金佛山地质旅游考察记

<正>金佛山素以丰富多彩的动植物资源而闻名,然而在地质学家眼里,她又呈现出另一幅魅力无穷的面孔:藏身于二叠纪地层中的蜂巢珊瑚和蜓类化石,岩石界线记录的古环境变化事件……在这本记录了地质沧桑巨变的"万卷书"中,还蕴藏着更多的自然奥秘。对于金佛山,我早有耳闻,可惜一直无缘踏访。金佛山是植物研究者的天堂,有5100多种植物,种数是缙云山的3倍。作为一名地质和古生物工作者,我更关注这里与万盛石林一样的龟裂纹灰岩和山中的厚层状灰岩,推测里面一定大有文章。2013年4月20日至5月20日,适逢金佛山上杜     

Noeggerathiales as coal-forming plants in Cathaysia: conclusions from an Early Permian vegetational Pompeii in Inner Mongolia

Noeggerathiales are an extinct group of sporebearing plants of uncertain systematic position that are known from Carboniferous and Permian age Euramerican and Cathaysian floras that occurred in presentday Europe, North America, and East Asia. The order Noeggerathiales includes over 50 species of more than 20 fossil genera, but their paleoecology is not well understood yet. Previously this group had been found only in extrabasinal floras or those inhabiting clastic wetlands. Noeggerathiales have never been recorded in coal ball floras. Thus, it is up to now uncertain whether this group has contributed to the formation of coal. Recent investigations of an Early Permian peatforming flora of the Taiyuan Formation near Wuda, Inner Mongolia, which was preserved in a volcanic ash fall has provided evidence that noeggerathialean plants not only existed in the peatforming vegetation but could even be the dominant group in some areas of the coal swamp. The Noeggerathiales in this particular peatforming forest include Tingia unita, Paratingia wudensis, and a new species of Paratingia. Exceptionally well-preserved specimens indicate that these noeggerathialean plants are small trees with a canopy of compound leaves and strobili near the top of an unbranched （monocaulous） stem.     

川西YS-1井玄武岩特征及与峨眉山玄武岩对比

探讨位于传统峨眉山大火成岩省之外的YS-1井玄武岩的特征及其与邻区峨眉山玄武岩的联系,为区域地质研究和油气勘探提供参考。YS-1井玄武岩总厚度达258 m,下与中二叠统茅口组灰岩呈火山喷发不整合接触,可见灰岩大理岩化;上与上二叠统龙潭组呈假整合接触。依据岩石组合及层序特征,共划分出16个韵律,归为3个旋回。岩相以溢流-喷溢相为主;初步研究显示玄武质多孔熔岩为主要的储层岩石类型,第三旋回上部为储层发育的有利部位。地球化学特征显示其属亚碱性-碱性过渡的高钛玄武岩,具洋岛玄武岩(OIB)特征;富集大离子亲石元素,稀土配分模式呈右倾平滑型,与峨眉山玄武岩相似。轻、重稀土分异程度揭示其岩浆起源于石榴子石二辉橄榄岩区的低度熔融;强不相容元素特征显示其源区受到陆壳或岩石圈地幔轻微混染。岩相特征、构造环境判别结果为板内玄武岩,属裂隙式喷发。该套玄武岩属于峨眉山大火成岩省的一部分,即YS-1井玄武岩的发现将峨眉山玄武岩分布范围扩大到了成都一带。     

二叠纪末大灭绝后双壳类新的辐射

研究了二叠纪未生物大灭绝事件后双壳类的首次辐射,辐射的代表是贵州青岩地区中三叠世Anisian晚期的青岩生物群,共50余属100余种,归在5亚纲10目18超科32科。以往通常认为双壳类的辐射发生在晚三叠世,以阿尔卑斯地区圣·卡息安生物群为最早代表;但根据研究,大灭绝后双壳类的首次辐射时代比以往认为的圣·卡息安生物群早约1000万年。     

