Cyclic Carbonates and Vail-Sequences on Carbonate Platforms:A Field and Modelling Study

我们将详细记录美国西部晚寒武纪和密西西比纪的经典地层剖面，并测试旋回性的证据。我们将利用Fischer（1964）首次使用的技术的新应用，研究如何将1至10米旋回打包成更大规模（1至10米持续时间）的韦尔型序列。定义相对海平面的短期变化。该技术提供了一种强大的、客观的方法，可以在1到10米的尺度上定义起伏和下沉的影响，并可以识别旋回碳酸盐岩的层序边界。我们将对现场记录的地层序列进行一维计算机模拟，并进行二维模拟以生成地层剖面，这些剖面可以与实际剖面进行比较，显示出岩石类型的米尺度、垂直和横向变化。我们的模型能够利用复杂的海平面曲线生成均衡的、模拟的地层剖面和显示米尺度岩石变化的截面，这是研究碳酸盐旋回所必需的。我们将对序列中较深的水相进行光谱分析，以确定在较深的水相中是否存在米兰科维奇气候变化的记录。计算机模拟将受到地质数据的限制。这种方法将使我们对碳酸盐岩旋回如何在碳酸盐岩台地上排列、如何包裹在维尔层序中，以及各种类型的异旋和自旋机制如何控制古生代碳酸盐岩旋回的发育有更深入的了解。研究将记录气候和海平面变化对沉积岩堆积的影响。

We will to log in detail, and test for evidence of cyclicity, classic stratigraphic sections in the Late Cambrian and Mississippian of the western U.S. We will examine how the 1 to 10 m cycles may be packaged into larger scale (1 to 10 m.y. duration) Vail-type sequences, utilizing a new application of a technique first used by Fischer (1964), to define short term changes in relative sea level. The technique provides a powerful, objective method of defining eustatic vs. subsidence effects at 1 to 10 m.y. scale, and allows recognition of sequence boundaries in cyclic carbonates. We will run 1-dimensional computer simulations of the stratigraphic sequences logged in the field, and 2-dimensional simulations to generate stratigraphic cross-sections that may be compared with actual cross-sections showing meter scale, vertical as well as lateral changes in rock types. Our models are capable of utilizing complex sea level curves to generate isostatically balanced, simulated stratigraphic sections and cross-sections showing rock changes at the meter-scale, necessary for a study of carbonate cycles. We will perform spectral analysis on deeper water facies in the sequences to determine if there is any record of Milankovitch climatic changes in the deeper water facies. The computer simulations will be constrained with geological data. This approach should provide us with a much firmer understanding of how carbonate cycles are arranged on carbonate platforms, how they are packaged in Vail-sequences, and how the various types of allocyclic and autocyclic mechanisms control their development in the Paleozoic. Research will document the effects of climatic and sea level change on the accumulation of sedimentary rocks.