西藏北部永珠地区石炭系永珠组岩石地层和古生物特征

永珠地区位于申扎古生代盆地,区内发育连续的早奥陶世—中二叠世海相沉积序列。石炭系永珠组岩石组合特征为细粒石英砂岩、页岩、粉砂岩,夹多层生物碎屑灰岩,含丰富的生物化石,主要有腕足类、双壳类、牙形刺、珊瑚、苔藓虫、菊石、三叶虫。牙形刺Gnathodusgirtyi—Gnathodustexanus为早石炭世晚期组合;腕足类Productus—Rhipidomellatibetena为早石炭世晚期组合,Choristites—Spirigerella为晚石炭世早期下部组合,Trigonatretacf.paucicostulata—Elivellabaschkirica为晚石炭世早期上部组合。Uncinunellina是典型的冷水习性腕足类,Cyathaxonia是典型的冷水习性珊瑚,表明了全球石炭纪冰期已影响到本区。确定了永珠组的时代为早石炭世晚期—晚石炭世早期,且早石炭世与晚石炭世分界线在第11层与第12层之间。     

海南岛西北部早石炭世褶颊类三叶虫化石的发现及其古生物地层学意义

海南岛西北部白沙县金波老村附近南好组第二段首次发现Australosutura sp.,Conophillipsia sp.,Hunanoproetus sp.,Linguaphillisia sp.,Weberiphillipsia cf. linguiformis Yuan & Li,和Werberiphillipsia sp.等5属6种褶颊类三叶虫,据三叶虫生物地层年代确认,为分布广泛的早石炭世早期的属种。三叶虫化石的发现,不仅扩展了早石炭世三叶虫动物群的地理分布,而且为白沙地区南好组地层年代的修订及与岛内不同地区南好组的地层对比及与岛外同期地层的对比提供了精确的三叶虫生物地层的重要化石材料。     

东秦岭古生代生物古地理

秦岭褶皱带位于华北板块和扬子板块结合部位,其在河南省内的部分多划为东秦岭。东秦岭以商南-镇平缝合带分为东秦岭北部和东秦岭南部。东秦岭古生代生物古地理演变可以划分为6个阶段。在寒武纪至中奥陶世早期,东秦岭北部二郎坪海槽的寒武纪放射虫和早奥陶世牙形石与东秦岭南部淅川陆棚北部的寒武纪三叶虫、早奥陶世牙形石和头足类属华南生物省,而淅川陆棚南部的寒武纪三叶虫和早奥陶世牙形石属于华南生物省,兼有华北生物省分子。在中奥陶世晚期至奥陶纪末,二郎坪海槽的腹足类、头足类和珊瑚与淅川陆棚的牙形石、珊瑚、腕足类、头足类和三叶虫均属华北生物省。在早志留世,二郎坪海槽的珊瑚与淅川陆棚的笔石属华南生物省。在中志留世至早泥盆世,东秦岭未发现古生物化石,很可能为陆地,并与华北陆块联为一体。在中泥盆世至早石炭世,东秦岭北部柿树园海槽与东秦岭南部南湾海槽的孢子及淅川陆棚的晚泥盆世珊瑚、腕足类和古植物及早石炭世蜓属华南生物省。晚石炭世至二叠纪末,柿树园海槽的孢子见于华北生物省,东秦岭南部缺乏海相沉积。总之,在古生代,东秦岭经历了由华南生物省→华北生物省→华南生物省→华北陆→华南生物省→华北生物省6个阶段,组成3个演变旋回。东秦岭北部和南部生物古地理具有明显的演变方向的统一性和演变时间的相似性。     

中国石炭纪三叶虫生物地层

详细介绍了我国石炭纪三叶虫属的地层分布情况 ,首次提出了我国石炭纪 9个三叶虫组合带及其与其他门类化石带的对比关系 ,并扼要地介绍了我国石炭纪 4种不同相区的三叶虫生态群落 ,对深入研究石炭系及建立全球石炭纪年代地层系统具有重要意义     

