塔中16井区晚奥陶世良里塔格组的沉积相

塔里木板块中央隆起区的塔中低隆带上奥陶统凯迪阶良里塔格组礁相群落是晚奥陶世生物礁演化阶段的例证。该组分为5个岩性段。塔中16井区位于塔中Ⅰ号断裂坡折带向台地内部延伸的缓坡区,海水深度和水流能量显著控制碳酸盐岩的岩相分布。良里塔格组所赋存的典型动物格架礁集中于台地边缘的高能区,而塔中16井区不属于大型动物格架礁建造的富集区域,其早期多以低能带沉积为主,特别是塔中16井和塔中166井灰泥坪常见;晚期常见高能滩相和灰泥丘以及近礁沉积,可划归为台缘坡折带大型格架礁建造向台内的延伸区,这里的水深和能量变化更频繁。偏西北的井在良二段沉积之后抬升较早,东南的塔中161井则保存部分良一段沉积。     

塔里木塔中油田上奥陶统良里塔格组滩相

塔里木板块塔中井区上奥陶统凯迪阶良里塔格组的沉积序列由碳酸盐岩台地区礁滩复合体灰岩构成,显示晚奥陶世由高生物多样性形成的暖水浅海域生态组合。根据滩相灰岩的颗粒组成,可次分为生屑为主、生屑-内碎屑混合、内碎屑为主的三大类型,其中灰泥充填和亮晶方解石胶结均有。部分滩相是礁相单元的近源沉积,而内碎屑和生屑经各种营力改造后多以不同比例混合独立形成滩相。滩中的颗粒粒径一般多小于厘米级,仅部分核形石、珊瑚等颗粒可达到砾级,这些滩多堆积于最大风暴浪基面之上的深度。     

新疆塔里木塔中井区上奥陶统良里塔格组的生物绑结岩

塔里木板块塔中井区上奥陶统凯迪阶良里塔格组灰岩中底栖固着型的钙质微生物、钙藻以及动物苔藓虫、珊瑚、层孔虫,可通过障积、盖覆和粘结等方式形成多种类型的生物绑结岩。对15口井部分岩芯以常用的绑结岩分类方案作岩石学微相分析,并描记底栖固着型生物颗粒的形成特征。菌藻类可在内碎屑表面以包结方式形成粘结岩;钙藻,特别是分枝状钙藻可形成障积岩;层孔虫可被隐藻层纹包结,也可单独形成小型盖覆岩;床板珊瑚格架岩可大量障积生屑和灰泥基质;苔藓虫在动物格架岩比例上占优,可与菌藻类粘结岩互相包结生长,也可独立形成局部小型障积岩。对比巴楚露头区同期藻丘中的绑结岩特征,显示塔中良里塔格组代表晚奥陶世由高生物多样性形成的礁滩复合体生态群落。     

Discovery of a Late Ordovician Foliomena fauna in the Tarim desert,Northwest China

A Foliomena fauna is reported for the first time from the Tarim paleoplate, and stratigraphically from the Yinpingshan Formation (upper Katian, Upper Ordovician) of Querqueke, Kuruktag region, northeastern Tarim, southern Xinjiang, Northwest China. The fauna includes seven species of brachiopods, amongst which three are new and four indeterminate: Anomaloglossa? sp., Orbiculoidea? sp., Foliomena xinjiangensis n. sp., Sericoidea minuta n. sp., Kassinella tarimensis n. sp., Rostricellula? sp., and Anazyga? sp. These species formed a Sericoidea-Kassinella Association, characterized by very small and well-preserved brachiopods, and well-developed laminations in its hosted mudstone, indicating a deep water environment (corresponding to lower BA5 to BA6). The faunal and sedimentological features suggest its affinity to the typical Foliomena faunal group of deep water origin. Numerical analyses show that the Foliomena fauna in late Katian time differentiated into two major paleogeographically related groups, and the Tarim association has a close faunal affinity to the representatives of this fauna in South China, indicating an active faunal exchange between Tarim and South China before the end-Ordovician mass extinction.     

