A new permian bivalve zonal scale of Northeastern Asia. Article 2: Correlation problems

The problems of the intra- and regional correlation of Permian sections of Northeastern Asia are considered based on a new zonal biostratigraphic bivalve scale. The interregional correlation was performed for the Permian deposits in the eastern part of the Boreal Superrealm and some adjacent regions. The possibilities and problems of bivalve-based correlation of Permian sediments in extraboreal regions are discussed.     

贵州紫云晒瓦晚二叠世深水相地层

通过对晒瓦晚二叠世岩石地层和生物地层的初步研究 ,认为晒瓦晚二叠世地层属于深水相沉积 ,可划分成4段 ;并根据双壳类、腕足类延限和发育特征 ,分别建立了一个双壳类化石带 (Claraia primitiva- H unanopecten exi-lis组合带 )和二个腕足类化石带 (N eochonetes substrophomenoides- Orthothetina ruber组合带 ,Acosarina dorsisulca-ta- Crurithyris speciosa组合带 ) ;在对牙形石、双壳类和腕足类等典型化石的综合研究基础上 ,首次划分出吴家坪阶和长兴阶 ,改变了以往本区晚二叠世年代地层未细分的状况 ,提高了划分对比精度。     

哈密晚二叠世双壳类化石发现及地质意义

哈密路白山地区黄岗一带原划为大热泉子组中,发现时代属晚二叠世的Palaeanodonta castor,P.fischeri,Palaeomutela urumqiensis,Pneglecta P.verneuili,Oligodon keerjiensis,等淡水双壳类化石,其动物群面貌与乌鲁木齐和吐鲁番上二叠统梧...     

滇西南澜沧县老厂浅水相“老厂组”时代之订正

对澜沧县老厂水库东侧公路剖面开展系统的生物地层学研究,证实西盟至竹塘公路１３～１４ｋｍ 区段属Ｅｏｓｔａｆｆｅｌｌａ 带,１２．５～１３ｋｍ 区段属Ｐｓｅｕｄｏｓｔａｆｆｅｌｌａ 带。所谓的浅水相“老厂组”和冬瓜林火山岩的时代应修正为早石炭世德坞阶至晚石炭世滑石板阶,宜归入平掌组的范畴。确认老厂矿区存在有两套不同时代、不同构造背景的火山岩     

The Carboniferous and Permian sequences in north and south of the Longmucuo-Shuanghu suture zone in Tibet

The location of the Palaeo-tethys suture in Tibet has been in great dispute for past two decades. The Longmucuo-Shuanghu suture has long been considered as the Palaeo-tethys in Tibet. Restudy of the Carboniferous and Permian sequences in the north and south of this suture reveal that: (1) the Carboniferous and Permian se-quence of the North Qiangtang Block is characterized by containing compound corals and intact fusulinids zones from Moscovian Fusulinella, Fusulina to Changhsingian Palaeofusulina zones; (2) the Early Permian of the South Qiangtang Block is dominated by diamictites and the Middle Permian carbonates found there may deposit on the oceanic seamount.     

Significance of Caucasian Sections for Working out Carbon-Isotope Standard for Upper Permian and Lower Triassic （Induan） and Their Correlation with the Permian of North-Eastern Russia

Data obtained on conodont distribution in the Permian-Triassic Sovetashen Section of Transcaucasia provide further limitations on the age of the carbon-isotopic anomalies discovered by Baud et al. (1989). The significance of Caucasian sections for working out the carbon-isotope standard for the Upper Permian and Lower Triassic (Induan) is shown. Original data on carbon-isotope composition of bivalve and brachiopod shells from Permian sediments of North-Eastern Russia (Omolon and Okhotsk areas) have been obtained, which may be used for their correlation.     

