Stratigraphy, Sedimentology, Paleontology and Provenance of the Uppermost Gazelle Formation (Devonian), Northern California

北加州最上部瞪羚组（泥盆纪）的地层学、沉积学、古生物学和起源

基本信息

批准号：
8916161
负责人：
Timothy Wallin
金额：
$ 7.4万
依托单位：
University of Nevada Las Vegas
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
1990
资助国家：
美国
起止时间：
1990-04-01 至 1993-03-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=8916161&HistoricalAwards=false
关键词：
Stratigraphy Sedimentology Paleontology Provenance Uppermost

项目摘要

This research will 1)determine the provenance, depositional environment, and mechanics and direction of sediment transport for volcaniclastic sandstone bodies within the uppermost Gazelle Formation 2) determine more accurately the age of the uppermost Gazelle Formation by generating a conodont biostratigraphy 3) to better constrain the timing of amalgamation of the Yreka-Callahan terrane and the Trinity Ultramafic Complex by: a) evaluating contact relations between the Gazelle Formation and the Trinityh Ultramafic Complex and b) U-Pb dating of zircon from a pluton that cuts a thrust contact between the two terranes. This work will provide important constraints on three competing models for the accretionary history of lower Paleozoic eugeoclinal terranes in California and Nevada. In addition, the study will bear directly on any evaluation of the hypothesis that supracrustal terranes in the eastern Klamath Mountains occur within extensional allochthons. In doing so, research will fill a conspicuous gap in reconstructions of Devonian paleogeography. Existing reconstructions simply label regions in California and western Nevada as "island arc" environments. We must provide better resolution via well-constrained local geologic histories if we are to evaluate further the existing models of tectonic development outlined above.

这项研究将 1) 确定最上部瞪羚组内火山碎屑砂岩体的来源、沉积环境以及沉积物迁移的机制和方向 2) 通过生成牙形刺生物地层学更准确地确定最上部瞪羚组的年龄 3) 更好地约束通过以下方式确定怀里卡-卡拉汉地体和 Trinity 超镁铁杂岩合并的时间： a) 评估各地体之间的接触关系瞪羚地层和 Trinityh 超镁铁杂岩体以及 b) 对来自切断两个地体之间逆冲接触的岩体的锆石进行 U-Pb 定年。这项工作将为加利福尼亚州和内华达州下古生代常地斜地体的增生历史的三个竞争模型提供重要的约束。此外，这项研究将直接影响对克拉马斯山脉东部的表壳地体出现在伸展异地岩内的假设的任何评估。这样做，研究将填补泥盆纪古地理重建中的一个显着空白。现有的重建只是将加利福尼亚州和内华达州西部的地区标记为“岛弧”环境。如果我们要进一步评估上述构造发展的现有模型，我们必须通过严格约束的当地地质历史提供更好的解决方案。