塔里木板块塔中区上奥陶统良里塔格组的生物礁类型

塔里木板块塔中Ⅰ号坡折带附近上奥陶统良里塔格组取芯井段中可识别多种生物礁灰岩类型,包括珊瑚骨架/障积岩、海绵骨架/绑结岩、苔藓虫绑结岩、钙藻障积岩、钙质菌藻障积/绑结岩等礁灰岩类,藉此可归纳出珊瑚礁、珊瑚-钙藻礁、层孔虫礁、层孔虫-钙藻礁、珊瑚-层孔虫-钙藻礁、苔藓虫礁丘、钙藻礁丘、灰泥丘和微生物礁等生物建造单元。这些礁体的时空分布模式与古环境分异相关联,纵向上具有灰泥丘向珊瑚-层孔虫-钙藻礁至苔藓虫礁丘和钙藻礁的群落结构更替趋势;空间分布则向台地北缘,即I号坡折带延伸显示由低能带灰泥丘向高能带珊瑚-层孔虫-钙藻礁的相变,而且高能带珊瑚-层孔虫-钙藻主体礁和环其周缘相对低能带的钙藻礁丘、灰泥丘等在一定范围内构成造礁群落结构分异。     

新疆塔里木盆地中部和北部台地上奥陶统良里塔格组岩心中的泡孔目、隐口目和窗孔目苔虫

新疆塔里木盆地奥陶系良里塔格组礁滩相非常发育,部分地区泡孔目、隐口目和窗孔目苔虫化石非常丰富,本文首次系统描述了塔里木盆地巴楚-塔中和塔北碳酸盐台地部分取心井上奥陶统良里塔格组的泡孔目、隐口目和窗孔目苔虫7科11属13种,包括1个新种和6个未定种,分别为Lunaferamita nevadensis Utgaard,L. vesicu-larissp.nov.,L.sp.,Graptodictya meneghinii(Vinassa de Regny),Chazydictya sp.,Rhinidictya nicholsoni Ulrich,Metadictyacf.crassa(Hall),Trigonodictya acuta(Hall),Stictoporella sp.,Chasmatopora spatiosa Ariun-chimeg,Ralfinellasp.,Moyerella sp.,Moorephylloporina sp.。其中,隐口目细枝状的Rhinidictya和网状的Chasmatopora,Moorephylloporina在塔中和巴楚地区横向及纵向地层中分布非常广泛。     

Upper Ordovician bryozoans from the Xiazhen Formation of Yushan,northeastern Jiangxi,East China

The bryozoan fauna from the Xiazhen Formation (Katian, Upper Ordovician) of northeast Jiangxi Province, southeast China is reported here. Seventeen species of bryozoans belonging to fifteen genera and four orders are identified: Homotrypa yushanensis, Homotrypa sp., Prasopora yushanensis, Trematopora sp., Monotrypella sp., Rhombotrypa sp., Orbignyella sp., Constellaria jiangxiensis, Constellaria sp., Stictopora nicholsoni, Trigonodictya parvula, Ptilodictya ensiformis, Stictoporella sp., Pseudopachydictya sp., Nematopora sp., Arthrostylidae sp. indet., and Chasmatoporidae sp. indet. Four of these genera have been reported previously but nine genera (Trematopora, Monotrypella, Rhombotrypa, Orbignyella, Trigonodictya, Ptilodictya, Stictoporella, Pseudopachydictya, and Nematopora), one rhabdomesine and one fenestrate are found for the first time in the Late Ordovician strata of South China. Our palaeogeographical analysis suggests that the bryozoan association is typical for the Katian, which is mostly widespread in Laurentia, Siberia, Baltica and Mediterranean, and displays palaeobiogeographical relationships to the Laurentia–Siberia Province.     

