对黑龙江东部龙爪沟群和鸡西群时代的不同认识

本文论述了黑龙江东部的含煤地层龙爪沟群和鸡西群的时代。这两群的时代长期以来被归属或主要归属于侏罗纪。但龙爪沟群上云山组和鸡西群城子河组下部产中Barrem Jan—早Albian期的双壳类Aucellina化石,龙爪沟群七虎林组产早白垩世双壳类和菊石化石。因此,这两群的时代主要甚至全部为早白垩世。     

中国东北、韩国东南和日本西南部早白垩世非海相与海相地层对比,非海相软体动物的生物年代学和古地理意义

根据非海相与海相,特别是共同的海相和非海相软体动物化石的对比,并结合放射性同位素测年,中国东北黑龙江东部和辽宁西部,韩国东南部庆尚盆地,日本西南部内带岐阜县北部牧户/庄川地区和外带四国德岛和物部地区早白垩世地层得到了对比,产自这些地层的非海相软体动物的时代也因此受到了约束。著名的中国东北含煤地层龙爪沟和鸡西群,盛产热河生物群/动物群的热河群的时代均为欧特里沃期/巴列姆期阿普特期,它们的上覆地层桦山群和孙家湾组为阿尔必期。韩国西南部新洞群和除金洞组以外的河阳群为阿普特期阿尔必期,不整合于新洞群之下的卯谷组主要为欧特里沃期。日本西南部内带的牧户/庄川地区的手取群和外带德岛和物部地区的物部川群均为欧特里沃期阿尔必期。Cuniopsis kihongi,Nakamuranaia leei,Koreanaia cheongi和Trigonioides(Wakinoa)tetoriensis的时代为欧特里沃期早巴列姆期。Viviparus onogoensis,Unio ogamigoensis,Myrene(Mesocorbicular)tetoriensis及Tetoria(Tetoria)yokoyami为欧特里沃期阿普特期。Arguniella cf.quadrata,A.cf.ventricosa,Sphaerium(Sphaerium)anderssoni,Probaicalia vitimensis和Pr.gerassimovi为欧特里沃期/巴列姆期阿普特期。Nakamuranaia chingshanensis,Plicatounio(Plicatounio)multiplicatus,Sphaerium(Sphaerium)coreanicum和Micromelania?katoensis为阿普特期阿尔必期。Nippononaia sinensis,Nip.tetoriensis,Nip.ryosekiana和Trigo-nioides(Wakinoa)wakinoensis是阿普特期的标志。Trigonioides(Trigonioides)quadratus,T.(T.)heilongjiangensis,Plicatounio(Plicatounio)naktongensis,Unio longus与Sphaerium(Sphaerium)chintaoense为晚阿普特期阿尔必期或阿尔必期的标志化石。我国东北、韩国东南和日本西南部非海相,特别是淡水软体动物接近的相似性表明这三地区在早白垩世时相连,并处于同一水系。但是,在欧特里沃期阿尔必期期间,这一陆块的东部,即频临古太平洋的日本西南部的外带因地势低而多被海水覆盖,在牧户/庄川和黑龙江东部存有遭受海侵的浅而窄的海湾,凡兰吟期,特别是欧特里沃期/巴列姆期之前,中国东北韩国东南部日本西南部陆块为受造山运动引起的隆起和沉降活动影响的高低不平的高原,经受了广泛而长期的剥蚀。多数含有包括熔岩和凝灰岩在内的火山岩,并与北东北北东方向的断裂带近于平行分布的非海相白垩纪盆地直至欧特里沃期/早巴列期(有些地区可能稍早(凡兰吟期))(134～126Ma),即华北克拉通破坏的高峰期(130～120Ma)才形成。这一现象表明,这些盆地受断裂,特别是伴随有强烈火山喷发和时而局部海侵的沿着古太平洋西北缘和郯庐断裂带的构造运动的控制。     

吉林省九台县羊草沟煤矿孢粉组合及时代

本文介绍了羊草沟煤矿区的地层概况,对营城组和泉头组孢粉组合分子的基本特点,进行了详细地剖析,并与国内外已有研究成果作了对比。认为其时代均属于早白垩世,其中前者为巴列姆-阿普梯期,后者为阿尔必期。     

城子河组的新材料及其地层意义

黑龙江省密山县金沙农场北部鹿山地区被钻孔揭示的城子河组剖面产有海相一半成水相双壳类、沟鞭藻，孢子花粉及植物化石，这些新材料进一步证明城子河组的时代应属早白垩世早中期，从而为侏罗～白垩系界线划分及鸡西群与龙爪沟群对比提供了新的生物地层依据。     

