(貴州理工學(xué)院 資源與環(huán)境工程學(xué)院，貴陽(yáng) 550003)
摘 要: 黔北務(wù)川-正安-道真地區(qū)(簡(jiǎn)稱務(wù)正道)鋁土礦的形成與海平面變化關(guān)系密切，綜合運(yùn)用野外地質(zhì)調(diào)查、手標(biāo)本觀察、偏光顯微鏡觀察、區(qū)域地層對(duì)比等手段對(duì)黔北務(wù)正道地區(qū)鋁土礦礦石的自然類型與海平面變化之間的關(guān)系進(jìn)行了研究。結(jié)果表明：半土狀礦石層可作為長(zhǎng)時(shí)間海退的標(biāo)志；務(wù)正道地區(qū)至少經(jīng)歷了4次海退過(guò)程，4次大規(guī)模海退是務(wù)正道地區(qū)能形成優(yōu)質(zhì)鋁土礦的重要原因；所有沉積型鋁土礦礦石自然類型都可指示含礦巖系的沉積過(guò)程，沉積型鋁土礦本身可作為一種多期次暴露標(biāo)志層。
關(guān)鍵字: 半土狀鋁土礦；海平面變化；黔北地區(qū)
（College of Resources and Environmental Engineering, Guizhou Institute of Technology, Guiyang 550003, China）
Abstract:The sea level changes is an important factor which controls the forming process of the bauxite in northern Guizhou. So, a research was carried out on the relationship between sea-level changes and the natural types of bauxite ores in Wuchuan-Zhengan-Daozhen area (short for WZD) in Northern Guizhou by comprehensive use of field geological investigation, hand specimen observation, microscopic observation and regional stratigraphic correlation based on the previous studies. The results show that the natural types of ores can be regard as marker bed of sea level changes, and earthy ore bed can be seen as a sign of longstanding regression. WZD area has experienced at least 4 regressions, and the 4 large-scale regressions were an important cause for the formation of high-quality bauxite in WZD area. Land and sea transition bauxite has the similar structure features, and the natural types of ores in all the sedimentary bauxite can be used to distinguish the sedimentation cycle of the ore-bearing rock formations. The sedimentary bauxite in themselves can be regarded as a multi-stage exposure marker bed.
Key words: earthy bauxite; sea level change; northern Guizhou
