湖泊纹层状沉积物的同生期变化研究述评

湖泊纹层状沉积物是在湖水分层的条件下缓慢沉积的。这些沉积物在沉积以后可能会发生一些同生期的改造作用，如季节性湖流的微弱冲刷、湖水中溶解氧对有机质的氧化、硫酸盐还原作用对有机质的氧化和硫化物的形成、有机质分解形成的偏酸性底层湖水对碳酸盐的溶解和磷的迁移造成的藻类勃发等，使纹层在成分、结构和构造方面发生一些变化。在对纹层进行古气候、古环境恢复的时候，这些同生期的变化不能被忽视。对这些变化的研究有助于对古气候、古湖水沉积环境的正确认识。

Syngenetic Changes in Lacustrine Lamellar Sediments

Lacustrine lamellar sediments slowly deposit in column stratified lake water. The lamellar sediment would develop some syngenetic changes, such as the weak scouring of seasonal lake water stream, the oxi dization of dissolved oxygen and sulphate to organics in underlayer lake water, the formation of sulphide, the dissolution of carbonate in acid underlayer water caused by decomposition of organic matter, the algal bloom be cause of migration of P. These changes are shown in composition, texture and structure of lamellar sediments, and should not be ignored in the research of palaeoclimate or palaepsedimentary environment through lamellar sediment. The study of the changes is helpful for better understanding the palaeoclimate and palaeosedimentary environment.