Sequential extraction of core samples collected from Pulicat Lake, east coast of India, showed that on average, 59% of labile Cr and 28% of labile Al remain adsorbed onto Fe–Mn oxides. Similarly, 61% of labile Al and 36% of labile Cr are associated with organic matter. Cross‐correlation analysis revealed that in the Fe–Mn oxides phase, Cr primarily exists with Mn‐oxides, while Al remains mainly adsorbed onto Fe‐oxides. Factor analysis revealed four factors that could explain 82% of the variance in the data. Changes in water column ionic composition, salinity, dissolution of Fe–Mn oxides during microbial oxidation of organic matter, changes occurring to the organic matter and calcium carbonate during early diagenesis are the key factors influencing the Al and Cr concentrations in the labile fractions. The results of this study are useful to interpret palaeoenvironmental conditions.

中文翻译：

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铬和铝的古环境应用：有关分区和早期成岩运动的关注

从印度东海岸Pulicat湖收集的岩心样品的顺序提取表明，平均而言，59％的不稳定Cr和28％的不稳定Al仍然吸附在Fe-Mn氧化物上。同样，61％的不稳定Al和36％的Cr与有机物有关。互相关分析表明，在Fe-Mn氧化物相中，Cr主要与Mn-氧化物一起存在，而Al仍主要吸附在Fe-氧化物上。因素分析揭示了四个因素，这些因素可以解释数据中82％的方差。水柱离子组成的变化，盐度，有机物微生物氧化过程中Fe-Mn氧化物的溶解，早期成岩过程中有机物和碳酸钙的变化是影响不稳定组分中Al和Cr浓度的关键因素。