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）确定最上层的火山碎屑砂岩体的出处，沉积环境以及沉积物传输的机制和方向。凝视阵线形成2）更准确地确定最上面的凝视物构造的年龄，通过产生牙齿生物地层图3），以更好地限制肌肌层的时间，以更好地限制y Yreah yreka的时间和整个y rah yreka-c的时间。 a）评估瞪羚形成与三位一体超镁铁质配合物与b）锆石的U-pb日期之间的接触关系，从岩石上切断了两个地下室之间的推力接触。这项工作将对加利福尼亚和内华达州下古生代埃诺克派的增生历史的三个竞争模型提供重要限制。此外，这项研究将直接依靠对东部克拉马斯山脉上塔层的假设进行的任何评估。这样一来，研究将填补泥盆纪古地理重建的显着空白。现有的重建仅将加利福尼亚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面概述的现有构造发展模型，则必须通过良好的当地地质历史提供更好的分辨率。