COLLABORATIVE RESEARCH: Neogene Sediments of the San Timoteo Badlands, Southern California: Tectonic Implications Along the San Andreas and San Jacinto Faults

合作研究：南加州圣蒂莫托荒地的新近纪沉积物：沿圣安德烈亚斯断层和圣哈辛托断层的构造意义

• 批准号: 9205023
• 负责人: Michael Woodburne
• 金额: $ 9万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-07-15 至 1995-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9205023&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Neogene; Sediments; San

This proposal is to study the stratigraphy, biostratigraphy, and geochronology of the San Timoteo Badlands. It contains a sequence of nonmarine deposits about 12,000 feet thick that ranges in age from about 5 to 0.7 Ma, yields remains of fossil mammals throughout the sequence, and contains lithologies amenable to magnetostratigraphic and isotopic age analysis. The deposits, the Mt. Eden and San Timoteo formations, occur in well exposed outcrops of an anticline that plunges gently northwestward and is truncated on its southwestern edge by the currently active San Jacinto fault. The San Jacinto, the most active strand of the San Andreas fault system in southern California, underwent about 24 km of right slip during the past two million years. Paleocurrent data indicate that the sediments were transported to the San Timoteo basin from the north and northeast. Distinctive clast suites in the rocks are consistent with derivation from sources in those directions now northeast of the Badlands; some east of the present San Andreas fault (s.s). The San Timoteo beds thus are ideally situated in space and time to promote investigations of the slip history of elements of the San Andreas fault system during the past 5 million years. These beds are the only sequence that accumulated relatively continuously during this span of time in this part of southern California. A detailed analysis of age of these beds has never been attempted. The program of age analysis will include vertebrate paleontology and biostratigraphy, magnetostratigraphy and isotope chronology. If successful, the results will dramatically improve our ability to attempt a reconstruction of the sedimentary history of the San Timoteo beds, and palinspastic reconstructions of the tectonic block that contains them relative to the then adjacent terranes in this region. The data also will be valuable in addressing the timing of transfer of regional slip from the San Andreas fault strands (s.s) to the San Jacinto fault, will improve our ability to evaluate when and how the entire San Andreas system became effectively "locked" in this region; will sharpen the focus of local investigations of slip rates on the San Andreas, and on how regional shear between the Pacific and American plates is propagated through the Transverse Ranges province.

这个建议是为了研究地层学，生物地层学， 和地质年代学。 它包含一个 厚约12，000英尺的非海洋沉积序列， 年龄在5 ~ 0.7Ma之间，产生了哺乳动物化石 整个序列，并包含岩性适合 磁性地层学和同位素年龄分析。 存款， 山Eden和San Cortteo地层，出现在暴露良好的露头中 指一个背斜向西北方向倾斜， 位于其西南边缘的圣哈辛托断层附近 圣哈辛托是圣安德烈斯断层最活跃的一段 加州南部的一个系统，经历了大约24公里的右滑 在过去的两百万年里。 古水流资料表明， 这些沉积物是从 北部和东北部。 岩石中独特的碎屑岩套是 与这些方向的来源一致， 荒地的东北部;现在的圣安德烈亚斯的一些东部 故障（s.s）。 因此，圣巴斯蒂奥床是理想的位置， 空间和时间，以促进调查的滑动历史， 在过去的500万年里， 年 这些床是唯一积累的序列 在这段时间里， 南加州。 对这些岩层年龄的详细分析 企图。 年龄分析程序将包括脊椎动物 古生物学和生物地层学、磁性地层学和同位素 年表 如果成功，结果将大大改善 我们试图重建沉积历史的能力 的圣巴斯蒂奥层，和palmographic重建的 相对于当时相邻的构造块体， 在这个地区的居民。 这些数据也将是有价值的， 解决从San转移区域滑移的时间问题， 安德烈亚斯断层股（s.s）到圣哈辛托断层，将改善 我们评估整个圣安德烈亚斯系统何时以及如何 有效地“锁定”在该地区;将突出重点 当地对圣安德烈亚斯的滑动率进行了调查， 太平洋板块和美洲板块之间的区域剪切力 在横贯山脉省传播