海南岛保亭县南好地区特列奇期地层层序的厘定

过去报道的来自海南岛南好地区南好组选层型剖面、创名地化石点等处早石炭世腕足类实为志留纪化石。在该组多个化石点发现腕足类、珊瑚、三叶虫及软骨鱼类等化石,这些化石组合指示地质时代为志留纪兰多维列世特列奇中晚期,南好组一名应予废弃。依据岩石组合、基本层序等重新厘定了志留纪足赛岭组地层层序,将足赛岭组划分为4个岩性段,代表志留纪兰多维列世特列奇中晚期的沉积。     

东秦岭古生代古生物区与古地理变迁

本文根据对东秦岭古生代各纪古生物区的分析，指出在北美岭褶皱带，二郎坪海槽寒武纪放射虫和微浮游植物属华南区，奥陶纪头足类，腹足类、珊瑚为华北区，早志留世珊瑚为华南区，柿树园海槽中泥盆世至二叠纪孢子主要见于华南区，干江河海槽泥盆纪珊瑚，海百合为华南区。在南秦岭褶皱带，浙川陆棚寒武纪三叶虫有华北区和华南区的分子，奥陶纪牙形石、头足类由华南区变为华北区，晚奥陶世腕足类、三叶虫、珊瑚为华北区，而早志留世笔石，晚泥盆世珊瑚，腕足类和Ting、古植物以及早石炭世珊瑚和Ting均为华南区，南湾海槽泥盆纪孢子为华南区。在此基础上探讨了东秦岭古生代古地理变迁过程。     

Stratigraphy and facies development of the marine Late Devonian near the Boulongour Reservoir,northwest Xinjiang,China

Late Devonian to Early Carboniferous stratigraphic units within the ‘Zhulumute’ Formation, Hongguleleng Formation (stratotype), ‘Hebukehe’ Formation and the Heishantou Formation near the Boulongour Reservoir in northwestern Xinjiang are fossil-rich. The Hongguleleng and ‘Hebukehe’ formations are biostratigraphically well constrained by microfossils from the latest Frasnian linguiformis to mid-Famennian trachytera conodont biozones. The Hongguleleng Formation (96.8 m) is characterized by bioclastic argillaceous limestones and marls (the dominant facies) intercalated with green spiculitic calcareous shales. It yields abundant and highly diverse faunas of bryozoans, brachiopods and crinoids with subordinate solitary rugose corals, ostracods, trilobites, conodonts and other fish teeth. The succeeding ‘Hebukehe’ Formation (95.7 m) consists of siltstones, mudstones, arenites and intervals of bioclastic limestone (e.g. ‘Blastoid Hill’) and cherts with radiolarians. A diverse ichnofauna, phacopid trilobites, echinoderms (crinoids and blastoids) together with brachiopods, ostracods, bryozoans and rare cephalopods have been collected from this interval. Analysis of geochemical data, microfacies and especially the distribution of marine organisms, which are not described in detail here, but used for facies analysis, indicate a deepening of the depositional environment at the Boulongour Reservoir section. Results presented here concern mainly the sedimentological and stratigraphical context of the investigated section. Additionally, one Late Devonian palaeo-oceanic and biotic event, the Upper Kellwasser Event is recognized near the section base.     

