甘肃宝积山盆地中侏罗世石拐茨康叶表皮构造及古环境意义  

Cuticular of Czekanowskia(Vachrameevia) shiguaiensis from the Middle Jurassic in Baojishan Basin,Gansu and its paleoenvironmental significance

作　　者：刘军[1,2] 马利涛[1] 彭琳[1,2] 陈应权[1,2] 张立[1,2] 范俊杰[3] 闫德飞[1,2] LIU Jun MA Li-tao PENG Lin CHEN Ying-quan ZHANG Li FAN Jun-Jie YAN De-fei(School of Earth Sciences, Lanzhou University, Lanzhou 730000, China Key Laboratory of Mineral Resources in Western China, Gansu Province （Lanzhou University ）, Lanzhou 730000, China Gold Geological Institute of CAPF, Langfang 065000, Hebei, China)

机构地区：[1]兰州大学地质科学与矿产资源学院,兰州730000 [2]甘肃省西部矿产资源重点实验室,兰州730000 [3]武警黄金地质研究所,河北廊坊065000

出　　处：《世界地质》2016年第4期909-919,共11页World Geology

基　　金：国家自然科学基金(41272026);兰州大学中央高校基本科研业务费专项资金(lzujbky-2013-112)联合资助

摘　　要：甘肃宝积山盆地中侏罗统窑街组发现茨康类植物化石,通过对其外部形态和表皮构造研究,认定为石拐茨康叶(Czekanowskia(Vachrameevia)shiguaiensis)。对比当前化石及其现存最近对应种(the nearest living equivalent species)—Ginkgo biloba L.的气孔比率,得到宝积山盆地在中侏罗世的古大气CO_2体积分数为1.55×10^(-3),数值接近GEOCARBⅢ碳平衡模型的拟合曲线,表明茨康叶属植物也是恢复古大气CO_2体积分数的良好材料。同时,通过角质层特征进行古环境重建,结果表明宝积山盆地在中侏罗世时期气候较为温和湿润。Czekanowskialean fossils are discovered from the Middle Jurassic Yaojie Formation in the Baojishan Basin,Gansu.They are assigned to Czekanowskia（Vachrameevia） shiguaiensis Sun et al.according to the leaf morphology and epidermal structures.Compared the stomatal ratio between the fossil and the nearest living equivalent species--Ginkgo biloba L.,the value of CO2 concentration in the Middle Jurassic Baojishan Basin was deduced as about 1.55 × 10-（-3）,which is closer to fitted curve of the GEOCARB Ⅲ carbon balance model.It shows that Czekanowskia（Vachrameevia） shiguaiensis might be a good fossil plant for reconstructing paleoatmospheric CO2 level.The results indicate that the climate of Baojishan Basin was warm and wet in the Middle Jurassic.

关 键 词：甘肃 宝积山盆地 中侏罗世 石拐茨康叶 古大气CO_2浓度 

分 类 号：P534.52[天文地球—古生物学与地层学] Q914.2[天文地球—地质学]