滇西澜沧老厂晚二叠世双壳动物群的发现及其生物区系特征

本文描述了采自云南澜沧老厂的双壳类,共计13属、15种和未定种(其中1新属、4新种)。该动物群地质时代为晚二叠世,其组成既有鲜明的地方特色,又与扬子地区有明显联系,属扬子生物区系,并具亚热带生物特征。     

贵州紫云四大寨早三叠世地层初步研究

贵州紫云四大寨剖面下三叠统发育较齐全,化石较丰富。在此剖面上发现了大量牙形石、双壳类、菊石等生物化石,其中牙形石在该剖面上为首次发现,并识别出了早三叠世Neospathodusdieneri带、Neospathoduscrista-galli带、Neospathoduswaageni带和Neospathodushomeri-Neospathodustriangularis带的重要牙形石分子或带化石,可与国际同期地层中相应的牙形石化石带进行较好的对比;同时还发现了Claraiagriesbachi-C.concentrica组合和Claraiastachei-Claraiaaurita组合带的双壳类代表性分子。通过对这些化石综合分析,大致拟定了本剖面下三叠统格里斯巴赫亚阶(Griesbachian)、亭纳尔亚阶(Dienerian)、斯密斯亚阶(Smithian)和斯派斯亚阶(Spathian)的年代地层单位界线。     

江苏南部地区煤层气资源

根据江苏南部地区二叠系龙潭组煤系的分布和规模、煤矿瓦斯涌出特征、煤的产气能力、煤层的储集条件等煤层气地质条件综合研究工作，认为该区煤层气资源存在一定的勘探开发前景，对各典型含煤区块煤层气综合评价出有远景区（A类）、较有远景区（B类）和远景差区（C类）。     

大同煤田构造特征及太原组赋煤边界

为了总结大同煤田构造特征及二叠系太原组赋煤边界形成条件,结合野外露头、钻孔岩性、三维地震等资料,分析了大同煤田构造区带划分、地层结构样式、构造演化及应力场特征,明确了二叠系赋煤边界成因机制。研究表明:晚古生代以来,大同煤田主要经历了印支、燕山和喜山期3期构造运动,其中燕山期构造最为复杂,具有幕式、挤压伸展交替演化特征,控制了煤田现今的构造格局;煤田由东部逆冲断裂构造带,中部向斜-单斜构造带和西部隆起构造带组成,煤田内部断裂多为NW-NWW和NE-NEE向,前者形成时期早,规模普遍较大;不同构造期应力作用控制着二叠系煤层的赋存特征,印支早期NS向挤压作用,控制煤田东北部边界,燕山期控制煤田东缘、西缘和西南缘边界。      

陕西岐山产Eumorphotis的“石千峰组”地层问题

<正> “石千峰群”的问题,是涉及华北及其相邻广大地区陆相二—三叠系划分、对比及界线的重大地层课题,自下而上分为石千峰组(孙家沟组)、刘家沟组、和尚沟组。并确认石千峰组含有晚二叠世的Lueckisporites-Protohaploxypinus 孢粉组合;Abiella sp., Microdontella sp.等瓣鳃类;Sinolimnadiopsis yaoxianensis, Huanghestheria longellipsa等叶肢介;Shihtienfenia permica, Shansisaurus xuecunensis, Tapinocephalidae等脊椎动物化石。刘家沟组含早三叠     

二叠纪-三叠纪之交的古海洋水化学条件变化证据--以贵州织金剖面为例

基于贵州织金剖面的二叠系-三叠系界线附近的岩石薄片鉴定及古生物化石识别,划分出了2种碳酸盐岩沉积相、2种亚相和5种微相;有机质碳同位素组成测试结果表明晚二叠世时期有机质的δ13C_org值（-27.7‰）向早三叠世时期的δ13C_org值（-28.3‰）逐渐偏负,反映了有机质类型由高等植物向低等微生物变化的过程;全岩的δ13C_rock值由晚二叠世（-24.2‰）向早三叠世（-20.9‰）变大,反映了二叠纪末期生物大灭绝事件造成了海洋生物的消失,进而引起12C在海洋中强烈富集;Fe-_HR/Fe-_T、Fe_py/Fe-_HR以及微量元素V/（V+Ni）与V/（V+Cr）比值大小,反映了二叠纪末期该区域的海水为氧化环境或弱还原环境,而三叠纪初期海水处于还原与铁化环境,在盆地内部没有发生硫化作用;V/Ni的值从晚二叠世的0.97~1.97向早三叠世的1.67~7.33明显变大,表明水体逐渐加深的过程,该结论与沉积微相变化相符;在生物演化上,从二叠纪末期的有孔虫-藻屑-三叶虫生物组合演变到三叠纪初期小型介壳-微生物组合,反映了该时期中国南方统一的两幕式生物灭绝与演化样式。     

