论文部分内容阅读
珠江口每年大约受12个台风袭击,是我国受台风影响最严重的地区之一。近年来对香港的部分海滩观测发现,一次强台风引起的巨浪可卷走1m厚的海滩砂。有理由相信,在珠江口全新世沉积序列中台风暴潮起着十分重要的作用。然而,至今尚未有人对其作过研究。选择有孔虫作为风暴环境的指示物,是因为其至少具备以下几个特点:(1)在沉积物中含量丰富;(2)容易区分和鉴别;(3)对环境条件,如盐度、水深等反应敏感;(4)大小和形态与一般沉积颗粒相似,壳径多处于砂和粉砂级,死亡后的壳体易被搬运和分选。研究河口相有孔虫群的性质可以指示水动力搬运作用的强度。风暴期间,强烈的风牵引流和巨浪致使大量的有孔虫壳游离海底而被搬运。因而,风暴层中的有孔虫组合性质必然与正常沉积层中的不同。
The Pearl River Mouth is hit by about 12 typhoons each year and is one of the most affected by typhoon in our country. In recent years, some beach observation of Hong Kong found that a huge typhoon caused huge waves to roll away 1m of beach sand. There is reason to believe that the typhoon outbreak in the Pearl River Estuary sedimentary sequence plays a very important role. However, no one has studied it yet. The selection of foraminifera as an indicator of a storm environment is due to its at least the following characteristics: (1) abundance in sediments; (2) ease of distinction and identification; (3) assessment of environmental conditions such as salinity, Water depth and other sensitive; (4) The size and shape of the general deposition of particles similar to shell diameter and more in the sand and silt level, after the death of the shell easily transported and sorting. Studying the properties of foraminifera in estuarine fauna can indicate the intensity of hydrodynamic transport. During the storm, intense wind traction and waves caused a large number of foraminifera shells to be transported off the seafloor. Thus, the combination of foraminifera in the stratosphere inevitably differs from that in normal sediments.