塔里木板块古城4井中奥陶统一间房组的海进序列

塔里木板块中央隆起区奥陶系碳酸盐岩台地东南缘的古城4井钻遇约130m厚的中奥陶统达瑞威尔阶一间房组灰岩。该组下部为表附藻-肾形钙藻-瓶筐石礁丘群落,间夹有薄层砂屑滩,海水深度推测位于10-30m的潮下带至正常波浪带之间;上部为中-低能带藻屑砂屑组合,灰泥含量增高,大致指示正常波浪带之下到最大浪基面之间30-60m的深度。古城4井与中央隆起区西北部巴楚露头区同期沉积均显示海水逐渐加深的过程,到上奥陶统桑比阶吐木休克组沉积期两地都达到了奥陶系的最大海泛面。     

Internal structure and paleoecology of the lower Permian Uzunbulak reef complex of the Tarim Basin,Northwest China

Summary The internal construction and biotic communities of the Uzunbulak reef of the northwestern Tarim Basin are studied for the first time. The reef was built during the Sakmarian, while the reef substrate and capping beds are of latest Asselian and earliest Artinskian ages, respectively. The reef substrate beds are composed of skeletal and oncoid grainstone. Those fusulinid-dominated skeletal shoals and oncoid banks indicate a high-energy environment and produced local topographic highs on which the reef grew. Reef framework consists mainly of calcisponge bafflestone, calcisponge-Thartharella framestone, and Tubiphytes, Archaeolithoporella and Girvanella boundstones. Calcisponges were the primary frameconstructors that baffled high-energy currents. Archaeolithoporella, Tubiphytes, Girvanella and possibly microbes acted as the primary binders for the boundstone framework. Fusulinids and brachiopods were common reef dwellers. The interreef facies sediments are composed of skeletal-crinoid wackestone-packstone. Most of bioclasts have thick, micritized envelopes. The back-reef facies deposits consist of alternating skeletal packstone to wackestone and black shale. Sea-level fluctuations were probably accountable for the reef growth and demise. Of the reefal dwellers, brachiopods are extraordinarily abundant in Uzunbulak. They are assignable to five distinctive associations, one each from the reef substrate, framework and inter-reef facies, respectively, and two from the reef capping facies. The brachiopods in the substrate beds were mostly attached to hard substrates by a pedicle, while a few species rested on soft substrates by support of halteroid spines. Cementation of the ventral valve on hard substrates characterizes attachment of the reef framework brachiopods. All inter-reef species were anchored into the substratum comprising hard material by a strong pedicle. Back-reef brachiopods dominantly rested on the soft substrates by support of halteroid spines. the framework brachiopods had the strongest wave-resistant capability;those from both substrate and inter-reef facies were moderately capable of withstanding agitation; and the backreef species preferred to live in calmwater, organic-rich muddy environments.     

The base of the Middle Ordovician in China with special reference to the succession at Hengtang near Jiangshan, Zhejiang Province, southern China

Extensive work during the last decade has led to the recent decision by the International Subcommission on Ordovician Stratigraphy that the base of the Middle Ordovician Series should be placed at the base of the Baltoniodus triangularis Conodont Biozone in the Huanghuachang GSSP (Global Stratotype Section and Point) section near Yichang, Hubei Province, China. A review of the biostratigraphy of successions in many parts of China shows that for various reasons, it is currently difficult to recognize the precise boundary level in many regions, and additional studies are clearly needed. A newly exposed, previously poorly known, condensed section in deeperwater facies at Hengtang near Jiangshan in the Chiangnan (Jiangnan) belt has yielded a substantial number of important graptolites and conodonts through the boundary interval. It provides a more informative illustration of the relations between the ranges of several key taxa of these groups than any other section in China, and the level of the base of the Middle Ordovician appears to be within an about 1.8 m thick interval of Ningkuo Formation, and lies in the lower Isograptus caduceus imitatus Biozone.     

