关键词: 主量元素, 微量元素, 稀土元素, 红土剖面, 风化层

Abstract: The red soil formed by carbonate weathering has preserved the historical evidence of karst development and evolution, and it
is also an important object of soil research in karst area. In this paper, the two typical carbonate profiles in Shilin area of Yunnan were
selected to study the migration characteristics and distribution of the major elements, trace elements, and rare earth elements in the
weathering crusts, and further explore the genesis of the weathering crust. The results show that: (1) using the migration
characteristics of Ti as the reference element, the major elements of the two sections show similar migration patterns in the process
of soil formation, and most of them are characterized by leaching. The trace elements are slightly different and the degree of
leaching is different. (2) UCC normalized spider graphs show that Ca and Sr in the weathered crust are depleted with respect to thebedrock; Fe, Ti and other elements are slightly enriched in comparison to UCC, Mg, Ca, Na, K, P, and other elements show a large
decrease. (3) The REE distribution patterns of the weathering crust and bedrock are similar, but the REE of the weathering crust is
relatively rich, the difference between light rare earth elements is large while the difference between heavy earth elements is smaller,
and the ratio of light and heavy rare earth elements in the SJC profile is larger than that of the QST profile; After normalization of rare
earth element chondrites, Eu in the SJC section shows a negative anomaly. Ce negative anomalies are observed in the upper and lower
part of the section. The QST profile shows negative Ce anomalies and negative Eu qnomalies. (4) The change in elemental content and
the correlation of Al-Ti, Al-Fe and Zr-Hf with elemental elements show that the overlying red soil is a result of weathering of the
underlying bedrock. The results of this study show that the elemental geochemical characteristics of the two profiles have good
inheritance of the bedrock and the weathering layer is the in-situ weathering product of the bedrock.

Key words: major elements, trace elements, rare earth element, red earth profile, regolith