湖泊自生碳酸盐氧同位素环境记录研究:(二)问题

Oxygen Isotopic Records from Lacustrine Authigenic Carbonates as Environmental Change Indicators:Ⅱ. Critique

对前人提出的湖泊自生碳酸盐氧同位素组成(δ18OC)多种环境解释模型作了评述,指出了各种模型存在的局限性。提出在利用δ18OC变化进行气候和环境变化研究时,需注意气温对湖泊δ18OC的影响机制,湖水不同深度层的水温差异对化学沉积和介壳碳酸盐δ18O的影响,δ18OC和湖泊水位、降水δ18O、湖水盐度的关系,碎屑和自生碳酸盐矿物的分离,湖泊不同碳酸盐矿物间δ18O差值的确定,单矿物同位素组成的测试,不同前处理方法对δ18OC测定的影响,以及碳酸盐沉积时的不平衡效应等问题。

Environmental explanation models （EEMs） of oxygen isotopic records from lacustrine authigenic carbonates （ δ18Oc） proposed by the previous researchers, are reviewed. The paper points out the limi-tations of every EEM. Influencing mechanism of atmospheric temperature on δ18Oc, the effect of lake wa-ter temperature difference on inorganic and ostracode carbonates δ18Oc, the correlation of 81S0c with lake water level, δ18Ocof precipitation and salinity of lake water, the separation of primary and secondary car-bonate minerals, evaluation of δ18Oc difference between different carbonate is minerals, δ18O testing of signal mineral, the effect of sample preparation on δ18Oc, and the non-equilibrium effect as precipitating should be paid much attention to for the climatic or environmental interpretation of δ18Oc records