Sedimentologic and Chronostratigraphic Analysis of Cenozoic Strata, Southern Margin of Colorado Plateau: Tectonic and Paleogeographic Implications

科罗拉多高原南缘新生代地层的沉积学和年代地层分析：构造和古地理意义

• 批准号: 8817402
• 负责人: J. Dale Nations
• 金额: $ 8万
• 依托单位: Northern Arizona University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-06-01 至 1992-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8817402&HistoricalAwards=false
• 关键词: Sedimentologic; Chronostratigraphic; Analysis; Cenozoic; Strata

Cenozoic nonmarine sedimentary and volcanic rocks of the southern Colorado Plateau and adjacent Verde Basin are divided into five tectonostratigraphic packages that document stages in the evolution of the transition zone between the Colorado Plateau and the Basin and Range provinces in central Arizona. These two units are differentiated on the basis of, 1) geomorphic position, 2) clast composition and provenance variations, 3) tectonic setting and structural history, and 4) radiometric ages of intercalcated volcanics. The areal extent, lithology, provenance, depositional environments and age of these stratigraphic units are poorly constrained, and differences of opinion exist as to their interpretation. One school of thought is that the Colorado Plateau escarpment was formed by erosion during the Oligocene, and the other is that it was formed by extensional faulting beginning during the Miocene, less than 10 million years ago. Until these contradictory interpretations of the geologic history of the Plateau margin are resolved, the tectonic and geomorphic history of the Colorado Plateau and Basin and Range provinces remains speculative. This study will establish the age relationships, and environmental and tectonic history of the Cenozoic rocks in the southern Colorado Plateau-Mogollon Rim area. These interpretations will be based on petrologic and facies analyses of five tectonostratigraphic packages and more precise definition of their ages based on paleontology, K-Ar and fission track dating.

新生代陆相沉积岩和火山岩 南部科罗拉多高原和邻近的维德盆地被分割 分成五个构造地层包， 科罗拉多高原和 以及亚利桑那州中部的盆地和山脉省。 这两 单元的区分是基于：1）地貌位置， 2)碎屑成分和物源变化，3）构造 背景和构造历史; 4） 层间火山岩 分布范围、岩性、物源、沉积 这些地层单位的环境和时代较差 有分歧，有分歧，有分歧，有分歧。 解释。 一种观点认为科罗拉多号 高原陡坡是在渐新世的侵蚀作用下形成的， 二是由伸展断裂作用形成 始于中新世不到一千万年前 直到这些对地质历史的矛盾解释 高原边缘的构造和地貌 科罗拉多高原和盆地山脉省历史 仍然是推测。 本研究将建立年龄关系， 新生代岩石的环境和构造历史 南部科罗拉多高原-莫戈隆边缘地区。 这些 解释将基于岩石学和相分析 五个构造地层包和更精确的定义 根据古生物学、K-Ar和裂变径迹， 约会