云南江城勐野井组钾盐成矿时代及其古环境研究

研究云南江城勐野井组的成钾时代, 对于分析兰坪—思茅盆地与老挝沙空那空、呵叻盆地含盐系地层对应关系, 以及在云南开展钾盐找矿工作具有重要意义, 但勐野井组的地层学年代至今仍存在较大分歧。本文通过对江城宝藏乡泰裕矿区含盐系地层的孢粉分析, 得到孢粉组合: Psophophaera-Exesipollenites- Classopollis, 且发现单沟类Monocolpopollenites和三沟类Tricopite等被子植物花粉, 此被子植物花粉时代分别为晚巴列姆期—阿普第期和早、中阿尔必期。因此, 笔者将江城勐野井组钾盐成矿时代确定为阿普第期—阿尔必期; 同时, 孢粉反映矿区成盐期气候呈炎热干旱的热带-亚热带特征。     

论甘肃玉门红柳峡下沟组的时代北大核心CSCD

甘肃玉门红柳峡地区下沟组双壳类化石丰富,计有7属18种,包括Musculiopsisfuxinensis,M.yixianensis, M. subrotundus, Sphaerium anderssoni, S. coreanicum, S. selenginensis, S. chientaoense, S. ellipticoides,Gansuellaxinminpuensis,G.angulate,Nakamuranaiachingshanensis,N.subrotunda,N.aff.chingshanensis,Arguniellalingyuanensis,A.yanshanensis,A.liaoxiensis,Inversidenswuerheensis和Unioyanbianensis。据此建立Nakamuranaia subrotunda-Musculiopsis fuxinensis组合。该组合可与外贝加尔东部、浙江西部、辽宁西部、黑龙江东部、韩国东南部、日本西南部的早白垩世双壳类动物群对比,时代为Aptian期—Albian期。下沟组上段发育的火山颈相辉绿岩锆石U-Pb同位素测年结果为109±1.6Ma,形成时代也为早白垩世。双壳类化石和火山颈锆石年龄都表明下沟组时代为早白垩世Aptian中期—Albian早期,并且早于109 Ma。     

福建晚中生代兜岭群时代与区域地层对比

中国东部晚中生代广布的陆相火山盆地沉积,由于海相生物化石的匮乏造成与层型地区对比的困难,长期以来该地层时代仅笼统被认为属于晚侏罗世-早白垩世。通过岩石组合、构造层和沉积构造环境的综合对比,确立闽西地区的兜岭群与闽东地区南园群、浙西建德群可以对比,构造不整合面代表区域上由挤压向拉张构造背景转化的相对等时界面。兜岭群的植物群Cupressinocladus --Brachyphyllum 组合可能与北方的Ruffordia --Onychiopsis 植物组合大体相当,叶肢介、介形类、腹足类和双壳类等化石与浙江早白垩世建德生物群、北方的热河生物群均可以对比,时代应为早白垩世欧特里夫期-阿普特期。     

风火山群的孢粉组合及时代意义

本文讨论了青海省唐古拉山地区风火山群的孢粉组合及时代,简述了地层层序及岩性特征。文中通过实际资料的对比,说明了风火山群孢粉组合的特点,同时指出风火山群既不属于晚白垩世也不是第三纪,而应归于早白垩世,置于早白垩世欧特里夫—巴列姆期更为合适。     

早白垩世热河生物群北部分布区的脊椎动物群和地层

一般认为中国北方的燕辽地区(冀北和辽西)是热河生物群起源和演化的中心, 因此中国的大兴安岭北部和俄罗斯外贝加尔地区可视为热河生物群化石分布的北部区。大兴安岭北部一个新发现的化石点产热河生物群鱼群重要分子燕鲟属和中华弓鳍鱼属, 但这一地区还未发现四足动物化石。外贝加尔地区的Krasnyi Yar和Mogoito两个化石点产较丰富的早白垩世脊椎动物化石, 层位和时代分别为Khilok组(阿普特期), Murtoi组(晚巴列姆-中阿普特期)。与热河生物群其他分布区相比, 北部区和燕辽地区的脊椎动物群组成和古环境背景更为相似。     

海拉尔盆地海参1井伊敏组孢粉组合的地层意义

海参1井伊敏组孢粉化石异常丰富,自下而上可以划分出3个孢粉组合:Impardecispora-Cyathidites-Clavatipollenites组合,Stereisporites-Deltoidospora-Asteropollis组合,Appendicisporites-Asteropollis-Tricolpites组合,分别分布于伊敏组一段、二段和三段,组合特征明显,是海拉尔盆地乌尔逊凹陷划分伊敏组与大磨拐河组的重要生物依据之一,更是伊敏组内三段划分和井间对比的生物依据之一。3个孢粉组合中见有属种繁多的海金沙科孢子及其他繁盛于早白垩世中晚期的孢子花粉,结合在绝大多数样品中发现的早期被子植物花粉的情况分析,推测含这3个孢粉组合的伊敏组地质时代为早白垩世巴列姆期—早阿尔必期(Barremian—Early Albian)。     

