A new iguanodontid (Jinzhousaurus yangi gen. et sp. nov.) from the Yixian Formation of western Liaoning, China

A new iguanodontid,Jinzhousaurus yangi gen. et sp. nov., is erected based on the cranial and dental morphology of a specimen from the Yixian Formation of western Liaoning. Although a few primitive characteristics remain,Jinzhousaurus yangi display a number of characteristics similar to those seen in derived iguanodontids. Other interesting characteristics include the absence of antorbital fenestra and the frontal excluded from the participation in orbit, which are closer to the condition in hadrosaurids. The unusual combination of the characteristics provides important data for assessing morphological evolution toward hadrosaurs. The new discovery also represents the first reported large-sized dinosaur from Jehol fauna in western Liaoning, and increases the diversity of this famous fauna. Furthermore, the discovery of a derived iguanodontid from the Yixian Formation provides further evidence supporting a Cretaceous age of the Jehol fauna, which is consistent with an isotopic age.     

A new family of primitive mammal from the Mesozoic of western Liaoning, China

A fairly well-preserved specimen of a new primitive mammal, Repenomamus robustus gen. et sp. nov., has been described from the Yixian Formation (Lower Cretaceous), western Liaoning, China. This animal has several derived characteristics, such as well-developed den-tary/squamosal articulation, reduced number of tooth, differentiation of premolars and molars in postcanine teeth, presence of a dorsal process of the premaxilla that is not in contact with the nasal, closed medial wall of the orbit, and presence of fingerlike promontorium on the petrosal. It also retains some primitive reptile-like features. It is the most primitive taxon among the three mammals known from the Jehol Biota, and also represents the largest mammal of Mesozoic age over the world.     

Earliest Asian discoglossid frog from western Liaoning

Based on a superbly preserved skeleton, a new anuran taxon has been named and described from the Yixian Formation (Upper Jurassic/Lower Cretaceous), Liaoning Province, northeastern China. This discovery documents the first discoglossid fossil from China, the earliest record of the group in Asia, and the only second Mesozoic discoglossid known from fully articulated material in the world. The family Discoglossidae is widely perceived as a primitive anuran group, but has no definite fossils found in collaboration with their recent distribution in Asia. The new discovery from Liaoning extends the temporal range of the group in Asia back at least 120 million years, and provides valuable fossil material for study of anatomical details of early discoglossids, as well as of historical distribution of this primitive anuran group.     

松辽盆地东部构造带白垩系沉积特征研究

松辽盆地东部构造带由于受构造抬升运动和构造反转作用影响明显,白垩系盖层沉积厚度较薄局部剥蚀严重,综合石油地质条件较差。随着区内南部榆树断陷、梨树断陷、德惠断陷等一系列断陷油气勘探取得成功以及北部绥化断陷发育良好的生储盖组合,表明松辽盆地东部赋存丰富的油气资源,但目前缺乏对东部构造带白垩系盖层沉积特征和沉积相演化系统而全面的研究,使得东部构造带整体的油气勘探和资源评估存在较大制约。本文主要通过精细的野外剖面测量并结合钻井资料和前人的研究成果,对松辽盆地东部构造带白垩纪时期与五个构造演化阶段相对应的沉积物特征研究,从而全面掌握了东部构造带白垩系沉积特征和沉积相演化规律。     

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.     

湖盆浅水三角洲形成发育与实例分析

通过总结浅水三角洲沉积特征,结合库车坳陷克拉苏冲断带白垩系巴什基奇克组浅水三角洲的研究,对浅水三角洲特征及其分类方案进行探讨。结果表明:根据不同的供源体系可将浅水三角洲划分为浅水扇三角洲、浅水辫状河三角洲及浅水曲流河三角洲;浅水三角洲的发育需要稳定的构造背景、盆广坡缓、古水体浅、湖平面升降旋回变化、气候适宜、砂质底载荷河流供源充足等有利地质条件;浅水三角洲具有粒度粗、沉积水动力强的沉积特点,单砂体薄、复合砂体厚度大、分布面积广,发育分流河道、河口坝难以保留,垂向上相序不连续、缺乏传统三角洲三层式结构等特征。实例研究表明:库车坳陷巴什基奇克组属浅水辫状河三角洲,其成分成熟度较低、结构成熟度中等偏低,发育交错层理等强水动力沉积构造和间断正韵律,水下分流河道改道频繁、砂体纵横叠置、厚度大、延伸远,有利于构成岩性油气藏。     