Uppermost Permian Radiolarian Biostratigraphy of Southern Guizhou,Southwest China

With abundant deep-water upper Permian sediments,Guizhou is an ideal place for the re-search of radiolarian biostratigraphy of Upper Permian.The sections of Sidazhai and Lekang in southern Guizhou Province are studied.Lithology and biostratigraphy of the siliceous rock sequence of uppermost Permian in the two sections are introduced.Radiolarian assemblage zones,Neoalbaillella optima assem-blage zone and Klaengspongus spinosus assemblage zone in ascending order are established for the top-most Permian of southern Guizhou.The Klaengspongus spinosus zone has been the topmost radiolarian assemblage zone of Permian,which is also correlated with former ones in a considerable depth.     

贵州威宁金钟二叠系-三叠系界线剖面生物地层及其对比

二叠纪—三叠纪之交发生了显生宙最大的生物灭绝事件,同时发生了复杂的环境变化.由于陆相二叠系-三叠系界线附近生物化石记录没有海相记录完整,同时也缺乏其他可靠的年代地层标志,所以如何标定陆相剖面的二叠纪—三叠纪界线一直是研究热点和难点.贵州威宁金钟地区二叠纪—三叠纪之交位于康滇古陆的东侧,毗邻海陆过渡相区,可以与同期的浅海碎屑岩相、海陆过渡相、陆相剖面进行由海到陆“追索式”的生物地层对比,是我国研究海、陆相二叠系-三叠系界线及对比的关键研究区之一.研究区的金钟二叠系-三叠系界线剖面中化石丰富,共发现双壳类化石4属6种,叶肢介2属4种,植物化石9属及腕足类化石1属,为海、陆相地层对比提供了桥梁.依据叶肢介Euestheria gutta-Palaeolimnadia xuanweiensis组合、植物Annalepis-Peltaspermum组合以及双壳类Pteria ussurica variabilis-Neoschizodus orbicularis组合的生物化石时代归属讨论,识别出金钟剖面的二叠系-三叠系界线应该在卡以头组下部.通过与邻区不同相剖面的对比,提出双壳类Pteria ussurica variabilis-Neoschizodus orbicularis组合以及陆相的叶肢介Euestheria gutta-Palaeolimnadia xuanweiensis组合可以作为三叠纪最早期的识别和对比标志.      

Permian biospheric events in Northeast Asia

An analysis of the dynamics of diversity of bivalve species in Northeast Asia in the Permian period allowed us to reveal a number of events when it significantly increased or decreased. Four major mass extinction events were established for bivalves: at the end of the Early Permian, in the Early Capitanian age, at the the Capitanian-Wuchiapingian boundary and at the end of the Late Permian. Along with extinction events, five events of taxonomic radiation/innovation were distinguished: Early Asselian, Middle Kungurian, Early Roadian, Late Wordian, and Early Changhsingian. Revealing of these biotic events has been confirmed by the dynamics of biodiversity in other major groups of Permian fauna (foraminifers, brachiopods, ammonoids). Moreover, they are evidenced in different basins by changes in the character of sedimentation, isotope parameters, eustatic variations and other environmental factors. Most of the events can be traced far beyond Northeast Asia. Their manifestation is associated with general reasons (variations in endogenous regime of the Earth and associated stress effects on the biota). According to this, results of studying these events can be used for global correlations.     

