海洋地质作用是指海洋是贮集于地球表面低洼地区的巨大水体,现约占地球面积的71%。海盆不仅容纳陆地上各种地质营力带来的物质,海洋本身的运动、生活其中的生物活动,以及海水的物理化学条件的发展和演化,在塑造岩石圈上起着极为重要的作用。地质历史中绝大多数沉积岩和沉积矿产都是海洋地质作用的产物,海洋是巨大的地质营力,其地质作用可分为海蚀作用、搬运作用和沉积作用。海水的运动方式主要是波浪、潮汐、洋流和浊流。这4种海水运动是海洋地质作用的重要的机械动力,由于海水深度和海底地形的影响,它们在海洋中构成了不同的水动力带海水较浅的滨海带和大陆架是波浪和潮汐为主的水动力带,在波浪影响不到的大陆坡和深海盆地,是洋流和浊流的水动力带,四种机械动能对海岸和海底产生海蚀等作用,使海底产生大量海洋沉积物。
海底沉积物 海洋沉积物可分为机械的、化学的和生物的3种类型,其中化学沉积物主要是来自大陆的铁、锰、铝、硅的氧化物和氢氧化物的胶体,与海水电解质相遇时,絮凝成鲕状或豆状的沉积物。海洋是陆地上最大的沉积盆地,蕴藏有丰富的矿产资源,海洋中几乎含有所有的化学元素,其中铀是获得原子能的主要元素含量达亿吨,是陆地含量的900倍。因此对海洋地质作用的研究是极其重要的,无论对地壳形成的了解及现实资源的利用都有深刻的意义。
Marine geology refers to the fact that the ocean is a huge body ofwater stored in low-lying areas of the earth's surface, which nowaccounts for about 71% of the earth's area. The sea basin not onlycontains the materials brought by various geological forces on land, butalso plays an extremely important role in shaping the lithosphere by themovement of the ocean itself, the biological activities living in it, and thedevelopment and evolution of the physical and chemical conditions ofseawater. The vast majority of sedimentary rocks and sedimentaryminerals in geological history are the products of marine geologicalaction, and the ocean is a huge geological force, and its geological actioncan be divided into sea erosion, transport and sedimentation. The waythe sea water moves is mainly waves, tides, ocean currents and turbidcurrents. These 4 kinds of seawater movement is an importantmechanical power of marine geology, due to the influence of seawaterdepth and seabed topography, they constitute different hydrodynamiczones in the ocean, the coastal zone and continental shelf with shallowsea water are hydrodynamic zones dominated by waves and tides, in thecontinental slope and deep sea basin that are not affected by waves, isthe hydrodynamic belt of ocean currents and turbidity currents, and thefour mechanical kinetic energy on the coast and the seabed produce seaerosion and other effects, so that the seabed produces a large number ofmarine sediments.
Seafloor sediments Marine sediments can be divided into threetypes: mechanical, chemical and biological, of which chemical sedimentsare mainly colloids of iron, manganese, aluminum, silicon oxides andhydroxides from the mainland, and when they meet seawaterelectrolytes, they flocculate into flocculation or bean-like sediments.The ocean is the largest sedimentary basin on land, rich in mineralresources, the ocean contains almost all chemical elements, of whichuranium is the main element to obtain atomic energy, the content ofhundreds of millions of tons, 900 times the content of land. Therefore,the study of marine geology is extremely important, and it is of profoundsignificance to understand the formation of the earth's crust and theutilization of actual resources.