(貴州理工學院資源與環(huán)境工程學院，貴陽550003)
摘 要: 通過野外地質調查、手標本觀察、巖石光面分析、偏光顯微鏡觀察、XRD分析、掃描電鏡分析等手段對黔北務川-正安-道真地區(qū)(務正道)鋁土礦中的鮞粒進行了系統(tǒng)研究。結果表明：鋁土礦含礦巖系中鮞粒按成分可分為鋁土質鮞粒、綠泥石鮞粒、硬水鋁石鮞粒、赤鐵礦鮞粒、黃鐵礦鮞粒；鋁土礦中的粗碎屑顆粒為盆地內部形成的內碎屑，泥質粗碎屑顆粒并不反映高能環(huán)境，鋁土礦中的硬水鋁石為常溫常壓條件下形成；除部分赤鐵礦鮞粒外，大部分鋁土礦中的鮞粒為低能條件下或淋濾過程中在孔隙中原位形成，綠泥石與硬水鋁石交替凝聚形成核心和同心層；持續(xù)的淋濾作用會破壞鮞狀構造，鮞狀礦石向碎屑狀或半土狀礦石轉變，使鋁土礦品質進一步提高。
關鍵字: 鮞粒；成因；鋁土礦；黔北地區(qū)
（College of Resources and Environmental Engineering, Guizhou Institute of Technology, Guiyang 550003, China）
Abstract:By means of field geological investigation, hand specimen observation, rock smooth surface analysis, polarized light microscope observation, XRD and SEM analysis, the oolites in Wuchuan-Zheng’an-Daozhen area (WZD) in northern Guizhou, China, were systematically studied.The results showthat, according to the composition, the oolites in bauxite ore-bearing rock system can be divided into aluminous oolite, chlorite oolite, diaspore oolite, hematite oolite and pyrite oolite. The coarse clastic particles in bauxite are the internal clasts formed in the basin, while the argillaceous coarse clastic particles do not reflect the high energy environment. The diaspore in bauxite was formed under normal temperature and pressure. In addition to some hematite oolites, most of the oolites in bauxite formed in situ in the pores under the condition of lowenergyconditionorleachingprocess, and chlorite and diaspore alternately agglomerated to form the core and concentric layer structure. Continuous leaching destroyed the oolitic structure, and transformed the oolitic bauxite ore to clastic or half-earthy ore, further improved the quality of bauxite.
Key words: oolite; origin; bauxite;northern Guizhou
