【摘要】 滇西北固东一瑞滇盆地第四纪沉积物类型多,层序全,其中砂锡资源丰富。在此进行第四纪地层研究既有理论意义,又有实际意义。本文对该盆地的第四纪地层进行了详细划分,并对环境演化问题进行了探讨。更多还原

【Abstract】 Gudong - Ruidian basin is located at the north - western edge of the Yunnan Plateau, near the boundary between China and Burma. It is a small intermontane fault - subsidence basin, formed in the beginning of Quaternary. The sediments in the basin are very different ranging from those of alluvium , lacustrine deposit, pluvial sediments to volcanic edifices. This area is also very famous for its volcanic landscape and thermal activities.This paper is focused on the classification of strata. According to the principles and methods of stratigraphy, chronology, geomorphology, a lot of analyses have been made. The Quaternary strata in the basin can be subdivided into Xiashanzhai Formation, Gejiashan Formation, Longzhaogou Formation , Gudong Formation and so on.Based on the study of the strata, the Quaternary history and environment evolution in this area are reconstructed as the following:1. Basin ?forming stage ; 2. Stream - valley stage; 3. Volcanic dammed lake stage; 4. Stream - lake stage; 5. Tengliang movement stage; 6. Volcanic dammed lake stage; 7. Stream - developing stage.The placer of tin deposits in the Gudong - Ruidian basin are very abundant, they exist in the sediments of every epoch throughout Quaternary.更多还原