| 老挝万象地区基础地质调研的主要进展 |
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| 引用本文：严城民,朱延浙,吴军,冯明刚.2006.老挝万象地区基础地质调研的主要进展[J].地球学报,27(1):81-84. |
| DOI：10.3975/cagsb.2006.01.12 |
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| 基金项目:国家发展计划委员会“老挝万象平原钾镁盐矿勘查”项目(计外资[1999]2298号) |
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| 中文摘要:经区域地质调查、专题研究及钻探工程,老挝万象地区基础地质调研取得的主要进展是:①该区地层自下而上可划分为会辛南组(P2HX)、南拉组(P2NL)、南康尚组(P2NK)、南立组(J1NL)、南舍组(J1-2NS)、班辛黑组(J2BH)、普帕纳帕陶山组(K1PP)、班纳德组(K1BN)、班塔拉组(K1BT),塔贡组(E1TG)及班塔博组(E1-2BT),其岩石地层特征可与中国滇西兰坪-思茅地区的同时代地层相对比;②在上述11个组级岩石地层单位中均获古生物资料,分属14个生物地层单位,其生物地层特征可与中国滇西兰坪-思茅地区的同时代地层相对比;③万象地区的构造变形可划分为成盐前(晚白垩世)、成盐期(古新世)、成盐后(始新世)3个时期,一级构造为塔贡叠加复式向斜、班普夸快叠加复式背斜;④含盐地层塔贡组(E1TG),为一套乳白、淡红色膏盐层及棕红、紫红色陆源细碎屑岩,膏盐层与陆源细碎屑岩构成3个明显的沉积旋回,据此可划分为3个岩性段、6个岩性层,具工业意义的钾镁盐矿均产于塔贡组下段膏盐层(E1TG1-1)中;⑤塔贡组(E1TG)可划分为滨湖、浅湖、半深湖相,在成盐过程中沉积环境发生过较明显的迁移改组,膏盐层形成于气候持续干旱、盆地基底持续下降、卤水持续补给的沉积环境。 |
| 中文关键词:老挝 万象地区 基础地质 主要进展 |
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| The Main Advances in the Fundamental Geological Investigation of Vientiane Area, Laos |
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| Abstract:The fundamental geological investigation in Vientiane area of Laos has made outstanding progress on the basis of regional geological reconnaissance, specific researches and drilling. The main achievements are as follows: ① The strata in this region can be divided upward into such formations as Houay Xiangna (P_2hx), Nam La (P_2nl), Nam Khangxang (P_2nk), Nam Lik (J_1nl), Nam Set (J_ 1-2 ns), Ban Hinheup(J_2bh), Phu Phanaphathao (K_1pp), Ban Nate (K_1bn), Ban Thalat (K_1bt), Thangon (E_1tg) and Ban Thabok (E_ 1-2 bt). Their lithostratigraphy can be compared with that of contemporaneous strata in Lanpin-Simao area, western Yunnan of China. ② From the above eleven groups of lithostratigraphic units, paleobiologic materials were obtained, which belong to fourteen biostratic units respectively. Their biostratigraphy can be compared with that of contemporaneous strata in Lanpin-Simao area, western Yunnan of China. ③ The structural features in Vientiane area can be divided into three epochs, namely before salification (Late Cretaceous), during salification (Paleocene) and after salification (Eocene). The first-class structures are Thabok superimposed synclinorium and Banphoukhaoknoay superimposed anticlinorium. ④ The saline strata, i.e., Thangon Formation (E_1tg), comprise a suite of creamy white, rose colored gypsum and halite bed and brownish red, amaranth terrigenous fine clasolite. The gypsum and halite bed and terrigenous fine clasolite constitute three distinct depositional cycles, hereby three members and six beds can be distinguished. Potassium and magnesium mines of economic value are produced in the gypsum and halite bed under Thangon Formation (E_1tg). ⑤ Thangon (E_1tg) can be divided into shore lake, medium and semi-deep lake facies. During salification the precipitation environment experienced obvious transfer and reorganization. The gypsum and halite bed was formed in a precipitation environment characterized by prolonged drought, continual subsidence of basin basement and sustained brine supply. |
| keywords:Laos Vientiane area fundamental geology main advances |
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