准噶尔盆地南缘上侏罗统-下白垩统地层不整合成因和构造演化意义——齐古断褶带剖面的启示

为了深化准噶尔盆地南缘新生代前构造演化研究,以准噶尔盆地南缘山前齐古断褶带上侏罗统-下白垩统露头剖面为例,利用野外地质调查、二维地震剖面解释、无人机航拍建模,分析上侏罗统和下白垩统地层之间地层接触关系,结合重矿物不稳定系数和地层厚度分布,得出区域不整合的成因,建立准噶尔盆地南缘山前晚侏罗世-早白垩世构造演化模式.结果表...     

Sinobaatar gen. Nov.: First multituberculate from the Jehol Biota of Liaoning, Northeast China

A multituberculate skeleton from the Lower Cretaceous Yixian Formation at Dawangzhangzi, Lingyuan City, Liaoning Province, Northeast China, provides new morphological information for early multituberculates. The specimen is the holotype of Sinobaatar lingyuanensis gen. et sp. nov. It has a narrow skull that lacks the superorbital crest or postorbital process. The dental formula is 3·?·5·2/1·0·3·2. The dental morphology, especially that of cheek teeth, of S. lingyuanensis is similar to that of Eobaatar, which places it in the family Eobaataridae. The postcranial skeleton of Sinobaatar is similar to that of other multituberculates. As in Holotheria, Metatarsal V of Sinobaatar articulates only with the cuboid and has no contact with the calcaneus, which probably represents the primitive condition of multituberculates. Nine carpals of Sinobaatar resemble those of Zhangheotherium, except the centrale being larger than the trapezoid. The dental features of Sinobaatar show again that eobaatarids are obviously intermediate between Late Jurassic multituberculates and the later forms. Because eobaatarids are only known from the Early Cretaceous, the finding of Sinobaatar, therefore, supports that the age of the Jehol Biota is most likely Early Cretaceous.     

Dinosaur diversity during the transition between the middle and late parts of the Late Cretaceous in eastern Shandong Province, China: Evidence from dinosaur eggshells

The record of dinosaur eggs from the Upper Cretaceous Wangshi Group in eastem Shandong Province, China shows that the dinosaur species represented by elongatoolithids were present from the middle to the late Late Cretaceous, whereas those repre- sented by the dictyoolithids and spheroolithids became extinct in the middle Late Cretaceous and the new species represented by ovaloolithids appeared in the late Late Cretaceous. Estimated eggshell conductance of water vapor is over 4 to over 115 times higher in spheroolithids and the dictyoolithids than in elongatoolithids and ovaloolithids, indicating that eggs of the first two oofamilies required higher humidity during incubation. Based on the δ^18O record as preserved in eggshell, a change from relatively humid to relatively dry climatic conditions can be assumed to have taken place during the transition between the middle and late parts of the Late Cretaceous. It is reasonable to suggest that the change in climate was the cause of the dinosaur diversity.     

四川盆地晚侏罗世蜥脚类一新种

文章记述了在四川盆地上侏罗统上沙溪庙组采到的一批巨型蜥脚类恐龙化石新材料,建立了一新种——井研马门溪龙（Ｍａｍｅｎ－ｃｈｉｓａｕｒｕｓｊｉｎｇｙａｎｅｎｓｉｓｓｐ．ｎｏｖ．）。新种的发现进一步证明马门溪龙属（ＭａｍｅｎｃｈｉｓａｕｒｕｓＹｏｕｎｇ,１９５４）及马门溪龙科（ＭａｍｅｎｃｈｉｓａｕｒｉｄａｅＹｏｕｎｇｅｔＣｈａｏ,１９７２）的分类位置应归勺齿蜥龙超科（Ｂｏｔｈｒｏｓａｕｒｏ－ｐｏｄｏｉｄｅａＹｏｕｎｇ,１９５８）。     

郯庐断裂(K2-E)的伸展活动及其对合肥盆地的控制

郯庐断裂带于晚白垩世 -老第三纪 (K2 -E)时期卷入了广泛的伸展活动 ,其伸展结果是沿着早期先存的走滑断裂产生了伸展正断层 ,构成了合肥盆地的东缘断陷边界。在断裂的西侧控制了合肥盆地上白垩统 -下第三系的同沉积可容空间 ,而断裂东侧张八岭隆起进一步抬升 ,由此形成合肥盆地充填的物源系统。与此同时 ,盆地内先存近东西向逆断层也相应产生了伸展活动 ,并控制了盆内近东西向的沉积。在伸展断陷盆地内均有明显的沉积响应。文章从合肥盆地 K2 -E的沉积响应特征探讨郯庐断裂带伸展期对合肥盆地的控制机理 ,提出了该阶段盆地的沉积可容空间受双向伸展断裂的控制模式     

