Late Ordovician and Early Devonian conodonts from Onoo Tolgoi area of Mongolia

Conodont samples were collected from three localities in the Onoo Tolgoi area,Mongolia, and many conodonts have been found. Conodonts from the Onoo Tolgoi Formation (M288-M294) lack index fossils; its age could be Late Silurian. Samples from the Hutul us hudag Formation (M295-M299) contain Ozarkodina pandora alpha Morph. (P element), clearly indicating that this formation is Early Devonian late Lochkovian in age. Samples collected from so-called Silurian Onoo Tolgoi Formation at other localities(M300-M303) yield many Ordovician conodonts, including Icriodella baotaensis, Icriodella cf.baotaensis, Eoplacognathus jianyeensis, Eoplacognathus protoramosus; Baltoniodus alobatus; and ?Ambalodus triangularis; the age is Late Ordovician,more precisely, early-middle Late Ordovician.     

The First Discovery of the Earliest Devonian Conodont Zonal Fossil from the "Gavuu Member" in Mushgai Area of South Gobi,Mongolia

Conodont Caudicriodus woschimidti woschmidti has been found from a big outcrop (hill) of the Bayan-Kho-shuu Ruins Section which was previously assigned to the Silurian Gavuu Member of the Mandalovoo Formation. This isfirst time to find the lowermost Devonian conodont zonal fossil in Mongolia. The lower part of the Gavuu Member is Silurian. But the strata from where we collected samples M-9～M-12 definitely belong to Lower Devonian (lower Lochko-vian) rather than Lower Silurian. The Mandalovoo Formation should be named Mandalovoo Group, and its three members should be changed into three formations.     

陕西宁强二郎坝志留系的研究

剖面测自陕西省宁强县二郎坝乡景家沟,共鉴定各类化石约160个属种。依据岩性、岩相和化石特征,将该剖面划分为龙马溪组、崔家沟组、王家湾组和宁强组.并对王家湾组、宁强组的划分、对比及时代提出了新的意见。     

陕西西乡地区志留纪地层的研究

本文根据三个地层剖面,对西乡地区的志留纪地层进行了较为深入的研究。将该地区的志留纪地层划分为龙马溪组和崔家沟组,且首次建立起该地区志留纪的生物地层系统——笔石分带。但龙马溪组底部的笔石带则属奥陶纪。还将西乡地区的志留系与国内外有关的几个地区的志留系进行了对比。     

塔里木柯坪地区下志留统碎屑锆石U-Pb年代学特征及其地质意义

柯坪地区物源及演化与塔里木盆地的古地理位置密切相关。通过对下志留统碎屑锆石的形态特征和U-Pb年龄分布特征进行分析,系统研究了柯坪地区下志留统的物源及其演化。结果表明:柯坪地区下志留统锆石均为岩浆锆石,锆石U-Pb年龄反映的是成岩年龄或结晶年龄,可有效指示物源区;下志留统柯坪塔格组的物源区主要为沙雅隆起西部、塔中隆起及塔西南前缘隆起,之后受海侵的影响,塔中隆起被海水淹没,下志留统塔塔埃尔塔格组的物源区演变为沙雅隆起西部、塔西南前缘隆起及塔中隆起的南部于田、康西瓦地区;满加尔凹陷的存在使得柯坪地区与塔中、塔东地区的物源具有很大的差异;900～700Ma的锆石年龄谱表明,塔里木地块与冈瓦纳大陆具有一定的亲缘关系。     

Biostratigraphy of Asmari Formation in Ghare Agha seyed of Farsan region,Chaharmahale Bakhtiari Province,Iran

The Asmari Formation consists of shallow marine sedimentary rocks deposited on ramp setting .Lar-ger benthic foraminifera collected from Asmri Formation are dominated by hyaline and porcelanouse forms , in-cluding Amphistegina, Nummulites, Archaias, Astrotrillina, Miogypsinella, Miogypsinoides, Lepidocyclina, Operculina, Spiroclypeous and Miliolids.The presence of Nummulites cf.vascus in the lower part of the forma-tion allows the age to be determined as Rupelian .The occurrence of Borelis pygmae is an index taxon of the Ru-pelian-Chattian and indicates Early Chattian of SBZ 21-22 in the study section .The first appearance of Mio-gypsinella akadagensis shows Late Chattian ( SBZ 23) and defines the upper boundary of the SBZ 21-22.The new data are the first evidences showing that the shallow marine Asmari Formation is attributed to Oligocene (Rupelian-Chattian) age for this region.     

