内蒙古银根-额济纳旗盆地白垩系中硅化木化石及其沉积环境  

Early Cretaceous Silicied Woods from the Yingen-Ejinaqi Basin,Inner Mongolia and Their Sedimentary Environment

作　　者：张明震[1] 戴霜[1] 陈世强[2,3] 张文防[1] 张永全[1] 赵杰[1] 张莉莉[1] 张瑞[1] 

机构地区：[1]兰州大学西部环境教育部重点实验室,西部环境与气候变化研究院,兰州730000 [2]兰州大学地质科学与矿产资源学院,兰州730000 [3]甘肃省地质矿产开发局第四地质矿产勘查院,甘肃酒泉735000

出　　处：《地质学报》2013年第8期1059-1066,共8页Acta Geologica Sinica

基　　金：国家自然科学基金(编号40972025;40721061;40571017);教育部新世纪人才计划(NCET-07);高等学校学科创新引智计划(B06026);中央高校基本科研业务费专项(编号860711)共同资助的成果

摘　　要：内蒙古银根-额济纳旗盆地是我国北方重要的中-新生代陆内含油气盆地,主要出露白垩系冲洪积-河湖相碎屑岩及火山岩夹层。本文描述了在盆地东南部下白垩统巴音戈壁组下段(1号)和苏红图组二段底部(2号)发现的上、下两处原始埋藏的硅化木化石,并探讨了早白垩世时期盆地沉积时的气候环境。两处化石均保存完好,表面结构较为完整。巴音戈壁组上部和苏红图组下部泥岩段孢粉分析结果显示地层时代为早白垩世中晚期。同时,孢粉植物群揭示该时期银根-额济纳旗盆地气候环境温暖湿润,植被茂盛。根据化石保存特征和产出位置的地层岩性,初步推测1号硅化木化石点系冲洪积物快速堆积所致,2号硅化木化石点系火山喷发物瞬间埋藏所致,其埋藏时代大致为早白垩世晚期。Yingen-Ejinaqi Basin, a Mesozoic-Cenozoic intermountain petroliferous basin in Inner Mongolia, northern China, is largely filled by the Cretaceous alluvial-fluvial-lacustrine clastic sediments interbedded with volcanic layers. Two sites of well-preserved silicied woods were discovered in the I.ower Cretaceous Bayingebi Formation and Suhongtu Formation in the southeastern Basin. In this paper, we firstly described the taphonomic characteristics and morphological structures of silicied woods and then discussed the climatic environment when they buried based on the palynologic datas. In addition, palynological samples were collected from the upper Bayingebi Formtion and lower Suhongtu Formtion. The palynological study suggests a late Early Cretaceous age, and also reflects a wet and warm climate in this area. According to the lithological characters, the first locality of the fossil woods was rapidly buried by intermittent floods, debris flows deposits. And the second ones was suddenly covered by pyroclastic deposits which possibly occurred at the late Early Cretaceous period on the basis of published dates.

关 键 词：硅化木 孢粉 银根-额济纳旗盆地 早白垩世 内蒙古 

分 类 号：P512.2[天文地球—地质学]