Depositional Cycles, Diagenesis and Composite Sea Level Changes in Platform Carbonates of the Alpine Triassic

浅水碳酸盐沉积通常是在104-105年的频率范围内，在米级尺度上分期沉积的。这项拟议的研究将增加我们对这种地层旋回性的起源和意义的理解，利用阿尔卑斯山三叠纪碳酸盐岩的绝佳暴露作为天然野外实验室。早期的工作表明，具有米兰科维奇周期的复合海平面变化在这些三叠纪碳酸盐岩的旋回沉积中发挥了基本作用。这项研究将通过仔细的野外和实验室研究阿尔卑斯山三叠系碳酸盐岩的沉积学、成岩作用和地层学，为了扩大这一早期工作，以弥合高频米级旋回(104-105年)和更大的三级旋回(106年)之间的差距，三级沉积旋回是地震和层序地层学的基本单位。如果浅水碳酸盐(它们是可靠的海平面测量仪)对104年、105年和106年的复合海平面周期、下沉和沉积的相互作用的响应可以预测(或至少可以理解)，那么我们将有一个强大的工具用于地层对比，露头或钻孔岩心的年代地层学和层序地层学比目前的地震地层学方法所能检测到的尺度更精细。这些信息在勘探碳酸盐岩浅水矿床中常见的碳酸盐岩油气藏和热液矿床方面具有明显的价值。

Shallow water carbonate deposits typically were deposited episodically at the meter-scale in the frequency range of 104-105 years. The proposed research will increase our understanding of the origin and significance of this stratigraphic cyclicity, using the superb exposures of Triassic carbonates in the Alps as natural field laboratories. Earlier work has demonstrated that composite eustatic sea level changes with Milankovitch periodicities played a fundamental role in the cyclical deposition of these Triassic carbonates. The research will attempt, by careful field and laboratory study of the sedimentology, diagenesis and stratigraphy of a spectrum of Alpine Triassic carbonates, to extend this early work to bridge the gap between high frequency meter-scale cyclicity (104-105 year) and the much larger 3rd order scale (106 year) depositional cycles that are the fundamental units of both seismic and sequence stratigraphy. If the response of shallow water carbonates (which are reliable sea level gauges) to the interaction of composite 104, 105 and 106 year sea level cycles, subsidence, and sedimentation can be predicted (or at least understood), then we will have a powerful tool for use in stratigraphic correlation, chronostratigraphy and sequence stratigraphy at an outcrop or borehole core scale finer than that detectable by current seismic stratigraphic methods. Such information would have obvious value in the exploration for hydrocarbon reservoirs and hydrothermal ore deposits that are so commonly hosted in shallow water carbonate deposits.