新疆阿图什温古尔地区二叠纪牙形石动物群

新疆阿图什的温古尔－巴音库鲁提一带二叠系由于化石稀少而且保存不好，地层确切时代仍存在疑问，该区温古尔剖面二叠纪重要牙形石化石Neostreptognathodus pequopensis Behnken,Streptognathodus nashuiensis Zhong et Zhang等的发现为这套地层确切时代的确定提供了重要依据。通过牙形石生物相分析，推断温古尔地区中二叠世早期可能为盆地相较深水沉积环境。     

辽宁东部中寒武世徐庄期三叶虫动物群

详细研究了辽宁东部中寒武世徐庄期的三叶虫动物群,包括45个种,分属于23个属和2个亚属.在此基础上,将中寒武统徐庄阶划分了7个生物带,其中新建生物带1个,新划分出生物带2个,并与有关地区进行了对比.     

华南和喜马拉雅古,中生代之交牙形石生物相和生物分区

在前人工作的基础上，对华南和喜马拉雅地区二叠世－早三叠世不同生态类型的牙形石进行了详细研究研究，依水体深浅不同，从浅到深识别出５种牙形石生物相即Ｈｉｎｄｅｏｄｕｓ生物相，Ｐｃａｃｈｙｃｌａ，ｄｉｎａ－ｐａｒａｃｈｉｒｏｇｎａｔｈｕｓ生物相，Ｈｉｎｄｅｏｄｕｓ－Ｇｏｎｄｏｌｅｌｌａ生物相Ｇｏｎｄｏｌｅｌｌａ－Ｎｅｏｓｐａｔｈｏｄｕｓ生物相和Ｘａｎｉｏｇｎａｔｈｎｓ生物相。通过这些牙形石生物相在时间和     

广西菜子岩剖面中上泥盆统界线附近沉积相与海平面变化*——兼论华南吉维期中期的海退及时间

广西菜子岩剖面处于台地边缘地带,含有底栖生物及浮游生物化石。综合岩相、生物相等资料,按牙形石带时限讨论了该地区吉维期—弗拉斯期早期主要的海平面变化历史。吉维期早期(相当于东岗岭组)经历了持续的海侵,大致下varcus带末期可能出现短暂的海退;“谷闭组”下部岩性复杂,海平面波动强烈,其中较大规模的包括了发生于上varcus带的海退(即吉维期中期海退)及下hermanni-cristatus带初期的海侵。吉维期晚期地层含有丰富的床板珊瑚以及其他礁体生物碎屑,产层孔虫、海百合等,意味着这个时期研究区可能处于礁前的上斜坡部位。“谷闭组”上部（牙形石falsiovalis带至transitans带下部）的岩性为中—薄层与厚层的灰岩互层,以正常的底栖生物为主,反映了由原来的礁前到滩前的变化,但水体深度在中—晚泥盆世界线前后可能总体相似。融县组(底部)以浅灰、灰白色的中—薄层至厚层—块状灰岩为特征,其沉积始于牙形石transitans带中部,证据表明此时海水可能变深。菜子岩剖面的白云岩位于上varcus带的下部,主要为细—中晶结构,见有灰岩残余以及正常海相生物碎屑。横向上与其他剖面对比表明,广西地区上varcus带可能出现了区域性的海退事件。     

湘鄂西部地区晚奥陶世三叶虫相和古地理演化

对湘鄂西地区 8个晚奥陶世剖面的 3个时段 (Caradoc中期 ,晚期及 Ashgill早期 )地层作了详细采集 ,获得了丰富的三叶虫材料 ,根据动物群的组成、分异度和各组成分子的相对丰度 ,识别出外陆棚—棚外深水区的 9种三叶虫相 ,它们在时空分布上具有逐渐过渡更替的特征。根据水中浮游类型三叶虫 (圆尾虫类 )的分异度、相对丰度以及与它们共生的底栖三叶虫生态特征 ,对各种三叶虫相所指示的水体深度作了推测。三叶虫相研究表明 ,区内Caradoc中期处于海侵高峰 ,古地理样式显示了以拉张为主的区域构造背景 ;Caradoc晚期开始发生持续海退 ,同时扬子陆块南缘受到构造挤压 ,广大外陆棚区地形变得起伏不平。晚奥陶世古地理变迁证明华夏和扬子陆块的会聚事件始于 Caradoc晚期     

上扬子区西北缘米仓山地区卡拉道克中期的三叶虫相

通过对上扬子区西北缘米仓山地区 9个剖面的详细采集 ,在宝塔灰岩 (组 )的 Xenocyclopyge jaskovitchi- Sagavia chuanxiensis三叶虫间隔带 (Caradoc中期 )获得了十分丰富的三叶虫。依据动物群的组成、属的分异度和各个属的相对丰度 ,识别出 4个与深度相关的三叶虫相 :Ovalocephalus- Dislobosaspis相和 Panderia相 ,仅含少量的cyclopygid较浅层浮游的 Microparia(Microparia) cf.speciosa,代表了浅外陆棚的环境 ;Amphytrion- Ovalocephalus相和 Cyclopyge- Cyamella相则出现了较多的在较深水域浮游的 cyclopygid分子 ,属的分异度大大增高 ,代表了深外陆棚的环境     

