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气候和构造环境在很大程度上控制了沉积系统中碳酸盐沉积物和硅质碎屑沉积物之间过渡的性质。为了说明这些关系的细节,本文讨论了两个选自潮湿热带环境、一个选自干旱热带环境的三个实例。尼加拉瓜东陆架区是潮湿热带环境下硅质碎屑沉积物和碳酸盐沉积物成指状交错发育的地区。本区极高的降雨量(海岸平原南部达4.5米/年)加上沉积物向近岸陆架相应的高输入量,形成了由硅质碎屑沉积物占主导的内陆架。贸易风导致的海水的密度梯度和持久的动量迫使混浊的海岸水南流,把硅质沉积物限制在一个与海岸平行的近20千米宽的带内。宽阔陆架的其它部分以碳酸盐沉积物和礁为特征。中陆架区具有由大部分为钙质绿藻仙掌藻属组成的粗粒碳酸盐沉积覆盖层。外陆架显示出伴有礁发育的崎岖地形。骨骸碳酸盐含有丰富的珊瑚和珊瑚藻粒,具有陆架向海边缘的特征。大量的硅质碎屑沉积物限于陆架近岸部分,从硅质碎屑沉积物到碳酸盐沉积物之间的过渡出现在不足20千米的距离内。第二个例子选自印尼潮湿热带环境下细粒硅质碎屑沉积物环绕的活礁体组合。温暖而多雨气候使印尼群岛的火山岩迅迷风化,丰富的沉积物输入水深仅4070米的巽他陆架。在北半球冬季时,季候风驱使的海洋过程使海水和沉积物沿着爪哇海长轴向东搬运。夏季时,搬运方向又反过来。这种双向过程体系不仅在礁和碳酸盐台地的形态上留下了痕迹,而且也造成了从邻近物源区来的硅质碎屑的广泛分布。孤立的礁以及小而成长条形环绕礁的碳酸盐台地(长0.6—10千米)高出大部分由硅质碎屑沉积物组成的海底40—50米。在这一例子中,岩相过渡极为突然。在环境条件堵截了这些台地的遣碳酸盐群落之前,碳酸盐岩隆以及伴生的骨骸沉积物与广泛而丰富的硅质碎屑沉积物共存。
The climate and tectonic setting largely control the nature of the transition between carbonate sediments and siliciclastic sediments in sedimentary systems. To illustrate the details of these relationships, this article discusses two examples from a humid tropical environment, one from a tropical tropical environment. The Nicaragua EBL is an area where the siliciclastic sediments and carbonate sediments are finger-like and staggered under humid tropical environment. The extremely high rainfall in the region (4.5 m / yr south of the coast plains) coupled with the corresponding high input of sediments into the nearshore shelf resulted in an inland shelf dominated by siliceous sediments. The density gradient and long-lasting momentum of seawater caused by trade winds forced the turbid coast to run south and trap siliceous sediments within a nearly 20 kilometer-wide band parallel to the coast. The other parts of the wide shelf are characterized by carbonate sediments and reefs. The mid-shelf area has a coarse-grained carbonate overlay consisting mostly of Calcium alginatensis. The continental shelf shows rugged terrain with reef development. Bone carbonate carbonate is rich in coral and coral algae, with the characteristics of the shelf to the sea edge. Large amounts of siliciclastic sediments are confined to the nearshore of the shelf and the transition from siliceous sediments to carbonate sediments occurs within less than 20 kilometers. The second example is from a combination of live reefs surrounded by fine-grained siliceous clastic sediments in moist tropical Indonesia. The warm and rainy weather fanned the volcanic rocks of the Indonesian archipelago. The rich sediments were fed into the Sunda shelf at a depth of only 4,700 meters. During the northern hemisphere winter, monsoon driven ocean processes move seawater and sediment eastward along the long axis of the Java Sea. In summer, the handling direction is reversed. This two-way process system not only left traces on the reef and carbonate platforms but also resulted in the widespread distribution of siliciclastic debris from adjacent source areas. Isolated reefs and small, growing bar-shaped carbonate platforms (0.6 to 0.6 km long) are 40 to 50 meters above sea level, mostly composed of siliceous sediments. In this case, the facies transition is extremely abrupt. Precipitation of carbonate rocks and associated bone deposits coexists with extensive and abundant siliceous clastic sediments before environmental conditions intercept the de-carbonated communities in these stations.