西准噶尔克拉赛勒克山和布克河组晚泥盆世化石的发现及其地层归属

西准噶尔地区广泛分布的和布克河组已被证明是洪古勒楞组的晚出异名,本文在西准噶尔克拉赛勒克山原划为下石炭统"和布克河组"的碎屑岩地层中发现了丰富的动、植物化石,包括:三叶虫Phacops sp.,菊石Manticoceras sp.,腕足类Tylothyris sp.,Aulacella sp.,"Mucrospirifer"sp.,Cyrtospirifer sp.,植物Leptophloeum rhombicum,Syringodendron sp.,Knorria sp.,其时代显示为晚泥盆世。根据岩性组合特征将其厘定为上泥盆统铁列克提组,而非"和布克河组"的替代名称洪古勒楞组。通过区域地质调查工作,证明了西准噶尔玛依力山地层小区内没有洪古勒楞组的分布,其晚泥盆世地层仅由铁列克提组组成,洪古勒楞组只分布在沙尔布尔提山地层小区,两个地层小区的界线为孟布拉克北侧至谢米斯台山南坡的深大断裂。晚泥盆世两个地层小区沉积分异明显,直到早石炭世早期才进入统一的盆地演化阶段,地层小区的分区性也随之消失。     

论海南岛地区志留系

海南岛志留系以往被划分为上、中、下三个统。志留系之上是南好组 ,其层位以往被确定为下石炭统岩关阶 ,并认为它与其下的上志留统足赛岭组呈不整合接触。最近在南好组选层型剖面发现早志留世特里奇期晚期(L ate Telychian)的 Xinanospirifer腕足动物群和三叶虫 L atiproetus cf.latilimbatus (Grabau) ,重新论证了以往被确认为中志留统靠亲山组所产的腕足类、三叶虫和珊瑚化石其实都是特里奇期早至中期的分子。现在以无可争辩的事实证明了久归于下石炭统岩关阶南好组 ,以及其下的、以往被确定为上志留统足赛岭组、中志留统靠亲山组等所谓两个构造层的地层都应改归于下志留统 (L landovery Series)。北区下志留统仅有鲁丹期中期至爱隆期早期的黑色碳质页岩相和泥页岩相沉积 ,未发现任何大化石。南区下志留统发育较全 ,为细至中粗粒碎屑岩相夹碳酸盐岩相沉积 ,产丰富介壳相各门类化石 ;当时该区所生存的动物群与扬子区早志留世的关系非常密切 ,并在早志留世末期与扬子区大部分地区一样上升为陆 ,表明海南岛地区在当时属于扬子地台区范畴。     

Stonehammer Geopark,New Brunswick,Canada

Stonehammer Geopark of New Brunswick, Canada is one of the newest destinations in the UNESCO‐assisted Global Geoparks Network, and the first in North America. Its rocks tell the amazing billion‐year story of the evolution of eastern North America. Highlights include some of the finest Precambrian stromatolites in the world, a Cambrian site that yielded one of the world's largest trilobites, and a Silurian section with a rich fauna of fish, crustaceans and sea scorpions. At the famous ‘Reversing Falls’ in Saint John, visitors can also see the boundary between the Late Precambrian Brookville Terrane and the western part of the Avalon Terrane, and learn about the late Silurian closure of the Iapetus Ocean during the final stages of the accretion of North America. In and around the city, Devonian pebbly sandstones represent the erosive remnants of the highlands formed as a result of that terrane accretion event, and slightly younger Carboniferous exposures further shed light on the evolution of life at a time when the region lay on the equator. These include early Carboniferous clubmoss forests preserved on the main highway east of Saint John, and late Carboniferous deposits rich in the remains of fossil plants, insects, giant arthropods, and some of the earliest reptiles—the latter recorded by spectacular trackways. Scattered Mesozoic outcrops and Quaternary moraines continue the story to the present day. Positioned at the gateway of Atlantic Canada, Stonehammer Geopark is a strategic part of an emerging geotouristic network that also includes UNESCO World Heritage Sites at nearby Misguasha, Quebec (Devonian coastal ecosystems) and Joggins, Nova Scotia (Pennsylvanian fossil forests). It presents a brilliant opportunity to teach visitors of the extraordinary story of Earth's evolution.     

