Age and Paleogeographic Implications of a Pre-Tertiary Flora in the Blue Mountains, Northeastern Oregon

俄勒冈州东北部蓝山地区前第三纪植物群的年龄和古地理意义

• 批准号: 8804130
• 负责人: Sidney Ash
• 金额: $ 5万
• 依托单位: Weber State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1991-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8804130&HistoricalAwards=false
• 关键词: Age; Paleogeographic; Implications; Pre; Tertiary

The principal investigator will collect and study the Jurassic flora which was recently discovered in one of the allochthonous pre-Tertiary terranes in the Blue Mountains of northeastern Oregon. A preliminary examination of several small collections of these fossils has shown that the flora consists of both well preserved leaf impressions and permineralized wood representing a variety of ferns, seed ferns, cycadophytes, ginkgos, and conifers. A detailed study of this flora will provide new data to test the hypothesis that the pre-Tertiary terranes in the Blue Mountains originated in a near-equatorial location and were subsequently displaced hundreds or even thousands of kilometers before colliding with the North American craton sometime during the Mesozoic. Also, the work will establish the age of the flora, information which should shed light on the timing of the movements of these terranes. The project will emphasize a comparison of the Blue Mountain flora to other Mesozoic floras to which it might possibly be related, especially the Jurassic and Lower Cretaceous floras that have been described from many localities around the rim of the Pacific Ocean basin. In addition, the general paleoclimatic requirements of the flora will be evaluated in order to learn something about the climatic regime in which it probably lived.

首席研究员将收集和研究最近在俄勒冈州东北部蓝山的一处异地前第三纪地体中发现的侏罗纪植物群。 对这些化石的几个小集合的初步检查表明，植物区系由保存完好的叶印和代表各种蕨类植物、种子蕨类植物、苏铁植物、银杏树和针叶树的透矿化木材组成。 对这种植物区系的详细研究将提供新的数据来检验这样的假设：蓝山的前第三纪地体起源于赤道附近的位置，随后在中生代的某个时候与北美克拉通碰撞之前移动了数百甚至数千公里。 此外，这项工作还将确定植物区系的年龄，这些信息将有助于揭示这些地体运动的时间。 该项目将强调将蓝山植物群与可能与之相关的其他中生代植物群进行比较，特别是在太平洋盆地边缘许多地方描述的侏罗纪和下白垩纪植物群。 此外，还将评估植物群的一般古气候要求，以便了解其可能生活的气候状况。