四川盆地自流井组东岳庙段植物化石及下-中侏罗统的界线

对采自四川盆地云阳一带自流井组东岳庙段14属18种植物化石进行了研究，其中描述1个新种Stachypteris? anomala Meng(sp．nov.)和1个首见于区内的种Klukia exilis(Phillips)。东岳庙段植物组合的重要分子是从下伏珍珠冲段延续而来的，这表明此组合基本承袭了珍珠冲段的组合面貌。依据Dictyophyllum nilssoni，D．nathorsti，Otozamites hsiangchiensis等尚未见于中侏罗世和自流井组明显分为两大沉积旋回，指出东岳庙段的时代属早侏罗世托尔期(Toarcian)和四川盆地下-中侏罗统的界线以划在自流井组东岳庙段与马鞍山段之间为宜。

FOSSIL PLANTS FROM DONGYUEMIAO MEMBER OF THE ZILIUJING FORMATION AND LOWER-MIDDLE JURASSIC BOUNDARY IN SICHUAN BASIN, CHINA

In recent years, more fossil plants, including 14 genera and 18 species, have been found from the Dongyuemiao Member of the Ziliujing Formation in Sichuan Basin. Of them, a new species and a species discovered for the first time in this basin, i.e. Stachypteris? anomala Meng (sp. nov.) and Klukia exilis (Phillips), are described here. All the important elements of the plant assemblage from the Dongyuemiao Member were extended up from the Zhenzhuchong Member, which shows that this assemblage basically inherited the assemblage aspect of the Zhenzhuchong Member. On the ground that Dictyophyllum nathorsti, D. nilssoni and Otozamites hsiangchiensis have not been recorded in Middle Jurassic and the Ziliujing Formation is subdivided into two sedimentary cycles, it is suggested that the Dongyuemaio Member is of Toarcian age and the Lower Middle Jurassic boundary is placed between the Dongyuemiao Member and the Ma'anshan Member of the Ziliujing Formation.