Small Scale Depositional Sequences in a Middle Devonian Foreland Basin

中泥盆统前陆盆地的小规模沉积层序

• 批准号: 8816856
• 负责人: Carlton Brett
• 金额: $ 9.9万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-02-15 至 1992-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8816856&HistoricalAwards=false
• 关键词: Small; Scale; Depositional; Sequences; Middle

Many authors have stressed the significance of small-scale stratigraphic cycles and discontinuity bounded sequences in geochronology and in understanding depositional processes. As a result of extensive detailed studies of event stratigraphy of the Middle Devonian (Hamilton Group), we have recognized numerous small- and large-scale cyclic, bounded packages, some of which are widely traceable and appear to be allocyclic in nature. We also postulate that: 1) an upward-shallowing motif, at least in larger-scale cycles, is not pervasive, rather cycles are subsymmetrical near basin centers, but grade marginward into asymmetrical shallowing-upward sequences; 2) that the bounding surfaces of packages may record either sea level fall or rise, but 3) that they represent discontinuities of considerable magnitude; 4) depocenters of successive cyclic sequences display a regular westward migration that is consistent with current models of thrust loading in foreland basins. As a test of the generality of these patterns we will thoroughly document the sedimentology, taphonomy, paleontology and regional distribution of small-scale coarsening-upward sequences of the Hamilton Group in central New York State, and their correlatives in other areas. In particular, we will focus on a) correlation of bounded cycles across a shelf-to-basin profile; b) lateral symmetry changes within cycles; c) internal facies anatomy of small scale cyclic packages; and d) the nature and temporal scale of bounding surfaces. This research will lead to better understanding of relative sea-level fluctuations and depositional dynamics of a muddy foreland basin and could serve as a model for interpreting similar settings throughout the geologic record.

许多作者强调了小规模的重要性。 地层旋回和不连续边界层序 地质年代学和了解沉积过程。 作为 事件地层学的广泛详细研究的结果 中泥盆统（汉密尔顿群），我们已经认识到许多 小规模和大规模的循环，有界包，其中一些 是广泛可追踪的，并且似乎是异源循环的。 我们 也假设：1）向上变浅的主题，至少在 更大规模的周期，不是普遍的，而是周期 在盆地中心附近次对称，但边缘向内倾斜， 不对称的浅向上层序; 2）边界 包装的表面可能记录海平面下降或上升， 但3）它们代表了相当大的不连续性， 连续旋回层序的沉积中心显示 有规律的向西迁移， 前陆盆地逆冲加载模式 为了测试这些模式的普遍性，我们将 彻底记录了沉积学埋藏学古生物学 小规模向上粗化的区域分布 位于纽约州中部的汉密尔顿群的序列，以及 其他领域的相关人员。 特别是，我们将重点 关于a）陆架-盆地边界旋回的相关性 轮廓; B）周期内的横向对称变化; c）内部 小规模循环包的相解剖;和d）性质 和边界表面的时间尺度。 这项研究将导致 更好地了解相对海平面波动， 泥质前陆盆地的沉积动力学， 作为一个模型来解释类似的设置在整个 地质记录