Biodiversity changes of the Ordovician trilobites in the middle Yangtze region of South China

The biodiversity changes of trilobites in the middle Yangtze region of South China in the Great Ordovician Biodiversification Event and the end-Ordovician mass extinction have been analysed. The Ordovician trilobites in this region originated in the early Tremadocian and radiated from the late Floian to the early Katian. Two peaks of diversity appeared in the late Dapingian to the early Darriwilian and the early Katian. The extinction occurred in the late Katian, followed by a survival period in the Hirnantian. The Whiterock fauna began to surpass the Ibex fauna during the early Katian and were dominant by the late Katian to the Hirnantian, indicating that Cambrian Evolutionary Fauna was gradually replaced. The study once again confirms the view that the effects of factors such as sea level, climate, oxygen content, nutrient supply, and tectogenesis differ temporally and to different degrees in different regions, resulting in differences in the vertical sequence and horizontal combination of ecosystems, which is the reason for the different evolution patterns of Ordovician trilobites in different regions.     

论吉林浑江大阳岔寒武、奥陶系的分界

<正> 我国寒武-奥陶系界线的研究在20年代就已涉及(孙云铸,1923),周志毅、张进林(1978)认为我国北方寒武-奥陶系的界线应该划在上寒武统的Mictosaukia orientalis组合与下奥陶统的Onychopyge-Leiostegium组合之间;并且认为这条界线大致可与澳大利亚昆士兰上寒武统Payntonian顶部的Mictosaukia perplexa带与下奥陶统Datsonian底部Cordylodus proavus带之间的界线进行对比。周志毅、王志浩等(1984)根据三叶虫、     

Spirits of Yokokurayama: shrine of the Japanese trilobites

‘We are such stuff as dreams are made on, and our little life is rounded with a sleep’. So sleep the trilobites of Yokokurayama, a sacred mountain hidden within the beautiful landscape of Japan’s Shikoku’s island. And though Prospero may have been speaking to his daughter and her fiancé (in William Shakespeare’s The Tempest), he might well have been contemplating the magnificent trilobite fossils of Yokokurayama. Japan may be better known for its sweeping volcanic landscapes, majestic castles, Shinto shrines and bullet trains, but it is also home to important collections of Silurian and Devonian trilobites.     

滇西保山地块中部寒武纪双地麦群的特征及其时代重新厘定

在进行云南l∶5万板桥幅区域地质调查的过程中,对该区保山地块中前人划分的双麦地群进行了详细研究。结果发现,该区的双麦地群实为一套细碎屑板岩夹大理岩和安山质、玄武质火山岩组合,并在其中首次发现了晚寒武世崮山期Blackwelderia带的三叶虫化石分子Blackwelderia baoshanensis Luo,Blackwelderia sp.,Parashengia elongata Luo等,且具明显的底栖-浮游的混生现象,从而确定该套地层应属寒武系上统核桃坪组,而非寒武系下—中统双麦地群。该套地层岩石组合及其时代的确定,为进一步深入了解保山地块的构造属性、构造单元划分和发展演化提供了新的证据。     

The significance of Cambro-Ordovician trilobites from the Kalladeina 1 drill hole,Warburton Basin,South Australia

The significance of trilobites described from six cores from the Kalladeina 1 drillhole from the Warburton Basin, northeastern South Australia is discussed. The oldest are from a dark grey shale of Core 16 from a depth of 3453.7–3455.8 m; they are of possible early Drumian (Cambrian Series 3, middle Cambrian) age. The youngest come from a dark grey shale of Core 4 at a depth of 2017.2–2022.04 m. This fauna contains the trilobites Asaphellus? sp., Yosimuraspis sp., Conophrys sp. and Protopliomerops? sp. thus indicating a Tremadoc (earliest Ordovician) age. These are the youngest known trilobites from the Warburton Basin and the youngest known in South Australia.     

