between separate but tectonically similar basins. Collection and comparison of coeval palynofloras from four time slices in cores of the Newark and Taylorsville basins and outcrops of the Culpeper and Fundy basins is planned in order to reconstruct Late Triassic palynofloral diversity gradients across 7o of paleoaltitude from an equatorial humid belt to a sub-equatorial arid zone. Species counts from these assemblages will be used to delineate Triassic vegetational communities, while similarity coefficients and polar ordination will be employed to determine how these communities changed over time and paleolatitude. Isolation of the climatic/geographic and temporal aspects of floral composition and diversity will permit evaluation of the various climate-driven extinction scenarios and provide a useful test of Triassic climate models.

Fowell 9418464 极端气候被认为是晚三叠世生物高灭绝率的原因，但全球变暖和气候变化对这些化石群多样性的影响尚未得到详细研究。 分析孢粉植物区系的数据从连续的核心和相关的露头的三叠纪纽瓦克超群的建议，以分离的影响，古纬度，降水梯度和演化变化的孢粉植物组成。 纽瓦克盆地岩心的磁反转地层学和旋回地层学为纽瓦克超群提供了严格的时间和地理控制框架，并允许在独立但构造相似的盆地之间进行高分辨率对比。 收集和比较从四个时间切片的核心的纽瓦克和泰勒斯维尔盆地和露头的库尔佩珀和芬迪盆地的同生孢粉植物群的计划，以重建晚三叠世孢粉植物多样性梯度跨越7 °的古海拔从赤道潮湿带亚赤道干旱带。 从这些组合的物种计数将被用来描绘三叠纪植被群落，而相似系数和极地排序将被用来确定这些社区如何随着时间和古纬度的变化。 隔离的气候/地理和时间方面的植物组成和多样性将允许评估各种气候驱动的灭绝的情况下，并提供了一个有用的测试三叠纪气候模型。