Studies on the Early Cretaceous Longzhaogou and Jixi Groups of eastern Heilongjiang,northeast China,and their bearing on the age of supposedly Jurassic strata in eastern Asia

The coal-bearing Longzhaogou and Jixi Groups in eastern Heilongjiang, northeast China, consist of alternating marine and non-marine deposits containing abundant marine animal and plant fossils. The Jixi Group also yields members of the Johel Fauna that is widely distributed in northern and eastern China. The two groups have been considered as Jurassic or mainly Jurassic in age for a long time. However, recent studies documented that the ammonites, bivalves, dinoflagellates, angiosperms and sporopollens are all of Early Cretaceous rather than Jurassic age. It has been demonstrated that: (1) the Longzhaogou and Jixi Groups and their equivalents, the Johel Group of China and the Transbaikalian Group of Russia, are of Early Cretaceous age, (2) the Barremian-Albian was also a very important period of coal accumulation in northeastern China and perhaps in all of eastern Asia, (3) there existed a large shallow embayment connecting with the Palaeo-Pacific in eastern Heilongjiang, and it was the climate of the embayment that controlled the origin and development of the animal and plant communities of northeastern China during the Early Cretaceous. Correlation between formations in the Jixi and Longzhaogou Groups has also been revised in this paper.     

The Upper Jurassic–Lower Cretaceous of eastern Heilongjiang, northeast China: stratigraphy and regional basin history

In eastern Heilongjiang, the Upper Jurassic is marine and restricted to the Suibin and Dong’an areas, where it is characterized faunally by Callovian–Volgian (Tithonian) bivalves and florally by dinoflagellates. The Lower Cretaceous is widely distributed in eastern Heilongjiang, and characterized faunally by Berriasian–Valanginian bivalves, Barremian–Albian ammonites and Aucellina, and florally by dinoflagellates. To the west, the marine facies grade into non-marine beds. Thus, in the east, for example in the Dong’an and Dajiashan areas, near the northwestern Palaeo-Pacific, the Lower Cretaceous is marine; westward, in the Yunshan, Longzhaogou, Peide, and Zhushan areas, marine and non-marine deposits alternate, whereas further west still, e.g. in the Jixi Basin, non-marine facies are intercalated with marine beds. This regional distribution is indicative of a large, shallow embayment opening eastwards to the Palaeo-Pacific; during the Early Cretaceous successive transgressive-regressive events influenced the climate and biota of eastern Heilongjiang and northeastern China. Many of the Lower Cretaceous sections contain abundant coals, demonstrating that in this region the Early Cretaceous was an important coal-forming period. Some non-marine bivalve species are common to the Lower Cretaceous Jixi Group of eastern Heilongjiang, the Jehol Group of western Liaoning and the Transbaikalian Group of Siberia, suggesting that these groups are of comparable Early Cretaceous age.     

A Different Opinion on the Geological Age of the Longzhaogou and Jixi Groups of Eastern Heilongjiang,China1

Abstract The age of the Longzhaogou and Jixi Groups of coal measures in eastern Heilongjiang were previously considered to be Jurassic or mainly Jurassic. But there occur Middle Barremian- Early Albian Aucellina ( bivalvia) fossils in the Upper Yunshan Formation of the Longzhaogou Group and the Lower Chengzihe Formation of the Jixi Group, and the Qihulin Formation of the Longzhaogou Group yields Early Cretaceous bivalve and ammonite fossils. Consequently, the geological ages of the two groups are mainly, or even all, Early Cretaceous.     

