美国迈阿密地区更新世鲕粒滩发育特征及控制因素

通过对迈阿密鲕粒滩与现代鲕粒滩的类比,将高分辨率的卫星激光雷达绘图与露头信息结合起来,可视化了迈阿密鲕粒滩的整体形态以及其中的沉积特征,潮汐通道的分布直接影响鲕粒滩的形态,迈阿密鲕粒滩的形成与潮汐作用有密不可分的联系;在迈阿密鲕粒滩中的沉积相主要发育交错层理的鲕粒相和生物潜穴型泥质鲕粒灰岩相,其中可见羽状交错层理以及大量的生物遗迹化石,证实迈阿密鲕粒滩的形成受到潮汐作用的影响;迈阿密鲕粒滩经历了胶结作用和溶蚀作用等多种成岩作用,其中胶结作用会破坏其孔渗性,而在溶蚀作用的影响下会增加其孔渗性。在对迈阿密鲕粒滩中的典型露头进行了实地考察后,进一步确认了迈阿密鲕粒滩是受到潮汐作用而形成的现代鲕粒滩。

Pleistocene Oolite Development Characteristics and Controlling Factors in Miami, USA

Through the analogy between Miami oolite and modern oolite. The high-resolution LiDAR "mapping" and outcrop are combined to visualize the overall morphology of Miami oolite and depositional characteristics. It is considered that the formation of this unit is related to tidal action. The sedimentary facies of Miami oolite mainly developed cross-bedded ooid grainstone and burrow-mottled ooid-peloid grainstone, in which bi-directional cross-bedding and a large number of bio-relic fossils was visible. It is confirmed that the formation of the unit was affected by tidal action. Miami oolite undergoes cementation and dissolution. The pore permeability was destroyed under the influence of cementation, and the pore permeability was increased under the influence of dissolution. After investigating the outcrop of the Miami oolite, it is further confirmed that the oolite is a modern oolite formed by tidal action.