The Distribution of Extension with Depth in the Newark Basin: Constraints from Fission-Track Ages

纽瓦克盆地伸展随深度的分布：裂变径迹年龄的限制

• 批准号: 8721103
• 负责人: Garry Karner
• 金额: $ 5.64万
• 依托单位: Columbia University Lamont Doherty Earth Observatory
• 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: 1988-08-01 至 1990-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8721103&HistoricalAwards=false
• 关键词: Distribution; Extension; Depth; Newark; Basin

Rifting of continental lithosphere during extensional tectonics can be accomplished in a variety of ways including uniform lithospheric thinning and detachment tectonics in which extension is not uniform with depth. Each model predicts different subsidence histories subsequent to extension and these should be reflected in the sediments in filling the rift basins. Where rapid subsidence phase is followed by a slower negative exponential phase associated with contraction during cooling of the rifted lithosphere, whereas the thermal phase is reduced or absent if surface extension and rifting is detached from under- lying unextended lithosphere. The Newark Basin of Triassic- Jurassic age in the central Appalachians now consists of sediments interpreted to represent only the initial rapid subsidence phase. It is unclear if thermal phase sediments were never deposited (implying detachment tectonics) or deposited but removed by erosion (implying uniform lithosphere extension). This project will collect and interpret detrital apatite fission-track ages from a transect across the basin in an attempt to determine the maximum amount of sediment that could have been removed by erosion before Cretaceous overlap sediments were deposited. Results will bear on rifting style of the initial breakup and formation of the present Atlantic ocean, and will provide a well- documented example of continental-scale extension that can be used in comparisons to other rift basins.

伸展过程中大陆岩石圈的裂陷作用 构造学可以通过多种方式完成， 均匀的岩石圈减薄和拆离构造， 延伸与深度不一致。 每个模型预测 不同的沉降历史之后的延伸和这些 应反映在沉积物中填充裂谷盆地。 在快速沉降阶段之后是缓慢的负沉降阶段 指数期与冷却期间的收缩有关 裂谷岩石圈，而热阶段是减少或 如果表面延伸和裂谷与下方分离，则不存在。 未伸展的岩石圈 三叠纪的纽瓦克盆地- 阿巴拉契亚山脉中部的侏罗纪时期 沉积物被解释为仅代表最初的快速 沉降阶段 目前尚不清楚热相沉积物是否 从未沉积（意味着拆离构造）或沉积，但 通过侵蚀而被移除（意味着岩石圈均匀伸展）。 这 该项目将收集和解释碎屑磷灰石裂变轨迹 年龄从一个横断面横跨盆地，试图确定 最大的沉积物量， 白垩纪超覆沉积物沉积之前的侵蚀。 其结果将直接影响初始裂解的裂陷方式， 现在的大西洋形成，并将提供一个很好的- 有记录的大陆规模扩展的例子， 与其他裂谷盆地相比。