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通过揭示南海北部陆坡沉积物柱状样中铁、磷和碳酸钙等的赋存特征,结合现代表层海水中磷与水温、溶解氧的关系,讨论了海洋沉积物中铁-磷积累的环境生物地球化学过程.结果表明,沉积磷与碳酸钙的含量随深度的变化呈相反趋势,而沉积铁与碳酸钙的含量变化基本一致,这与冰期时表层海水温度降低而二氧化碳含量增高,使部分陆源磷溶入海水刺激了海洋初级生产力,从而导致生源碳酸钙在沉积物中积累的生物地球化学过程有关,也与海水中来自大气和海洋植物光合作用的氧,促使铁的氧化而加速沉淀到沉积物中有关.沉积物柱状样中可溶性铁和磷结合态(Fe-P)的含量变化,能够敏感地反映来自气候和环境变化的影响,表明了沉积物中铁和磷结合态的积累特征与赋存状况.对古气候和古环境变化具有指示意义.
By revealing the occurrence characteristics of iron, phosphorus and calcium carbonate in the sediment columnar samples from the northern South China Sea, and combining the relationship between phosphorus and water temperature and dissolved oxygen in modern surface seawater, the environmental biogeochemical processes of iron-phosphorus accumulation in marine sediments were discussed The results show that the content of sediment phosphorus and calcium carbonate changes with the depth of the opposite trend, while the sediment iron and calcium carbonate content changes are consistent with the ice age surface sea water temperature decreases while the carbon dioxide content increased, so that part of the terrestrial phosphorus dissolved Seawater stimulation of the marine primary productivity, leading to biogeochemical processes in which biogenic calcium carbonate accumulates in sediments, also relates to the oxygen in photosynthesis of seawater from the atmosphere and marine plants, accelerates the oxidation of iron and accelerates the precipitation into sediments The change of soluble iron and phosphorus-bound (Fe-P) content in sediment column samples can sensitively reflect the impact from climate and environmental changes, indicating the accumulation characteristics and occurrence of iron and phosphorus bound species in sediments. Paleoclimate and paleoenvironmental changes are indicative.