Facies development of a Late Ordovician mixed carbonate-siliciclastic ramp proximal to the developing Taconic orogen: Lourdes Formation, Newfoundland, Canada

The Upper Ordovician (late Whiterockian to Mohawkian) Lourdes Formation represents a narrow (tens of kilometers), short-lived [∼5–7 million years (my)], open-ocean (high-energy) mixed siliciclastic-carbonate ramp that onlapped allochthonous strata along the orogen side of the local Taconic foreland basin. Platform development followed a 6–8 my hiatus during which weathering had concentrated chemically mature siliciclastics that were admixed with initial carbonate sediments. A cross-platform facies gradient contains paleokarst and peritidal carbonates and sandstones, shallow-ramp carbonate bioherms and skeletal shoals, and deeper ramp calcareous shales. Transgressive systems tracts are marked by ramp-wide sheets and shoals of skeletal grainstone and low accumulation rates, and highstand systems tracts are marked by significant admixture and interbedding of siliciclastics with cross-ramp carbonate facies. Platform demise coincides with increased siliciclastic input, which is likely tectonically influenced. The Lourdes platform is equivalent to epicontinental foreland ramps along eastern Laurentia, but its narrower width precluded formation of oceanographically restricted platform-interior facies.     

Cincinnetina,a new Late Ordovician dalmanellid brachiopod from the Cincinnati type area,USA: implications for the evolution and palaeogeography of the epicontinental fauna of Laurentia

Abstract: The most common forms of Late Ordovician dalmanellid brachiopods from the Cincinnatian type area, previously treated as either Dalmanella or Onniella, are assigned to Cincinnetina gen. nov. The new genus differs from Dalmanella and Onniella in having a consistently developed primary medial costa in the dorsal valve, a larger cardinal process that tends to develop a trilobed myophore, strongly differentiated fine and coarse punctae, and sparse aditicules. Cincinnetina can be distinguished from the closely related Paucicrura and Diceromyonia in its smaller trilobed cardinal process (when developed) that does not have a dominant medial lobe and does not extend into the delthyrial cavity of the ventral valve. Globally, Dalmanella and Onniella occur most commonly in deposits of relatively deep‐ or cool‐water palaeoecological settings, whereas in North America, Cincinnetina, Paucicrura and Diceromyonia are found mainly in carbonate‐rich deposits in warm‐water depositional environments, with Cincinnetina and Paucicrura most common in pericratonic settings and Diceromyonia in palaeoequatorial inland seas.     

Age constraints of the Hungshihyen Formation (Early to Middle Ordovician) on the western margin of the Yangtze Platform,South China: New insights from chitinozoans

The Hungshihyen Formation represents the Lower to Middle Ordovician near-shore siliciclastic deposits on the western margin of the Yangtze Platform, South China. However, its age is still debated, largely because of insufficient studies. Here we documented the Bursachitina maotaiensis–B. qianbeiensis chitinozoan assemblage from the lower part of the Hungshihyen Formation at Songliang, Qiaojia County, eastern Yunnan Province. This assemblage is remarkably similar to an assemblage that roughly correlates to the middle part of the Corymobograptus deflexus graptolite Biozone in northern Guizhou Province, indicating that the Hungshihyen Formation at Songliang is probably of late Floian age and may extend into the early Dapingian. Additionally, a revision on the chitinozoans previously documented from the strata assigned to the same formation in the Wuding area was made according to the latest classification. The revision allows the recognition of the Euconochitina symmetrica–Eremochitina brevis assemblage, and therefore suggests a late Tremadocian age for this interval based on regional and global chitinozoan biostratigraphic correlations. Considering also its lithologic succession, we argue that the chitinozoan-bearing strata in the Wuding area previously assigned to the Hungshihyen Formation correspond most likely to the uppermost part of the underlying Tangchi Formation or the lowermost part of the Hungshihyen Formation. The base of the Hungshihyen Formation appears therefore to be diachronous in eastern Yunnan Province.     

