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通过地球化学研究表明 ,珠江口及北部湾盆地泥岩中稀土元素分布配分形式显示轻稀土元素富集而重稀土元素较平稳 ,铕出现明显亏损的特点 ,与澳大利亚后太古代页岩 (PAAS)的分布特点相似 ,但样品的稀土元素(REE)高于PAAS .在Th -Hf-Co三角图解中 ,所有样品也均位于上地壳平均值的上方 ,远离地壳平均值和洋壳 ,说明珠江口、北部湾盆地沉积物母岩以来自上地壳偏酸性的岩石类型为主 .地球化学判别分析结果表明珠江口盆地与北部湾盆地在源区地质背景上有较大差异 .珠江口盆地沉积物源主要以变质岩、花岗质岩系等为主 ;北部湾盆地物源区中则含相当数量的碳酸盐岩、碎屑岩 .在珠江口盆地内部珠一凹陷和珠三凹陷之间相互有 30 %左右的样品重合 ,说明两者在沉积物源上有一定比例的共同源区 .
Geochemical studies show that the REE distribution patterns in the mudstones of the Pearl River estuary and Beibu Gulf Basin show the characteristics of light rare earth elements (REEs) enrichment and heavy heavy rare earth elements (LREEs) relatively stable with obvious depletion of europium. Compared with the paleosol of late Paleozoic shale The distribution characteristics are similar but REE is higher than that of PAAS. In the Th-Hf-Co triangle diagram, all samples are also located above the average upper crust, far away from the crustal average and the oceanic crust, indicating that the Pearl River Mouth and the northern part The sedimentary parent rocks in the Bay Basin are dominated by the overly acidic rock types of the upper crust, and the geochemical discriminant analysis results show that the Pearl River Mouth Basin and the Beibu Gulf Basin have great differences in the geological background of the source area. Metamorphic rocks, granitic rocks, etc. The source rocks in the Beibu Gulf Basin contain a considerable amount of carbonate rocks and clastic rocks, and there are 30 between the Zhu 1 depression and the Zhu 3 depression in the Pearl River Mouth Basin The coincidences of the samples around% indicate that there is a certain proportion of common source regions in the sediment source.