The Jurassic-Cretaceous transition of Southern Sweden—palynological and sedimentological interpretation

Palynological studies on the Vitab?ck Clay help resolve the position of the Jurassic-Cretaceous boundary in southern Sweden. Well-preserved assemblages of terrestrial pollen and spores, together with abundant algae (Botryococcus), and for the first time, dinoflagellates have been identified in the Vitab?ck Clay. A Berriasian age is corroborated for the Vitab?ck Clay based on the palynological data; the Jurassic-Cretaceous boundary being placed around the contact of this unit with the underlying “Nytorp Sand”. The terrestrial vegetation was dominated by coniferous forest with an understorey of ferns in a warm, temperate climate. The palynoflora shows compositional similarities to the Northern Chinese Floral Province and especially the Jehol Group. The majority of the Vitab?ck Clay represents a moderate-to low-energy paralic succession. However, the basal part of the unit incorporates anomalously coarse material of mixed terrestrial and marine origin. This sedimentary package is herein interpreted to represent tsunami deposits and is similar to coeval tsunami-related deposits in France.     

辽西冀北晚中生代的化石蜥蜴类(爬行纲:有鳞目)

个蜥矢部部龙趾大具有辽西冀北晚中生代已记录的蜥蜴类化石共4属5种,及2个未命名属种。这些化石自下而上可划分4蜴类化石带：中侏罗世杨氏矢部龙带(Yabeinosaurus youngi Zone)、早白垩世早期长趾大凌河蜥-细小龙组合带(Dalinghosaurus longidigitus-Yabeinosaurus tenuis Assemblage Zone)、早白垩世早期细小矢带(Yabeinosaurus tenuis Zone)及早白垩世晚期炭德氏蜥带(Teilhardosaurus canbonarius Zone)凌河蜥-细小矢部龙组合带中的蜥蜴类属种最为丰富且分布较广,为研究早期蜥蜴类的地理地史分重要价值。布长等     

内蒙古中部早白垩世钾玄岩的发现及其意义

内蒙古四子王旗地区发现含有深源捕虏体的富钾玄武岩。玄武岩为黑色致密块状 ,以富碱 (w(K2 O) +w(Na2. O) >5 % )、高钾 (w(K2 O)在 2 . 5 0 %～ 3 .19%之间 )和较高的钛含量 (w(TiO2 )在2 .0 3%～ 2 . 71%之间 )为特征 ,岩石分类上属钾玄岩系列 ,全岩K Ar表观年龄为 10 8～ 12 8Ma ,为早白垩世。古亚洲洋闭合后华北板块在早中生代经历了由强烈的陆内挤压缩短作用转入造山后伸展作用阶段。早白垩世晚期该区受太平洋板块和印度洋板块俯冲作用影响 ,华北板块再次转入挤压作用阶段 ,开始了滨太平洋域的演化。内蒙古四子王旗地处华北板块与西伯利亚板块结合部 ,本次发现的早白垩世钾玄岩系列对于研究华北板块北缘在中生代构造转化中的物质及深部构造演化具有重要意义。     

The Jurassic-Cretaceous transition of Southern Sweden—palynological and sedimentological interpretation

Palynological studies on the Vitab?ck Clay help resolve the position of the Jurassic-Cretaceous boundary in southern Sweden. Well-preserved assemblages of terrestrial pollen and spores, together with abundant algae (Botryococcus), and for the first time, dinoflagellates have been identified in the Vitab?ck Clay. A Berriasian age is corroborated for the Vitab?ck Clay based on the palynological data; the Jurassic-Cretaceous boundary being placed around the contact of this unit with the underlying “Nytorp Sand”. The terrestrial vegetation was dominated by coniferous forest with an understorey of ferns in a warm, temperate climate. The palynoflora shows compositional similarities to the Northern Chinese Floral Province and especially the Jehol Group. The majority of the Vitab?ck Clay represents a moderate-to low-energy paralic succession. However, the basal part of the unit incorporates anomalously coarse material of mixed terrestrial and marine origin. This sedimentary package is herein interpreted to represent tsunami deposits and is similar to coeval tsunami-related deposits in France.