黑龙江鸡西含煤盆地早白垩世生物地层研究新进展

近年来鸡西含煤盆地早白垩世海相沟鞭藻及早期被子植物化石的不断发现,为确认了河组及其下伏滴组、上覆穆棱组的时代属早白垩世提供了重要的依据。通过海相及海陆交互相生物地层研究,恢复晚中生代黑龙江省东部古地理格局,为扩大找煤远景等提供了新的基础资料。     

黑龙江省东部中侏罗世至早白垩世沟鞭藻组合序列

对近二十年来黑龙江省东部海相侏罗纪—白垩纪沟鞭藻地层资料进行了综合研究 ,首次为该地区建立起侏罗纪—白垩纪沟鞭藻地层序列 ,主要包含 7个组合带 (含 3个高峰带 ) ,其中绥滨地区 Callovian— Valanginian期有 4个带 ;鸡西盆地早白垩世也有 4个带 (其中包括与绥滨地区早白垩世早期同时异相的一个 )。它们自下而上为 :1)绥滨组的 Pareodinia ceratophora- N annoceratopsispellucida组合带 ;　 2 )东荣组下部的 Gonyaulacysta jurassica组合带 (高峰带 ) ;　 3)东荣组上部的 Amphorula delicata组合带 ;　 4 )东荣组最上部的海相 Oligosphaeridium pul-cherrimum组合带 (高峰带 )或鸡西盆地滴道组的微咸水—半咸水的 Vesperopsis didaoensis- L agenorhytis granoru-gosa组合带 ,两者为同时异相关系 ;　 5 )城子河组下部海相层的 Odontochitina operculata- Muderongia tetracantha组合带 (该带可进一步划分出 2个亚组合带 ) ;　 6 )城子河组上部海相层的 Canningia reticulata组合带 ;　 7)穆棱组下段的 Cribroperidinium ?parorthoceras组合带 (高峰带 )。     

黑龙江省东部白垩纪含煤地层简介

黑龙江省东部早白垩世含煤地层的分布特点是西部含煤层多、厚度大，向东含煤层数量减少、厚度减薄，大型矿区也主要分布在西部。该区的含煤盆地多为向斜盆地，含煤情况比较好的大型矿井都在向斜的北翼，而向斜南翼基本没有形成较好的煤层。在含煤盆地内，距断陷中心较远且沉降幅度不大的地区通常具有较好的聚煤条件，而在沉降幅度较大、沉积地层较厚的沉降中心地带反而没有形成良好的可采煤层。含煤地层的分布特点反映了本区成煤期构造、古地理和古气候的演化历史。根据生物地层学证据，可将鸡西群和龙爪沟群进行对比，它们的时代无疑应为早白垩世。     

中国东北中生代地层划分对比之新见

在总结近二十年来有关我国东北地区中生代地层研究诸多新发现与新进展的基础上 ,以生物化石为主要依据 ,以 "海相检验法”及国际性生物地层对比为标准 ,结合同位素年代地层学新资料 ,对东北地区中生代地层的划分及对比 ,提出了新的方案。文中还讨论了三叠系 -侏罗系界线、侏罗系 -白垩系界线及下白垩统 -上白垩统界线的划分以及辽西义县组的时代。同时 ,还首次报道了笔者等对黑龙江东部龙爪沟群研究的最新进展 ,并提出了对龙爪沟群时代及与鸡西群对比的新认识。     

黑龙江省东部鸡西群穆棱组年代地层划分

利用最新的古生物、磁性地层年代资料、高分辨率层序延续时间推算及与全球海平面升降曲线对比等方法,对鸡西群穆棱组进行了精细的年代地层划分,确定了穆棱组形成时代为早白垩世巴雷姆早期-阿尔布早期,绝对年代为116~107 Ma,其中穆棱组下部主要含煤段形成时间为115~111 Ma.这一研究成果为黑龙江省东部早白垩世高精度地层划分对比及成煤期次的确定提供了精确的年代依据.     

Early Cretaceous spinicaudatans (“conchostracans”) from lacustrine strata of the Sidi Aïch Formation in the northern Chotts range,southern Tunisia: Taxonomy,biostratigraphy and stratigraphic implication

The fossil clam shrimp genus Cratostracus was first described from the Turonian–Coniacian (Upper Cretaceous) Qingshankou Formation in the Jilin and Heilongjiang provinces of China, and it has been found to range down into the Aptian Guantou Formation in Zhejiang Province of southeastern China. Recently, species tentatively attributable to it (Cratostracus? cheni) has been recorded in the well-known Jehol Biota bearing Barremian–lower Aptian (Lower Cretaceous) Yixian Formation in western Liaoning Province of northeastern China. The species described in this paper as Cratostracus? tunisiaensis sp. nov. was recovered from the Sidi Aïch Formation in the Chotts area of southern Tunisia. Although only tentatively attributed to Cratostracus, its occurrence is consistent with a Barremian (Early Cretaceous) age for the formation. This first direct dating of the Sidi Aïch Formation gives a valuable insight for the stratigraphy of the region and will make it possible to more precisely correlate the different outcrops of the Sidi Aïch Formation. Moreover, the new fossil discovery allows a reconstruction of the paralic ecosystem that characterized the study area during the Barremian.