The Middle Cretaceous carbonate ramp of the northern Sinai: sequence stratigraphy and facies distribution
The Middle Cretaceous carbonate ramp of the northern Sinai: sequence stratigraphy and facies distribution
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西奈半岛北部中白垩世碳酸盐斜坡：层序地层和相分布
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
J. Kuss
中科院分区：
文献类型：
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作者：
M. Bachmann;J. Kuss
西奈半岛北方中白垩世碳酸盐岩斜坡发育于被动大陆边缘之上的两个阶段。北部以三角洲为主的下斜坡（上阿普特安-下阿尔比安）演化为以碳酸盐为主的上斜坡（中阿尔比安-塞诺曼阶），覆盖了西奈半岛的中部和东南部。两个斜坡设置之间的过渡发生在一个时期的第二阶海平面上升和气候条件的重大变化。沉积模式叠加了更高频率的相对海平面变化。在相模式、沉积几何学和微相类型分布的基础上，重建了三级相对海平面变化对斜坡沉积的影响。由于区域构造运动的重要性是次要的，层序地层学解释允许一个不断变化的斜坡设置和他们的特点的精细规模的估计。半定量微相分析和层序地层学的结合使用允许在不同的体系域，包括各自的微相分布的控制沉积的因素的研究。这些因素表明，三级海平面波动的结果，不仅在简单的相带向上和向下的斜坡，但也在变化的环境因素，如水循环，碳酸盐生产和硅的输入。
Abstract The Middle Cretaceous carbonate ramp of the northern Sinai developed in two stages on a passive continental margin overlying basal rift suites. The lower delta-dominated ramp (Upper Aptian-Lower Albian) in the north evolved into the upper carbonate-dominated ramp (Middle Albian-Cenomanian) which covered the central and southeastern parts of the Sinai. The transition between the two ramp settings took place during a period of a second-order sea-level rise and a major change in climatic conditions. The sedimentary patterns are superimposed upon by higher-frequency relative sea-level changes. The influence of the third-order relative sea-level changes on the ramp deposition was reconstructed on the basis of facies patterns, sedimentary geometries, and the distribution of microfacies types. As regional tectonic movements were of subordinate importance, a sequence stratigraphic interpretation allows a fine-scale estimation of the changing ramp settings and their characteristics. The combined use of semiquantitative microfacies analysis and sequence stratigraphy allows study of the factors controlling deposition during the different systems tracts, including the respective microfacies distributions. These factors indicate that third-order sea-level fluctuations result not only in simple shifts of facies belts up and down the ramp but also in changing environmental factors such as water circulation, carbonate production and siliciclastic input.