黔北务正道地区早二叠世大竹园期岩相古地理及其对铝土矿的控矿意义  

Lithofacies Paleogeography of the Dazhuyuan Age,Early Permian in the Wuchuan-Zheng′an-Daozhen Area,Northern Guizhou Province and Its Implication for Bauxitisation

作　　者：雷志远[1] 翁申富[1] 陈强[1] 熊星[1] 潘忠华[1] 和秀林[1] 陈海[1] 

机构地区：[1]贵州省地质矿产勘查开发局106地质大队,贵州遵义563000

出　　处：《地质科技情报》2013年第1期8-12,共5页Geological Science and Technology Information

基　　金：贵州省地勘基金项目"贵州务正道地区铝土矿基础地质和成矿规律研究"

摘　　要：对黔北务正道地区早二叠世岩相古地理特征及其对铝土矿矿床的控矿意义进行了分析。认为位于赤道附近的炎热潮湿的古气候环境导致的红土化铁铝质古风化壳是铝土矿形成的先决条件;以页岩为主经长期化学风化形成的古剥蚀区为铝土矿的形成提供了丰富的成矿物质来源,而低凹的古地形地貌是沉积或堆积型铝土矿的最佳场所;在半封闭式的相对较为稳定的海湾相沉积环境下沉积铝土矿含矿岩系,早二叠世大竹园晚期,通过频繁的海进-海退循环,沉积区不断处于还原—氧化环境的交替变换之中,为铝土矿的形成提供了保障。This paper reports a lithofacies palaeogeographic study of the Dazhuyuan age, Early Permian in the Wuchuan-Zheng＇an-Daozhen area, northern Guizhou Province and its implication for the regional baux- itisation. It is suggested that tropic hot and humid paleoclimate and development of laterized Fe-A1 weathe- ring crust were the prerequisite for the regional bauxitisation, whereas weathering and erosion of basement shales from the long-term uplifted terrain had abundantly led to the bauxite deposits. It is also shown that the depression sites in paleogeomorphology greatly benefited deposition of the high-A1 sediments and then their bauxitisation. Lithofacies paleogeographic proofs indicate that the ore-hosted sedimentary strata were developed in a semi-enclosed and stable bay, and that due to frequently recycling of transgression-regres- sion during the Dazhuyuan age, Early Permain, the sedimentary profiles experienced multiple switches be- tween reduction and oxidation conditions, which promoted high-grade bauxitesation.

关 键 词：黔北务正道 铝土矿 岩相古地理 早二叠世 控矿意义 

分 类 号：P618.45[天文地球—矿床学]