The characteristics of aluminum-bearing rock series and the regularity of lithium enrichment in Yangjiaping in Northern Guizhou

Lithium is widely used in various industries today, especially with the rapid development of new energy and related industries in recent years, which has sparked fierce competition among countries for lithium resources. The Yangjiaping Area in Northern Guizhou is a newly discovered lithium anomaly area in recent years. This paper explores the stratification characteristics of aluminum -bearing rock series and the regularity of lithium enrichment, through prospecting engineering exposure, statistical analysis of 617 chemical samples, combined with XRD testing and other methods. The research shows the aluminum-bearing rock series can be divided into six layers, with Layers ①, ③, and ④ being the most commonly developed. Lithium is primarily enriched in the middle-upper dense bauxite rock of the Dazhuyuan Formation（P₁d）, The Layers ⑤ and ⑥ at the top are underdeveloped. Since the upper Layers ⑤ and ⑥ of the aluminum-bearing rock series are undeveloped, this indicates that the top section is not the main host of lithium, while also suggesting that the bauxite deposits in the area are not of significant scale. The lithium content varies across rock types, ranked as follows: dense bauxite rock（ore）＞clastic/oolitic dense bauxite rock（ore）＞bauxite rock＞clastic bauxite ore＞aluminous claystone. The uneven development of sub-layers and varying lithium enrichment levels suggest that the aluminum-bearing rock series underwent multiple stages of weathering and leaching during sedimentation and diagenesis. The enrichment of lithium is related to the main chemical components, with a critical point of Al₂O₃ content at 45%. When ω（Al₂O₃）＜45%, Al₂O₃ is positively correlated with Li₂O, when ω（Al₂O₃）＞45%, Al₂O₃ is negatively correlated with Li₂O. When the aluminum-silicon ratio is less than 2, the aluminum-silicon ratio is positively correlated with Li₂O, when the aluminum-silicon ratio exceeds 2, the aluminum-silicon ratio is negatively correlated with Li₂O. When ω（Li₂O）＞0.40%, Fe₂O₃ is generally less than 5%. In aluminum-rich rock series, positive correlation with chlorite, negative correlation with illite, suggesting lithium-bearing chlorite as the primary host mineral.