CAJ | 학술논문

贵州省施秉县云台山景区喀斯特地貌主要由寒武纪白云岩组成,其白云石含量多在90%以上,无论是基底中的白云石,还是内碎屑中的白云石均呈自形-半自形晶体。白云岩中CaO的平均含量为30．4%,MgO的平均含量为21．7%,与白云岩的理想含量相当。白云岩Sr的平均含量为72．4×10-6,Sr/Ba比值大于1,反映其为海相沉积。白云岩的稀土总量低,仅为12．54×10-6,Eu具较弱负异常,Ce基本无异常,稀土配分模式为轻稀土富集的右倾型。白云岩的形成环境总体表现为局限台地上的泻湖潮下环境,水体较浅,水流不畅,水动力弱-中等。成岩环境以弱还原-还原条件为主,干燥炎热是其古气候条件的特点。在干燥炎热的气候条件下,先期形成的碳酸钙沉积物,经强烈蒸发而形成泻湖卤水,通过向海方向的渗滤回流被交代而形成白云岩,属准同生期-早成岩阶段近地表的交代白云岩。
귀주성시병현운태산경구객사특지모주요유한무기백운암조성,기백운석함량다재90%이상,무론시기저중적백운석,환시내쇄설중적백운석균정자형-반자형정체。백운암중CaO적평균함량위30．4%,MgO적평균함량위21．7%,여백운암적이상함량상당。백운암Sr적평균함량위72．4×10-6,Sr/Ba비치대우1,반영기위해상침적。백운암적희토총량저,부위12．54×10-6,Eu구교약부이상,Ce기본무이상,희토배분모식위경희토부집적우경형。백운암적형성배경총체표현위국한태지상적사호조하배경,수체교천,수류불창,수동력약-중등。성암배경이약환원-환원조건위주,간조염열시기고기후조건적특점。재간조염열적기후조건하,선기형성적탄산개침적물,경강렬증발이형성사호서수,통과향해방향적삼려회류피교대이형성백운암,속준동생기-조성암계단근지표적교대백운암。
The karast landforms in the Yuntai Mountain area, Shibing, Guizhou are dominantly made up of the Cambrian dolostones in which the dolomite contents come up to 90%, and display euhedral-subhedral crystals. The dolostones in this area have the contents of 30. 4% for CaO, 21. 7% for MgO and 72. 4 × 10-6 for the average of Sr contents with the Sr/Ba ratios of more than 1 , and are characterized by low ΣREE ( 12 . 54 × 10-6 ) , slightly negative Eu anomaly, and right-leaning LREE-enriched distribution patterns. It is inferred that the dolostones were originated from the lagoon-subtidal environments within the restricted platforms with shallower water depths and weakly to moderate hydrodynamic environments, and xerothermic palaeoclimatic conditions. Influenced by the xerothermic climates, the pre-existing calcium carbonates were highly evaporated to give rise to the lagoon brines, and the seaward infiltration and seepage reflux of the brines finally resulted in the formation of the dolomites. It follows that the dolostones in the study area should be assigned to the near-surface replacement dolostones generated during the penecontemporaneous-early diagenetic stages.