Subaqueous Sedimentary Processes Around the Mangrove Habitats in Khlong Thom and Satun Areas, South Thailand
Subaqueous Sedimentary Processes Around the Mangrove Habitats in Khlong Thom and Satun Areas, South Thailand
复制标题
泰国南部空同和沙敦地区红树林栖息地周围的水下沉积过程
作者：
S. Tsukawaki;I. Asano;T. Kamiya
在红树林栖息地广泛分布的泰国南部的空统和沙敦地区进行了水下沉积学研究，目的是阐明栖息地周围的水下沉积过程。两者的水域在沉积学上都被定义为潮流控制的河口环境。从空统地区获得了五十六个水下沉积物，从沙敦地区获得了53个水下沉积物，并进行了沉积学分析，以了解它们的结构和成分特征，以及它们的空间分布。在这两个地区进行水深和地表水化学性质的测量，以掌握水下地形和盐水！淡水混合工艺。从马六甲海峡海域到两海域的最深处，盐度都有明显的下降趋势，而表层和底层沃茨的盐度变化趋势不明显。空统地区的底表面大多覆盖着桑迪沉积物，而沙敦地区则主要是泥质沉积物。它们之间的差异主要是由于它们所处的地质环境的不同造成的。两区底部沉积物中以石英为主的桑迪陆源沉积物主要来源于两区主要出露于内部的固结地层，但底栖有孔虫和海相介形类等微生物遗迹则起源于马六甲海峡地区。此外，仅来自红树林栖息地及其周围的村庄和窑的木炭在内部的沉积物中占主导地位。由于这些沉积物全部或部分可溯源于底层沉积物中，并指示了一定的和相对的物源区，因此，主要根据它们的粒度和相对量的空间分布推断了两个地区潮流对水下沉积物的搬运途径。
Subaqueous sedimentological studies were carried out in the Khlong Thom and Satun areas, South Thailand where mangrove habitats are widely distributed, for the purpose to illustrate present subaqueous sedimentary processes around the habitats. Water areas in both are sedimen-tologically defined as tidal current dominated estuarine environments. Fifty-six subaqueous sediments from the Khlong Thom area and 53 from the Satun area were obtained and sedimentologically analysed to comprehend their textural and compositional features, and their spatial distributions. Water depth and surface water chemical properties of measurements were conduced in both areas to grasp subaqueous topographies and saline!fresh water mixing processes, respectively. A clear decrease of salinity is recognized from the Straits of Malacca area to the innermost parts in both areas, and no marked trend of it is detected between surface and bottom waters. Sandy sediments mostly cover the bottom surface of the Khlong Thom area, while muddy sediments dominate in the Satun area. The difference between them are resulted mainly from the difference of their geological settings. Sandy terrigeneous sediments consisting mainly of quartz in the bottom sediments from both areas are derived mainly from the consolidated strata cropping mainly out in the inner parts in both areas, but such micro-organic remains as benthic foraminifers and marine ostracodes are originated in the area of the Straits of Malacca. Further, charcoals derived only from villages and kilns in and around the mangrove habitats are dominant in the sediments from the inner parts. Because of these sediments are traceable wholly or partly in the bottom sediments and they indicate certain and relative source areas, course ways of subaqueous sediment transportation by tidal currents in both areas are inferred on the basis mainly of their spatial distribution of grain-sizes and relative amounts.