First evidence of an ankylosaur (Dinosauria,Ornithischia) from the Jurassic Qigu Formation (Junggar Basin,NW China) and the early fossil record of Ankylosauria

The first evidence of an ankylosaur from the Late Jurassic Qigu Formation of the southern Junggar Basin (Xinjiang, northwestern China) is described, based on an isolated caudal vertebra that was discovered together with fragmentary remains of other dinosaurs, including stegosaurs, sauropods, and theropods. The caudal vertebra is characterized by the following features: (i) elliptical morphology of the centrum, being wider than high; (ii) short antero-posterior length of the centrum; (iii) pronounced transversely extending ventral groove; (iv) massive transverse process, that is longer than the centrum diameter; (v) transverse process meeting the centrum high at the dorsal half and at a relatively flat angle; (vi) transverse process making a broad contact with the neural arch without forming a proximo-dorsal projection; and (vii) notochordal prominence present in the centre of the anterior articular surface. The study specimen represents only the second record of an ankylosaur from the Jurassic of Asia — aside from the slightly older Tianchisaurus from the early Upper Jurassic Toutunhe Formation, equally from the Junggar Basin. It helps to fill a gap in our knowledge of the early evolution of these armoured dinosaurs. Additionally, this discovery highlights the potential of the southern Junggar Basin to yield a rich vertebrate fauna and thus to provide an important insight into Late Jurassic ecosystems of Central Asia.     

A new oospecies of Similifaveoloolithidae from the Xiuning Basin,Late Cretaceous of Anhui,China

Well-preserved dinosaur eggs from the Cretaceous Huizhou Formation in the Xiuning Basin, Anhui Province, China, are analysed in this paper. We describe a new oospecies, Similifaveoloolithus qiyunshanensis, based on several distinct characters of external morphology, size, eggshell thickness, and internal microstructure. Radial sections of this new oospecies show branched eggshell units with a fused layer near the outer surface, while numerous irregular pores and cones constitute a honeycomb pattern in tangential sections. The discovery of S. qiyunshanensis expands the distribution of Similifaveoloolithidae dinosaur eggs in China and provides new fossils for researching dinosaur eggshell formation mechanisms which are different from those of the currently known oofamilies. The dinosaur-egg-bearing strata in the Huizhou Formation have been dated to the early Late Cretaceous (Cenomanian-Turonian) on the basis of a similar dinosaur egg assemblage in the Tiantai Basin in Zhejiang Province. The eggs described in this paper are thought to have been laid in a buried nest while enrichment of trace elements in eggshells may have been caused by their ingestion into the body of the dinosaur producer. We suggest that the paleoclimate of this habitat was semi-arid to arid and that this environment was favourable for the preservation of eggs.http://zoobank.org/LSIDurn:lsid:zoobank.org:pub:9D63A51F-5A4B-4249-901D-42A33E9FA933     

The onset of Late Paleolithic in North China: An integrative review of the Shuidonggou site complex,China

Shuidonggou (SDG) attracts scholars who are interested in Late Paleolithic of China, even east Asia, from generation to generation since 1923 when rich lithic artifacts and animal fossils were discovered at locality 1. During the past almost one century, many excavations have been conducted by different institutes at different localities of SDG. Numerous data has been obtained and tens of thousands of artifacts were yielded. The understanding of nature and context of SDG is increasing gradually with the repeated excavation and in-depth research. The present paper reviewed the formal excavations and achievements in SDG. Especially, a series investigations and excavations since 2002 have been emphasized. After this long-term fieldwork, the geographic range of SDG has extended far beyond the range suggested by previous findings. The presence of discrete cultural horizons at various SDG localities indicate repeated use and occupation of the area by early human groups between 50–10 kya with a gap in LGM. During the repeated occupations, diverse and complex behaviors including gathering various plants, heat treatment preparation for knapping, making ornaments, engraving were identified using different kinds of methods and techniques by scholars. Paleoenvironmental reconstruction based on pollen analysis suggests that late Pleistocene/early Holocene human utilization of the SDG area occurred primarily around 32–24 kya and 13–11 kya when climatic conditions were more favorable. Years of excavations and researches make progress with nature of SDG. However, the issues about Initial Upper Paleolithic assemblages in SDG, origin/disappearance of Levallois-like technology in China are still open to debate. Further excavation and research at SDG1 will clarify these issues.     