The first record of Helicoprion Karpinsky （Helicoprionidae） from China

A new species,Helicoprion jingmenense sp. nov.,from the Lower Permian Qixia Formation of Hubei Province,China,is described based on a nearly complete symphyseal tooth spiral preserved as part and counterpart. The specimen is a large elliptical symphyseal tooth spiral with 41/3 volutions,with cutting blade being relatively wide,and its width being greater than the height after 31/2 volution,middle portion being higher than the cutting blade,narrowed base being short. There is a distinct space not covered by enameloid in two adjacent tooth crowns in the outermost two volutions; the height of the compound root is moderate,and the ventral groove is about 1/10 of the same tooth crown. In com-parison with other known Helicoprion species of the world,the new species resembles H. ferrieri and H. bessonowi. However,it can be easily distinguished from H. ferrieri by the wider cutting blade,the shorter narrowed base and lower compound root,and also from H. bessonowi by its more narrowed compound root and less than 39 tooth crowns per volution. Helicoprion jingmenense sp. nov. is obvi-ously different from helicoprionid species previously found in China in general shape,size and his-tology. However,it is very difficult to identify their relationships because of the fragmentary nature of holotypes of the latter. Because the new specimen is the first record of Helicoprion and the most com-plete fossil dentition of helicoprionids from China,the new species is of significance for biostratigra-phy and paleobiogeography.     

岑溪二叠纪岛弧型玄武岩的首次厘定及大地构造意义——两广交界古特提斯构造带的重要证据

<正>两广交界岑溪一带的细碧角斑岩建造未有专门的研究工作,不少学者撰文时皆沿袭了广西地质志(1985)中的说法,认为是夹于下志留统含笔石复理石中的火山建造,是早志留世洋底火山作用的产物。笔者对白板至大爽基性火山岩进行了野外调研,发现该处火山岩和地层存在复杂的构造叠置关系,其中大爽村头山上志留系明显地推覆在细碧角斑岩等火山建造之上。在白板至大爽约2km的路线剖面上,黑色火山岩(指细碧岩、角斑岩、枕状玄武岩、火山角砾岩等)断断续续时有出露,围岩地层为志留系、泥盆系和石炭系,近白板一带主要为灰岩、硅质岩及泥质页岩,时代为石炭纪,大爽一带主要为志留系黑色页岩、砂质粉砂质泥岩(1:50000图过程中认为其中有些为石炭纪的深海建造),也有零星的石灰岩分布,彼此呈断层接触关系。笔者的野外工作初步认为该处存在构造混杂堆积,而认为细碧角斑岩不是志留系中的夹层。     

临清坳陷(东部)石炭二叠系煤成气勘探远景

临清坳陷（东部）煤炭资源丰富，石炭二叠系煤系烃源岩埋藏深、分布广，是煤成气勘探的有利地区．自其沉积以来经历了均衡、停止、补偿和差异演化四个阶段，形成了现今比较复杂的热演化格局．按照不同地区的埋藏历史，可以把它们划分成回返型和中隆新凹型两种，后者是煤成气生成和保存的有利地区．结合埋藏热演化史，对临清坳陷（东部）石炭二叠系煤系烃源岩主生气期进行了确定，并计算了其资源量     

塔里木盆地北缘陆相二叠系中的植物化石

新疆塔里木盆地北缘二叠纪陆相地层中的植物化石丰富，共现２８属４８种，本文对其中的８属９种作了详细的描述了讨论，当前材料不仅大大丰富了塔北二叠纪植物群的内容，对塔北二叠纪地层的划分与对比具有重要作用，而且为塔北二叠纪植物地理区系和古板块位置的研究提供了新论证。     

生物大灭绝与臭氧层变薄

2．52亿年前的二叠纪生物大灭绝导致了90％的海洋生物灭绝，陆地生物也有70％以上毁灭。陆地上原本繁盛的两生类、爬行类动物和昆虫等几乎消失得一干二净，海洋中无脊椎动物和珊瑚等生物更是损失惨重。即使在白垩纪（约1.5亿年前）末期的恐龙灭绝，其毁灭规模也只有二叠纪末期生物大灭绝的1／3。     

三塘湖盆地二叠纪构造层划分及其构造特点

目的研究二叠纪构造层的划分及其构造特点。方法依据三塘湖盆地二叠纪地层与上覆地层的区域性不整合关系在地震剖面上的反映及其不同构造层的构造变形差异性，划分出二叠纪构造层，并对其构造格局和残留构造特点进行研究。结果二叠纪沉积盖层形成后，遭受晚海西期构造运动的影响，导致中央拗陷带残余二叠纪地层中宽缓褶皱和冲断构造组合的发育；在遭受多期构造叠加改造后，残余的二叠纪构造层在盆地中表现为西南部残余厚度大，东北部残余厚度小的现今构造格局。结论二叠纪构造层具有残留盆地的特征，主要含油层分布在条湖凹陷的西南缘和马郎凹陷。