山东长清、薛城一带中、上寒武统界线新认识

<正> 华北中寒武统与上寒武统界线问题,实际上也涉及崮山组时代的归属问题。国外学者如B.Willis和E.Blackwelder(1907),C.D.Walcott(1913),A.W.Grabau(1924),T.Kobayashi(1935)和R.Endo(1937)等认为崮山组应归中寒武世晚期。1959年由Moore主编的《三叶虫专著》(Treatise on Invertebrade Palaeontology Part O.)将崮     

Remains of trilobites and other species discovered in a volcanic ash bed of the end-Permian,Yangtze craton,South China

The remains of trilobites and other species were unexpectedly discovered in a volcanic ash layer beneath the Permian–Triassic Boundary (PTB). Based on a biostratigraphic investigation of the Zhongliangshan section in Chongqing, South China, the quantity of the species gradually decreased with subsequent volcanism. This finding provides an opportunity to further understand the disappearance of trilobites and the evolution of the mass extinction event. The temporal coincidence between the volcanic eruption event and the loss of trilobites and other species supports the idea of a cause-and-effect relationship. The species remains in the ash bed appeared before the disappearance of Clarkina yini and the climax of the negative carbon isotope excursion, which implies that the onset of the mass extinction occurred at the end-Permian. The explosive volcanic events caused massive releases of CO₂, toxic gases and volcanic ash and resulted in loss of habitat for certain species in the Tethys domain. This phenomenon may have led to the abrupt death of trilobites and the catastrophic collapse of biodiversity.     

Geochemical constraints on Carboniferous volcanic rocks of the Yili Block (Xinjiang,NW China): Implication for the tectonic evolution of Western Tianshan

The Yili Block is important for understanding the Late Paleozoic geodynamic evolution of Central Asia. It is bounded to the north by the Northern Tianshan Carboniferous flysch and ophiolitic mélange. The center of the Block is dominated by Carboniferous sedimentary rocks with intercalation of volcanic rocks. Petrological and geochemical features of these Carboniferous volcanic rocks show that: (1) they belong to the calc-alkaline series, (2) they display prominent Nb–Ta negative anomalies consistent with subduction-related magmas, and (3) HFSE-based discriminations place these volcanic rocks in the field of continental arcs. The depositional evolution of the sedimentary series shows evidence for Carboniferous sedimentation in a basin instead of rifting as previously proposed. All these evidences, together with the occurrence of contemporaneous turbidites and ophiolitic mélange along the northern boundary of the Yili Block, allow us to infer that the northern border of the Yili Block was a continental active margin during the Carboniferous. The Late Carboniferous southward subduction that finally closed the Late Devonian to Early Carboniferous North Tianshan oceanic basin was followed by Permian–Mesozoic polyphase transcurrent faulting.     

New Advances in the Study of the Devonian-Carboniferous Boundary Stratotype in Muhua,Changshun,Guizhou——An Introduction to the Daposhang Devonian-Carboniferous Boundary Section

The Daposhang section at Muhua, Changshun. Guizhou. is an excellent and attractive DevonianCarboniferous boundary section. The transitional beds between the Devonian and Carboniferous of the sectionare continuous and well exposed. belonging to the deep-water basin facies Abundant fossil groups have beendiscovered from this section: conodonts. ammonoids. trilobites. ostracods. vertebrate microfossils and so on.So far as known. it has the most continuous and complete conodont zonation for the Devonian-Carboniferousboundary beds in the world. It is especially worth pointing out that both typical Siponodella pracsulcata andthe transitional forms between S. praesulcata and S. sulcata have been found from the upper pracsulcata Zoneof the Daposhang section. Evidently. we can not only prove the actual existence of the evolutionary lineagefrom S. praesulcata to S. sulcata, but also exactly define the level of the Devonian-Carboniferous boundary. Inthis paper. the development of the Devonian-Carboniferous boundary beds at the Daposhang section is dealtwith and the section is compared with the Muhua section and the Nanbiancun section which are the candidatesfor the Devonian-Carboniferous boundary stratotype. In the authous opinion the Daposhang section is obvi-ously better than the Muhua and the Nanbiancun sections. hence it can be recommended as one of the candi-dates for the international Devonian-Carboniferous boundary stratotype.