地球圈层之间相互作用对白垩纪大洋缺氧与富氧过程的制约

发布时间：2018-05-29 05:51

本文选题：白垩纪缺氧 + 与富氧事件地球圈层相互作用　；参考：《中国地质》2017年04期

【摘要】：白垩纪诸多地质事件中,以黑色页岩为特征的大洋缺氧事件和以红层为特征的大洋富氧环境尤其引人关注。本文探讨了白垩纪大洋从缺氧到富氧转化的过程与机制,认为上述沉积事件是地球圈层之间相互作用的结果。白垩纪岩石圈剧烈的岩浆活动,是缺氧、富氧事件发生的源动力,水圈、大气圈、生物圈的共同作用是沉积事件发生的结果。具体过程为:白垩纪大规模的火山喷发,改变了海陆面积的对比,并引起地球内部大量热能释放和大气中CO_2气体浓度的升高,最终导致大气温度的升高。海水温度的升高和CO_2浓度的增加导致海洋环境中溶解O_2的降低,缺氧事件随之而产生。同时,海底岩浆喷发在海底产生大量的富含铁元素的基性和超基性岩石,通过海底风化和热液活动,铁元素从岩石圈进入水圈。海水中的铁元素是海洋浮游植物宝贵的营养盐类,其含量的增加可激发浮游植物的大规模繁盛,而这一生命过程可以吸收海水中大量的CO_2,并且产生等量的O_2。随着海水中O_2浓度的不断升高,以富含Fe3+的红色沉积物为特征的海洋富氧环境出现。藏南和深海钻探、大洋钻探典型剖面的数据证实大洋缺氧和富氧发生的韵律性,即缺氧事件之后往往伴随富氧环境的出现。研究认为,白垩纪大洋缺氧和富氧事件是同一原因导致的不同结果,地球圈层相互作用是其根本制约因素。由岩浆活动引起的缺氧事件和同样由其造成的富氧环境,其机制存在明显的差异,前者以物理、化学过程为主,后者除此之外还演绎了更为复杂的生物-海洋地球化学过程。
[Abstract]:In many geological events of the Cretaceous, the oceanic anoxia events characterized by black shale and the oceanic oxygen rich environment characterized by the red layer are especially concerned. This paper discusses the process and mechanism of the Cretaceous Ocean from oxygen to oxygen enrichment, and considers that the above sedimentary events are the result of the interaction between the earth's circle and the Cretaceous lithosphere. The strong magmatic activity is the source of the anoxic and oxygen rich events, the interaction of the hydrosphere, the atmosphere and the biosphere is the result of the occurrence of the sedimentary events. The specific process is that the massive volcanic eruption in the Cretaceous period changed the contrast of the area of the sea and land, and caused the release of large heat energy inside the earth and the increase of the concentration of CO_2 gas in the atmosphere. The increase of atmospheric temperature. The increase of the temperature of the sea water and the increase of the concentration of CO_2 lead to the decrease of the dissolved O_2 in the marine environment, and the occurrence of the anoxic events. At the same time, the magma eruption produces a large number of iron rich basic and ultrabasic rocks on the sea floor, and through the weathering and hydrothermal activity of the sea bottom, the iron elements enter the water circle from the lithosphere. The iron element in the water is a valuable nutrient of marine phytoplankton, which increases the mass of phytoplankton. This life process can absorb a large amount of CO_2 in the sea water, and produce an equal amount of O_2. with the increasing concentration of O_2 in the sea water, a marine oxygen rich ring characterized by the rich red deposits of Fe3+. The data of Zangnan and deep sea drilling, the typical section of the ocean drilling section confirm the rhythm of the oceanic anoxia and oxygen enrichment, that is, the oxygen rich environment often occurs following the anoxic event. The mechanism of anoxia caused by magmatic activity and the oxygen enriched environment, which is also caused by it, has obvious differences. The former is dominated by physical and chemical processes. In addition to this, the latter also deduces a more complex biological marine geochemical process.
【作者单位】：华北理工大学矿业工程学院;华北理工大学地层古生物研究中心;
【基金】：国家重点基础研究发展计划“973”项目(2012CB822000) 国家自然科学基金(41172015;41302008) 河北省自然科学基金(D2015209075;D2017209236) 河北省教育厅自然科学基金重点项目(ZD2016077) 华北理工大学省自然科学基金培育项目(SP201501)联合资助~~
【分类号】：P534.53

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