重庆綦江中侏罗世木化石群的发现及其科学意义

THE DISCOVERY OF MIDDLE JURASSIC PETRIFIED WOOD FROM QIJIANG IN CHONGQING AND ITS SCIENTIFIC SIGNIFANCES

报道在重庆首次发现的中侏罗世木化石群。化石产地为綦江区古南镇文龙村马桑岩,地层层位为中侏罗统上沙溪庙组。木化石表面碳化,内部硅化、褐铁矿化。化石经磨片后显微镜观察,可确定为松柏类植物木材。该木化石群不仅是四川盆地地层新层位发现的木化石,且增加了我国南方侏罗纪木化石分布范围。该化石群反映了中侏罗世该地区的干燥气候,对研究当时的古气候与古地理以及沉积学具有重要价值。

The middle Jurassic petrified woods are first reported in Chongqing.The buried site is Masangyan quarry of Wenlong Village,Gunan Town,Qijiang District of Chongqing and the sediment containing woods is Shangshaximiao Formation from middle Jurassic.The surface of woods underwent coalification and the inside experienced the silicifiatiion and limonitization.The anatomy of wood shows it is a conifer.The petrified woods not only became stratigraphically new discovered fossil woods in Sichuan Basin,but expanded the distribution of Jurassic petrified woods in South China.These woods showed that the climate was relatively dry in this area during middle Jurassic and are valuable in studying the contemporaneous paleogeography,paleoenvironment and sedimentology.