老挝万象地区白垩系

作者对老挝万象地区进行了1∶10万区域地质调查。该地区白垩系为一套红色陆源碎屑沉积,形成于河流-湖泊环境,由新到老可划分为班塔拉组、班纳德组及普帕纳帕陶山组。地层中上部的双壳类属Trigonioides(Trigonioides)sinensis Gu et Ma-Plicatounio(Plicatounio)naktongensis Kobayashi et Suzuki动物群,下部的双壳类属Kore-anaia-Eonippononaia-Plicatounio-Peregrinoconcha动物群,介形类属Monosulcocypris-Cypridea组合,轮藻为早白垩世的标准化石。这3个组的岩石地层、生物地层及年代地层特征可与我国滇西地区的景星组、南新组及虎头寺组相对比。

The Cretaceous strata in the Vientiane region in Laos

The 1:100 000 regional geological survey has been implemented by the authors in the Vientiane region in Laos. The Cretaceous strata in this region consist of a succession of red terrigenous clastic deposits in the fluvial-lacustrine environments, and may be grouped into the Bantala, Bannade and Pupanapataoshan Formations, where there occur the bivalve faunas Trigonioides (Trigonioides) sinensis Gu et Ma-Plicatounio (Plicatounio) naktongensis Kobayashi et Suzuki in the middle and upper parts, and the bivalve faunas Koreanaia-Eonippononaia-Plicatounio-Peregrinoconcha, the ostracod assemblage Monosulcocypris-Cyridea and charophytes as the Early Cretaceous index fossil in the lower part. The lithostratigraphy, biostratigraphy and chronostratigraphy of the above-mentioned formations may be compared with those of the Jingxing, Nanxin and Hutousi Formations in western Yunnan, China.