COLLABORATIVE RESEARCH: RUI: Evaluation of Controls on Carbonate Platform Evolution and Architecture Through Comparative Platform Analysis: Nanpanjiang Basin, South China

9804835 Lehrmann了解控制碳酸盐岩台地寿命、结构和层序变异性的机制，对于碳酸盐岩台地作为古环境记录者的科学研究和油气勘探与开发具有根本重要性。 然而，碳酸盐岩平台内部相结构和层序地层对比的解释通常基于一个假设：海平面的波动是重要的控制机制。我们建议堪萨斯大学和威斯康星-奥什科什大学之间的合作项目，以评估区域和局部变量的作用，包括海平面变化，沉降，构造活动，硅碎屑流入，过量营养通量，和碳酸盐岩生产率。 这些控制的评价将通过对分布在中国南部南盘江盆地650 km 2区域内的各种规模、结构和环境的同时代三叠纪台地的比较分析来完成。 我们选择南盘江盆地是因为我们知道没有其他地区可以进行如此多样的台地规模和形态的露头研究，包括向陆的附属台地和孤立台地。我们将通过绘制露头来确定层序地层结构，这些露头暴露了通过台地的连续二维断面。 同步间隔的比较将有助于区分区域和本地控制。 我们将使用详细的生物地层学和磁反转地层学，以确保同步事件的控制机制的分离和解释进行评估。 利用这些地层和年龄数据，我们将构建沉降历史，以隔离局部变化，以便我们能够检查平台之间或平台内沿着走向的地层同步差异的可能原因。 例如，对于具有类似沉降和海平面变化历史的同时代间隔，我们将使用相分析来评估诸如硅质碎屑或过量营养物流入对碳酸盐台地生长中断或终止的影响，并评估盆地填充硅质碎屑对沉积几何形状的影响。 最终产品将是一系列沉积模型，说明碳酸盐岩台地的实际结构变异性和对控制变异性的机制的定量理解。

9804835LehrmannUnderstanding the mechanisms that control longevity, architecture, and sequence variability of carbonate platforms is of fundamental importance in scientific studies of carbonate platforms as recorders of ancient environments and in hydrocarbon exploration and exploitation. However, interpretations of internal facies architecture and sequence-stratigraphic correlation's of carbonate platforms are commonly based on an assumption: fluctuations in sea level are the essential controlling mechanism.We propose a collaborative project between Universities of Kansas and Wisconsin-Oshkosh to evaluate the roles of both regional and local variables including sea-level changes, subsidence, tectonic activity, siliciclastics influx, excess nutrient flux, and carbonate production rates on platform architecture. Evaluation of these controls will be accomplished through a comparative analysis of coeval Triassic platforms of various scales, architectures and settings distributed over an area of 650 km2 within the Nanpanjiang Basin of south China. We have chosen the Nanpanjiang Basin because we know of no other area that allows outcrop study of as great a diversity of platform scales and morphologies, including both landward attached platforms and isolated platforms.We will determine sequence-stratigraphic architecture from mapping outcrops that expose continuous two-dimensional transects through the platforms. Comparison of synchronous intervals will aid in separating regional and local controls. We will use detailed biostratigraphy and magnetic-reversal stratigraphy to ensure that synchronous events are evaluated in the separation and interpretation of controlling mechanisms. With this stratigraphic and age data we will construct subsidence histories to isolate local variations so we can examine possible causes for synchronous differences in the stratigraphy between platforms or along strike within platforms. For example, for coeval intervals with similar subsidence and eustatic histories we will use facies analysis to evaluate the impact of variables such as influx of siliciclastics or excess nutrients on interruptions or termination of carbonate platform growth and to evaluate the impact of basin-filling siliciclastics on progradation geometries. The end product will be a series of depositional models that illustrate actual architectural variability in carbonate platforms and a quantitative understanding of the mechanisms that control variability.