Early Paleogene brackish-water molluscs from the Caballas Formation of the East Pisco Basin (Southern Peru)

ABSTRACT

Shell beds from the Caballas Formation in the East Pisco Basin of southern Peru have yielded an assemblage of molluscs numerically dominated by oysters and cerithioid and eulimid gastropods, with lesser numbers of neritid, ampullinid, and pyramidelloid gastropods and noetiid, mytilid, anomiid, and cardiid bivalves. The shell beds mark a transition from continental to marine-influenced environments. Palaeontological evidence, including plant twig moulds on the attachment scars of oysters and a high diversity of potamidid gastropods, is consistent with an interpretation of a brackish-water setting. The majority of molluscan species from the Caballas Formation show a close affinity with Late Cretaceous species from northern Peru, but no unequivocally Cretaceous invertebrate taxa (e.g. ammonites, rudists) have been found. A morphologically distinctive bivalve species that occurs in the Caballas Formation, Carolia (Parinomya) parinensis, only occurs elsewhere in the upper lower Eocene Pariñas and Chacra formations of the Talara Basin of northern Peru. Moreover, several other Caballas Formation molluscan taxa closely resemble early Eocene species from the Talara Basin. These equivocal biostratigraphic data indicate an early Paleogene age as most likely for the Caballas Formation.

http://www.zoobnk.org/urn:lsid:zoobank.org:author:25E21A31-0230-48C7-A2ED-A48A98A3F231     

苏北盆地泰州组原油中芴系列的特征与意义

 苏北盆地是中国东部唯一发现的上白垩统自生自储工业油藏的盆地。通过分析上白垩统泰州组20个油砂和1个原油样品芳烃化合物,发现芳烃馏分以三芳甾烷系列为主,指示母质沉积水体咸化和原油低成熟。来源于高等植物的生物标志物丰度低,反映原油母质以腐泥型为主。芳烃各组分相对含量、三芴系列相对含量和比值、二苯并噻吩/菲等参数反映了原油母质总体形成于强还原的咸水环境,不同地区的还原性存在差异。海安凹陷和高邮凹陷北坡的泰州组原油同属一族群,而吴堡低凸起泰州组原油属于另一族群。利用甲基二苯并噻吩比值换算的镜质组反射率（R_o）,推测海安凹陷泰州组原油来源于泰州组未-低熟烃源灶,高邮凹陷北坡的泰州组原油来源于就近泰州组的低熟烃源灶,而吴堡低凸起泰州组原油来源于邻区高邮深凹成熟的阜宁组烃源灶。研究结果对指导油气勘探具有实际意义。     

塔里木盆地亚格列木组储层特征及控制因素

塔里木盆地雅克拉地区白垩系亚榕列木组是一套以岩屑长石砂岩、长石岩屑砂岩为主的地层.通过对亚格列木组储层薄片观察及物性资料分析发现,储集空间主要为扩大粒间溶孔、粒内溶孔、原生粒间孔,储层类型为低孔中渗储层.亚格列木组储层均表现为强的层内、层间及平面非均质性.储层发育受沉积微相、成岩作用和黏土杂基的影响,沉积微相是储层形成...     

鄂尔多斯沙漠高原白垩系地下水锶同位素的演化机理

结合地下水化学资料,应用含水介质和地下水Sr含量及87Sr/86Sr比值,对鄂尔多斯沙漠高原白垩系含水层中水-岩作用机制进行了研究.结果表明:含水介质中钾长石、斜长石和碳酸盐矿物的87Sr/86Sr比值具有差异,地下水87Sr/86Sr比值介于0.709 871～0.711 792.地下水Sr来源主要为碳酸盐矿物、硫酸...