甘肃靖远、景泰早石炭世维宪期植物群

祁连山和河西走廊区石炭纪地层发育，动植物化石丰富，是研究我国海陆交互相石炭系的重要地区。臭牛沟组系袁复礼(1925)所建，标准地点在甘肃武威西南35km的臭牛沟，据其中的腕足类和珊瑚化石的研究，确定其时代为早石炭世维宪期(Visean)。研究材料来自甘肃景泰和靖远的早石炭世臭牛沟组，这里的臭牛沟组厚约120m左右，由泥质页岩夹煤线、粉砂岩及薄层泥灰岩、灰岩组成，为潮间潟湖相至滨海沼泽相及泥炭沼泽相沉积。含丰富的植物化石，主要分子有Sublepidodendron sp. , Lepidodendronciyaoense sp. nov. , Lepjingyuanense sp.nov. , Lepidodendron volkmannianum , Lep. gansuense sp. nov. , Lep. shanyangense, Lep. cf. aolungpulukense,Lep. sp. 1, Lep. sp. 2, Cathaysiodendron jingyuanense, C. cf. incertum, Stigmaria ficoides, Lepidostrobophyllum cf. lanceolatum, L. rotundi folium sp. nov., Lepidostrobus sp. 1, L. sp. 2, Bothrodendron ruchengense, Archaeocalamites scrobiculatus , Hamatophyton uerticillatum , Cardiopteridium spetsbergense , C. podozamioides,Triphyllopteris collombiana , Triphyllopteris sp. ( cf. T. lescuriana Lesquereux), Rhacopteris sp. , Adiantites gothanii, Sphenopteris sp. 1, Sphenopteris sp. 2, Rhodeopteridium hsianghsiangense, R. cf. hsianghsiangense,R. cf. chinghaiense, Rhodeopteridium sp. (cf. R. lipoldi) , Paripteris gigantea , P. cardiopteroides, Linopteris sp. , Codonospermum sp. , Trigonocarpus spp. , Cardiocarpus cordai, Cordaites sp. (cf. C. schenkii Halle) 。其下伏地层前黑山组中有菊石Kazakhstania sp．，为下石炭统底部Gattendor fia带分子，其余还有孢子化石、腕足类和植物，表明为杜内期沉积；而上覆地层靖远组底部有牙形石Gnathodus bilineatus bollandensis，G．bilineatus bilineatus，Paragnathodus commutatus及P．nodosus，是我国下石炭统顶部德坞阶的一个牙形石带化石；筵化石：Mediocris breviscula，M．pilatus，M．cf．minima，Eostaffella galinae，E.cf．mediocris是我国和卅l组常见分子，也产于贵州罗甸的德坞阶(相当于早期纳缪尔阶)。臭牛沟组产有大量孢子，可分3个孢子带，分别可以和西欧维宪期孢子带(PV，TC，NM)对比。在当前的植物群中Cathaysiodendron及Bothrodendron ruchengense，Le pidodendron shanyangense的发现，对于研究早石炭世植物地理区的划分，华南和西北同期植物群的对比及东方型鳞木类的演化均具有重大意义。

A VISEAN FLORA (CHOUNIUKOU FORMATION) FROM JINGYUAN AND JINGTAI IN GANSU, NORTHWESTERN CHINA

In China, the terrestrial-marine inter-deposited Carboniferous are best developed in Qilian Mountain and Hexi Corridor, where both fauna and plant fossils are well preserved and can be compared to that of Europe and North America. Here a Visean flora is reported. The plant bearing Chouniukou Formation is 120m thick, consists of muddy shale, coal seams, clay, silty sandstone and marl, representing deposits of inter-tide lagoon, coastal swamp and peat swamp. The fossil plants include: Sublepidodendron sp., Lepidodendron gansuense sp. nov., Lepidodendron volkmannianum, Lep. jingyuanense sp. nov., Lep. ciyaoense sp. nov., Lep. shanyangense, Lep. cf. shanyangense, Lep. cf. aolungpulukense, Lep. sp.1, Lep. sp.2, Cathaysiodendron jingyuanense, C. cf. incertum, Lepidostrobophyllum rotundifolium sp. nov., Bothrodendron ruchengense, Archaeocalamites scrobiculatus, Hamatophyton verticillatum, Cardiopteridium spetsbergense, C. podozamioides, Triphyllopteris collombiana ,Triphyllopteris sp. Rhacopteris sp., Adiantites gothanii, Rhodeopteridium hsianghsiangense, R.cf. hsianghsiangense, R. cf. chinghaiense, Paripteris gigantea, P. cardiopteroides, Linopteris sp. This flora presents a phase of the vegetation right prior to the Namurian global glaciation from the tropical island. Features of the flora, such as the botanical significance, phytogeography, and the age determination and a comparison with other known Visean floras are detailed.