藏北羌塘盆地上侏罗统中硅化木的发现及意义

Discovery and significance of fossil woods in the Upper Jurassic Qiangtang basin,northern Tibet

首次在藏北羌塘地区晚侏罗世晚期地层中发现的硅化木,对硅化木的基本特征进行了描述,初步鉴定其属南洋杉型木,并在同一层位中采集了大量孢粉。结合区域地质以及产出硅化木地层的沉积学特征等简要分析认为,羌塘地区晚侏罗世具干热气候,属全球四大植物分区中的欧洲-中国亚区。显然,这一发现有助于我们认识青藏高原晚侏罗世的构造演化及气候环境。

Recently fossil woods have been for the first time discovered in late Late Jurassic strata in the Qiangtang basin,northern Tibet.Their basic features are described.Primary identification suggests that the fossil woods are Araucarioxylon,and large quantities of sporopollen have been collected in the same horizon.On the basis of studies of the fossil woods and sporo-pollen,combined with the regional geol-ogy and primary analyses of the sedimentological features of the strata where the fossil woods occur ,the authors think that the Late Jurassic climate was dry and hot in the Qiangtang area,and that this area belongs to the Europe-China subrealm of four flora realms in the world.It is evident that this discovery may help us understand the Late Jurassic tectonic evolution and the climate and environment in the Qinghai-Tibet Plateau.