| 其他摘要 | Yunnan-Guizhou Plateau widespread with large areas of carbonate rock weathering crust. This evolution of lateritic weathering crust and the local ecological environment, climate livelihood is closely linked. In this paper, the research means stratigraphy, petrology and geochemistry to explore the region lateritic weathering crust provenance issues, and discuss migration characteristics and distribution of the elements in the chemical weathering of carbonate and compare its rock weathering profile and argillaceous rocks weathering profile of difference. We selected a well-developed profile of primary dolomite and mudstone profile at Xinpu town, Zunyi, Guizhou as study object. Zr is treat as immobile element, we get following conclusion: 1) Lateritic weathering crust in the region is weathering crust formed in situ, source weathering crust of carbonate rocks of the underlying bedrock. The transference of trace elements (Zr as not activate element) in the cross-sectional distribution with good regularity, no large mutation, which is consistent with the native characteristics of the cross section. In addition, the distribution of minerals also showed an increase in less exotic minerals. Meanwhile, the distribution of major elements in the cross section of the types of minerals along with the change, and there is no obvious mutation. These can be used as the cross-section is based on the in situ formation. Meanwhile, the elements of Nb-Ta, Zr-Hf and Y-Yb in the two profiles are very strong correlation, it can be used as identification of the cross-sectional area no post-weathering of rocks stacked basis.2) Most trace elements show enrichment during leaching process especially maximization at rock-soil interface. Nb、V and Hf are immobile elements. 2) The dolomite and shale weathering profile weathering profile cross-section is formed in situ leaching. Migration coefficient distribution of trace elements in the two sections have good regularity. Cross-section in the Dolomites, the majority of trace elements in the weathering process exhibited enriched features, especially in the rock - to maximize soil interface, which shows the weathering and leaching process. The migration coefficient of trace elements in shale weathering profile migration coefficient of less than a majority of elements in weathering profiles dolomite, dolomite and shale which shows the different elements subjected to migration activity under the same conditions, chemical weathering. Nb, V, and Hf in both the cross-sectional elements are not activated. 3) Light rare earth elements in dolomite rock weathering profiles - soil interface enrichment factor is greater than the heavy rare earth elements, which indicates that compared to LREE HREE leaching process easier activation. In contrast, the shale section in the light - heavy REE migration coefficient difference is not large, which indicates the different lithologies different role in the control of the same kinds of mineral elements is not the same. In addition, dolomite iron shell of the relevant trace elements has enriched effect. In summary, the results of this study to investigate the Karst region lateritic weathering crust material characterization of the sources of law and weathered mudstone has important implications for. 4) With the dolomite mineral profiles change between the rocks and soil with changes in the law, the bedrock of the minerals are mainly dolomite, quartz and feldspar. Rock mineral powder mainly dolomite and quartz. But the rock - soil minerals in the soil increased significantly at the interface, including quartz, montmorillonite, illite, kaolinite, feldspar, dolomite and iron minerals. Residual soil also contains more minerals and more, some samples containing amphibole, gypsum and gibbsite. Mudstone mineral species no major changes, mainly because some clay minerals. |
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