湘鄂西奥陶纪Tremadocian期三叶虫相

分析了湘鄂西地区 5个剖面的奥陶纪 Tremadocian期三叶虫动物群 ,识别出 6个三叶虫相 ,即台地的 Asa-phellus- Dactylocephalus相、Dikelokephalinid相、Tungtzuella- Asaphopsis相、Psilocephalina 相 ,陆棚上斜坡的Metayuepingia- shumardiid相 ,陆棚下斜坡的 Olenid相 ;恢复了该地区 C.angulatus期、P.deltifer早—中期和 P.deltifer末期— Serratognatus期三个时段的古地理面貌 ,揭示了区内发生于 G.quadraplicatus期、P.deltifer末期和 Serratognatus中—后期的三次海退事件和发生于 P.deltifer早—中期和 Serratognatus初期的两次海侵事件     

Glaciomarine deposition around the Irish Sea basin: some problems and solutions

Reconstructing the depositional processes and setting (marine or terrestrial depositional environment) of late Devensian age glacigenic sediments around the Irish Sea basin (ISB) is critical for developing an all‐embracing and consistent glacial model that can account for all observed field evidence. Identifying episodes of marine and terrestrial glacial deposition from field data is considered the first step in achieving this goal. Criteria for distinguishing marine and terrestrial glacial environments in the ISB include the geomorphology, sedimentology and faunal content (biofacies) of the associated deposits. Exposures of glacigenic sediments around the ISB are very diverse in terms of their morphosedimentary characteristics and associated biofacies, and thus inferred depositional processes and setting. Possible reasons for the diverse geological record include the differing geometry of eastern and western ISB coasts, time‐transgressive ice retreat, and differential land rebound effects as a result of forebulge collapse and neotectonics. Poor geochronometric control on ice sheet events has not helped the correlation of ISB events with glacial and climatic events elsewhere. Future investigations of glacial sites around the ISB should use an integrated methodological approach involving a range of geomorphological, sedimentary and biofacies data, and dating control where possible. This will help in developing a more precise and holistic late Devensian glacial model that is constrained rigorously by field geological evidence. Copyright © 2001 John Wiley & Sons, Ltd.     

内蒙古大青山-色尔腾山地区什那干群的质疑

在大青山和色尔腾山地区进行地质调查时，在原来划为震旦系什那干群的地层中发现了大量确切的寒武纪化石，特别是大青山地区，在紧邻不整合面处就发现了早寒武世的三叶虫化石。因此该套地层应为下寒武统色麻沟组，而并非震旦系什那干群。同时在对色尔腾山地区震旦系什那干群进行厘定后，提出内蒙古自治区大青山和色尔腾山地区缺失震旦系沉积。这一认识将对内蒙古自治区中部的区域构造演化阶段的划分和地壳演变规律的研究具有指导意义。     

Upper Famennian and Lower Tournaisian sections of the Moravian Karst (Moravo‐Silesian Zone,Czech Republic): a proposed key area for correlation of the conodont and foraminiferal zonations

Foraminiferal and conodont faunas at the Devonian–Carboniferous (D–C) boundary in the southern part of the Moravian Karst (Czech Republic) were studied in different facies of the basin slope. The joint presence of foraminifers and conodonts in calciturbidites along with a positive δ¹³C excursion of the Hangenberg anoxic event enabled the high‐resolution calibration of the late Famennian–early Tournaisian interval (Upper expansa–crenulata conodont zones). The conodont stratigraphic and biofacies succession reveals a strong correlation with other European areas. The Siphonodella sulcata morphotype (close to Group 1 sensu Kaiser and Corradini and “nov. gen. nov. sp. 1” sensu Tragelehn) enters prior to the Hangenberg Event, which resembles Upper and Uppermost Famennian conodont successions from Franconia, Bavaria and Morocco. The diversification of the early siphonodellids takes place after the Hangenberg Event and after the protognathodid radiation. In terms of foraminiferal biostratigraphy, the D–C boundary interval is characterized by the first appearance datum (FAD) of Tournayellina pseudobeata close below the D–C boundary followed by a sequence of Tournaisian bioevents, where apart from the last appearance datums (LADs) of quasiendothyrs, the FADs of the Neoseptaglomospiranella species and chernyshinellids play an important role in a similar manner as in Eastern Europe. The correlation of these bioevents elsewhere is often hindered by glacioeustatically‐driven unconformities and widespread occurrences of unfavourable facies for plurilocular foraminifers (Malevka beds and Bisphaera beds). Copyright © 2013 John Wiley & Sons, Ltd.