雷州半岛灯楼角珊瑚礁的生态特征与资源可持续利用

分布于雷州半岛西南部灯楼角的珊瑚礁,自海向陆可分为6个生态带,已鉴定出现代活石珊瑚(Scleractinia) 13科2 5属39种3未定种。该珊瑚礁位于热带北缘,附近人口密集,它的发育受自然因素和人类活动双重制约。气候方面,近4 2 a来的温度总体上升有利于本区珊瑚礁的发育,而台风活动对本区珊瑚礁可能有负面的影响;人类活动对本区珊瑚礁的影响表现为旅游业的快速发展与保护行动滞后威胁珊瑚礁、渔业和养殖业影响珊瑚礁、作为建筑材料使用而破坏珊瑚礁等3个方面。作为一种重要的海洋生态资源,本区珊瑚礁若得以科学保护,将具有广阔的可持续利用前景     

Systematics and functional morphology of Molarochoerus yuanmouensis (Suidae, Mammalia) from the Late Miocene of Yunnan, China

The discovery of a propotamochoerine suid with unique features of the dentition and skull led to the naming of Molarochoerus yuanmouensis Liu & Pan [6]. Further study of the material reveals that this species was better adapted than Sus scrofa for the ‘rooting’ behaviour and that its dentition has morphological features indicating that it was eating hard food items. The posterior premolars are completely molarised, hence the generic name, the first time that any suid has been shown to possess almost perfectly molariform P4/s and p/4s. In lateral view the curvature of the occlusal surface of the upper cheek teeth is convex ventrally, the opposite of the usual situation in suids. The origins of the rostral musculature are exceptionally well developed, and the nasal bones are much more robust than is usually the case in Suinae, indicating powerful musculature and fortified osseous structures presumably for ‘rooting’ in hard ground or for extended periods of time. The masseteric musculature appears to have been more massive than it is in Sus, Microstonyx and Propotamochoerus. To cite this article: M. Pickford et al., C. R. Palevol 3 (2004).

Résumé

Systématique et morphologie fonctionnelle de Molarochoerus yuanmouensis (Suidae, Mammalia) du Miocène supérieur de Yunnan, Chine. La découverte d”un Suidae Propotamochoerini présentant des caractères dentaires et crâniens uniques a conduit à la création de Molarochoerus yuanmouensis Liu & Pan [6]. Une étude du matériel montre que cette espèce était bien mieux adaptée au fouissage que Sus scrofa. Par ailleurs, les caractères morphologiques de sa dentition indiquent qu'il se nourrissait d'aliments coriaces. Les prémolaires postérieures sont complètement molarisées, d'où le nom générique, et c'est la première fois qu'un Suidae présente des P4 supérieures et inférieures presque parfaitement molariformes. En vue latérale, la courbure de la surface occlusale des dents jugales supérieures est convexe ventralement, différant ainsi de la morphologie classique des Suidae. La musculature rostrale est exceptionnellement bien développée et les os nasaux sont beaucoup plus robustes que chez les autres Suinae, suggérant des structures musculaires et osseuses puissantes, probablement liées au fouissage, soit dans des sols, soit sur une longue durée. Les muscles massétériens sont plus puissants que dans les genres Sus, Microstonyx et Propotamochoerus. Pour citer cet article : M. Pickford et al., C. R. Palevol 3 (2004).