应用洞穴考古成果建立辽东地区中、上更新统标准剖面

辽东地区第四系不发育。近年,由于旧石器时期遗迹的发掘,积累了较丰富的古动物、古人类资料,使得我们有可能应用这一成果建立辽东地区中、上更新统的标准剖面。辽东地区中更新统称庙后山组(太子河地区)和牛心山组(丹东—营口区);上更新统称山城子组(太子河地区)和金牛山组(丹东—营口区),代表了0.377—0.017Ma期间的堆积。古生态分析表明,庙后山期(牛心山期)为温暖湿润的森林—疏林草原型自然景观;山城子期(金牛山期)为寒冷的干旱草原—半荒漠型自然景观。     

甘肃省文县关家沟组微古植物化石的发现及地质意义

通过对甘肃省文县关家沟组剖面的系统采样,获得大量微古植物化石,鉴定出16个属28个种。依据中国南方及其他地区南华系、震旦系资料,将本区关家沟组的微古植物化石组合特征与峡东、川西北等地区的晚南华世南沱期的微古植物化石组合进行对比,确认关家沟组地层时代为晚南华世南沱期。这一结果对研究关家沟组地层对比、时代划分提供了依据。     

四川广元地区朝天剖面上二叠统吴家坪组凝灰岩成因及其地质意义

四川广元地区朝天剖面上二叠统吴家坪组凝灰岩位于茅口组顶部王坡层黏土岩之上,其成因可能对认识峨眉山大火成岩省火山活动时限具有重要意义。对朝天剖面吴家坪组2个凝灰岩样品进行全岩矿物含量、地球化学特征、锆石U-Pb定年、锆石微量元素和Hf同位素分析,探讨凝灰岩的成因,进而讨论其对峨眉山大火成岩省火山活动时限的启示。结果表明:广元地区朝天剖面上二叠统吴家坪组凝灰岩主要由黏土矿物组成,锆石U-Pb年龄为(260.1±2.8)Ma,并具有较高的Al2O3/TiO2值(分别为37.90和31.49)、明显的Eu负异常(Eu/Eu*值分别为0.13和0.06)及缺失Nb、Ta负异常;凝灰岩样品中,锆石具有较高的εHf(t)值(7.8~11.4)和较低的Th/Nb值(5.4~14.9),与宾川剖面峨眉山火山序列酸性熔结凝灰岩及上寺剖面上二叠统下部凝灰岩基本一致,而明显不同于清音阁王坡层黏土岩锆石εHf(t)值和Th/Nb值。综上所述,四川广元地区朝天剖面上二叠统吴家坪组凝灰岩的形成与峨眉山大火成岩省酸性火山活动有关,且峨眉山大火成岩省的火山活动时限可能一直持续到晚二叠世早期。     

140OΜα前的后生动物实体化石?

本文首次报道了在我国豫西晚前寒武系白草坪组中发现的一种可能的蠕虫状后生动物实体化石:Ruyangia Cylindrica Hu et Meng,1989。化石产于砂岩表面浪成波痕之波谷中,圆筒状,已压扁,中空,可见长度4.5～9.5cm,直径4mm左右,虫体外壁具体环,环背间距1.5～2mm,虫体一端较大,具平行纵向边缘的纵纹,可能为头部;另一端渐尖,可能为尾部。与该实体化石伴生的有大量遗迹化石。已知白草坪组的时代超过1400Ma,因此,该实体化石的发现对研究地球上后生动物起源与早期演化等具重要意义。     

论大巴山地区的临湘组

我国上扬子地区奥陶系宝塔组与五峰组之间的介壳相地层历来存在两个岩性组:一个是临湘组,岩性为绿灰色瘤状灰岩,另一个是涧草沟组,岩性为灰黄色砂质页岩.二者均曾建立Nankinolithus带。1975年以后,涧草沟组一名被广泛引用于大巴山地区,意指宝塔组顶部瘤状泥灰岩以上的黄绿或桔黄色页岩,厚仅数十厘米.本文以五个实测地层剖面为例,从岩性特征和化石内容论证大巴山地区原宝塔组顶部的瘤状泥灰岩实与其上的原涧草沟组页岩为一套独立的岩性地层单元,符合临湘组的概念,故改大巴山地区的涧草沟组为临湘组。并据化石与国内外相当地层进行对比.     