福建晚古生代聚煤构造特征及其演化

福建省晚古生代聚煤前的区域构造格架为三个地体：闽西北地体、闽西南地体及闽东地体。聚煤期构造特征(早古生代晚期)：加旦东运动沿政和——大埔深大断裂产生了海沟岛弧系俯冲；同时，沿温州——德化深大断裂产生海沟山弧俯冲，海沟岛弧系在晚古生代形成了福建二叠系含煤地层的中、西部条带，海沟山弧系形成了福建二叠系含煤地层的东部条带。聚煤后的构造特征(中生代)，由于印支运动产生新古太平洋板块，并在这时产生了二叠系含煤地层滑脱断层的雏形；燕山运动早期形成了二叠系含煤地层的盖层逆冲推覆构造，燕山运动晚期形成了二叠系含煤地层的基底逆冲推覆构造。     

THE PERMIAN SYSTEM OF THE NUJIANG—LANCANGJIANG—JINSHAJIANG AREA, SOUTHWESTERN CHINA

THE PERMIAN SYSTEM OF THE NUJIANG—LANCANGJIANG—JINSHAJIANG AREA, SOUTHWESTERN CHINA     

The geological development of the southern part of the New England Fold Belt

Two major divisions of the New England Fold Belt, Zone A and Zone B, are separated by the Peel Fault. Deposition in these two zones was probably contemporaneous (Lower Palaeozoic ‐ Lower Permian). Terminal orogenesis in both zones was also contemporaneous (Middle Permian) but whereas in Zone A deformation was only moderate, metamorphism was of burial type, and granitic emplacement was uncommon, in Zone B many rocks were severely deformed and regionally metamorphosed, and both syn‐tectonic and post‐tectonic granites are widespread.

Pre‐orogenic palaeogeography is envisaged in terms of an evolving volcanic chain ‐ fore‐chain basin ‐ trench system, with an outer non‐volcanic arc developed in the Carboniferous. Cessation of movement on a subduction zone dipping westward beneath the volcanic chain is believed to have caused the Middle Permian deformation, but neither metamorphism nor the granitic rocks are directly related to subduction.     

贵州水城仲河剖面二叠纪-三叠纪之交底栖群落的物种多样性与功能多样性转变

为了定量化恢复晚二叠世末期生物大灭绝对底栖群落的物种多样性和功能多样性的影响,对浅海碎屑岩台地相区的贵州水城仲河剖面开展宏体化石采集和分析,识别和划分古群落,选择优势度、香农指数、均匀度等代表物种多样性指数,生态功能群数量和功能均匀度代表功能多样性指数. 共采集1 340枚化石标本,经鉴定得到30属33种,其中双壳类可归纳为两个生物带:晚二叠世长兴期的Hunanopecten exilis顶峰带和早三叠世Griesbachian早期的Pteria ussurica variabilis顶峰带. 根据化石属种的地层分布、保存状况,结合聚类分析方法识别出3个古群落:Astartella obliqua-Tethyochonetes quadrata群落、Pteria ussurica variabilis-Claraia wangi群落和Pteria ussurica variabilis-Unionites canalensis群落. 自晚二叠世长兴期末期至早三叠世Griesbachian早期,古群落的优势度上升、香农指数降低、均匀度下降,功能群丰富度降低,功能均匀度上升,这指示晚二叠世末生物大灭绝对浅海碎屑岩相区的底栖群落的组成和功能均有显著的破坏. 此外,结合华南浅海和深海相区的古群落数据,发现底栖群落的物种多样性指数和功能多样性指数在晚二叠世末生物大灭绝中均遭受损失,但是浅海底栖群落受影响较高.      

内蒙古阿拉善地区恩格尔乌苏缝合带二叠纪放射虫及其地质意义

报道了采自恩格尔乌苏缝合带的蛇绿混杂岩硅质外来岩块中的二叠纪阿尔拜虫目放射虫化石,包括3属7种,可以划分为2个放射虫化石组合,能够与日本、美国的放射虫化石带进行对比,其地质时代分别为早二叠世和中二叠世晚期—晚二叠世早期。恩格尔乌苏缝合带位于华北板块和塔里木板块之间,这些放射虫化石的发现为研究恩格尔乌苏缝合带的构造演化提供了新的证据。鉴于其中最新的放射虫组合的地质时代为中二叠世晚期—晚二叠世早期,认为华北板块与塔里木板块之间自中二叠世晚期—晚二叠世早期曾经存在古海洋,即华北板块和塔里木板块的拼合时间是晚二叠世晚期。