从叶肢介化石讨论田师傅东营坊组的时代

辽东本溪田师傅和新开岭地区出露的一套沉积碎屑岩,范国清(1982年)称为东营坊组,时代隶属晚侏罗世。本文依据 Euestheria ziliujinensis 群将东营坊组时代置于中侏罗早中期,与辽西海房沟组、冀北九龙山组叶肢介动物群主体基本一致。依据 Pagiophyllum cf.maculosum,P.cf.shahoziensis,Brachyphyllumcf.mamillare,Coniopteris sp.等植物化石和区域地层接触关系,东营坊组应置于转山子组、大堡组和三个岭组之上。     

中亚成矿域Erdenet斑岩型铜钼矿床和Oyu Tolgoi斑岩型铜金矿床对比

中亚成矿域位于北侧西伯利亚克拉通、南侧华北—塔里木克拉通及西侧东欧克拉通之间,与环太平洋成矿域和特提斯成矿域并称为全球三大成矿域,发育有一系列大型—超大型斑岩型铜金、斑岩型铜(金、钼)及斑岩型铜钼矿床.对比研究了中亚成矿域两个典型斑岩型矿床——Er-denet斑岩型铜钼矿床与Oyu Tolgoi斑岩型铜金矿床的矿床地质...     

宜阳罗圈组的发育特征和成因探讨

本文根据河南宜阳罗圈组发育特征和分布规律，结合华北地台西南缘罗圈组发育和分布概况，论述了其成因和成因类型，提出了罗圈组时代的归属，认为罗圈组应是大陆高原冰川活动产物。其时代应属早震旦世晚期，大体相当于南沱组。     

鲁中地区早奥陶世早期头足类的发现

广泛分布于鲁西地区的白云岩,本世纪初至五十年代归属于奥陶系济南石灰岩的下部。1961年测制1/20万地质图时改称为冶里组,当时仅在安丘柿子园地区采到腹足类Ophileta,但其时代与对比还是以岩性及其上,下层位为主要依据,将不含燧石的白云岩与河北唐山地区的冶里组对比。陈均远和邹西平将这一部分白云岩称纸坊庄组第一段。笔者和安泰庠、王     

陕西南郑福成奥陶系－志留系界线的笔石

通过对南郑福成奥陶系－志留系界线的笔石组合和笔石体形态等的研究，再次论证了奥陶系与志留系界线以划在Ｇ·ｐｅｒｓｃｕｌｐｔｕｓ带之底为宜，并对界线附近的部分重要和特征笔石进行了描述。     

Anomozamites (Bennettitales) from Middle Jurassic Haifanggou Formation,western Liaoning,China

The Middle Jurassic Hangfanggou Formation is well exposed in Shangsanjiao and Xiasanjiao villages area,Baimashi town of Huludao,western Liaoning,China.Recently,abundant fossil plants were collected from the Hangfanggou Formation.One new species,Anomozamites sanjiaocunensis sp.nov.(Bennettitales),is described in this study.This is the first report of the genus Anomozamites from the Haifanggou Formation based upon the leaf morphology and epidermal structures.The discovery of the new species extends significantly the stratigraphic and geographic distribution of Anomozamites in the Middle Jurassic.It also shows that Anomozamites was a common member of Bennettitales once lived in the Middle Jurassic warm temperate region.The new species also improves the knowledge on understanding the leaf morphology,epidermal features and the diversity of Anomozamites during the Middle Jurassic.The epidermal characters of the new species and its associated plants reveal that the plants grew in a warm and moderately humid environment in the warm temperate zone.The presence of some deciduous plants,such as ginkgoaleans,czekanowskialeans and conifers,indicate the climate with seasonal fluctuations in temperature.     

Stratigraphy of southeastern flanks of Raichikhinsk brown coal field (Zeya-Bureya sedimentary basin)

The results of the palynologic and paleobotanic analyses have allowed determining the Paleocene (including Danian) and Eocene deposits in the series of coal-bearing sediments of southeastern flanks of the Raichikhinsk brown coal field. Their age was corroborated by the palynologic and paleobotanic data. The detailed biostartigraphic data were obtained in the area"Pioneer" for the first time. The coal-bearing strata were correlated with those from the sections of the Arkhara-Boguchan brown coal field and the stratotype of the Tsagajan Formation of the Bureya Belogor'ye.     

Stratigraphy of southeastern flanks of Raichikhinsk brown coal field （Zeya-Bureya sedimentary basin）

The results of the palynologic and paleobotanic analyses have allowed determining the Paleocene (including Danian) and Eocene deposits in the series of coal-bearing sediments of southeastern flanks of the Raichikhinsk brown coal field. Their age was corroborated by the palynologic and paleobotanic data. The detailed biostartigraphic data were obtained in the area““ Pioneer““ for the first time. The coal-bearing strata were correlated with those from the sections of the Arkhara-Boguchan brown coal field and the stratotype of the Tsagajan Formation of the Bureya Belogor‘ye.