下扬子区下石炭统底部陈家边组简介

下扬子区下石炭统发育是否完整,长期存在疑问。以往都把下石炭统金陵组视为石炭系最底部一个地层单位,根据珊瑚和腕足类,与贵州汤粑沟组、湖南刘家塘组对比,认为缺失早石炭世早期的沉积。1983年笔者在江苏江宁陈家边、安徽巢湖、宣城、浙北长兴等地测制剖面,系统采集样品,经阎永奎孢子分析鉴定,在江宁陈家边和长兴牛头山等地首次于上泥盆统五通组擂鼓段顶部发现丰富的早石炭世早期的孢子化石组合和疑     

下扬子区下石炭统

本文系统记述下扬子区下石炭统发育情况。着重对本区早石炭世早期是否存在沉积等问题提出新的依据和看法。下扬于区下石炭统发育是否完整,长期存在疑问,根据孢子化石和粒度分析资料,表明区内早石炭世早期的沉积确实存在,并创建了陈家边组,代表这一时期一种碎屑岩沉积类型。下石炭统上部老虎洞组的时代也存在争议,笔者根据白云岩化学组分的多元统计分析结果,提出二分观点,并重新厘定老虎洞组的含义。     

关于苏、皖南部黄龙组下部白云岩时代归属问题

苏、皖南部中、下石炭统之间普遍发育一套白云岩地层,过去通称为“老虎洞白云岩”。 自夏邦栋(1959)创建“老虎洞白云岩”以来,对它的时代归属一直存在分歧。杨敬之等(1962)把它与广西大埔白云岩相比,将它归入中石炭世早期;陈敏娟等(1964 1972,1980)、肖立功(1982)根据南京龙潭、汤山、孔山等地所获得的珊瑚化石资料,将它归入早石炭世晚期。江苏区调队(1972)、安徽区调队(1979)依据南京     

论浙皖边界地区“黄龙灰岩”下部花石山白云岩的时代

一、前言 黄龙灰岩自1930年李四光等创立以来,一向包括白云岩段在内,其时代为中石炭世经多年的详细研究,建立了生物化石带。但1964年以前,在白云岩段内一直未获生物化石,对白云岩的时代也无争议。64年以后,先后在不同地区白云岩段内采获了不少生物化石,据化石门类,属种之异同,对白云岩段时代归属则产生了争论。 笔者在皖南及浙北工作二十多年,于64年即已发现白云岩段内所夹薄层纯灰岩中含(竹蜓)。74年讨论了花石山白云岩时代,定为中石炭世早期,相当欧洲纳缪尔阶B、C两期。     

江西梓山组植物化石新资料

梓山组原称梓山系。最初,,斯行健和陈国达(1942)仅根据其中所出现的大脉羊齿Neuropteris gigantea Sternb.,认为它属中石炭世维斯发期。解放后,斯行健(1958)在描述江西乐平王八山梓山煤系植物—Neuropteris gigantea,Sphenopteris obtusiloba,Rhodea sp。以及新属种Lopinopteris intercalata之后,重申其时代为中石炭世。李星学(1964)描述了江西丰城饶家山梓山组发现的Mariopteris acuta Brongniart forma obtusa Goth.,认为此种植物在欧洲一般限于纳缪尔晚期和维期发早期。     

南京吕家山中生代层地及Lobatannularia植物化石的发现

一、前言 南京附近吕家山一带出露的一套中生代地层,李毓尧等(1935)曾将其中的砂岩层划为侏罗系象山层,而将其南侧之紫红色砂页岩、灰岩误划为下石炭统高骊山系及中石炭统船山灰岩。1964年,南京大学地质系在测制1:5万南京,汤山、上党幅区测报告中,将上述石炭纪地层改划为下一中三叠统青龙群及上三叠统黄马青组。1977年,安徽省区测队在1:20万南京幅区调报告中,又将上述地层改划为中三叠统徐家山组。 1985年,杨松生,蔺雨时发表“南京附近的高骊山组”一文,复将上述紫红色砂页岩划为下石炭统高骊山组,并在上部的灰色砂泥岩中采得一些植物化石,定其为古生代之属种:Suble pidodendron sp., Archaeocalamites sp., Calamites sp., Sphenophyllum sp., Loncho pteris sp., Rhodeas sp., Pecopteris cf. plumosa,Mario-     

粤北228铀矿床U-Pb同位素体系演化特征及成矿模式探讨

<正> 本矿床为产在石炭、二迭系碳酸盐沉积建造中的一个铀矿床,属于碳-硅-泥岩类型。铀矿化严格受层位和构造破碎带的联合控制,主要赋存在下石炭统梓门桥段下亚段(C_1dZ~α)和上二迭统龙潭组中段(P_2L~2)地层中。含矿层的沉积(音页)律表现为粉砂岩—页岩—含泥炭质灰岩(及白云岩)—页岩—粉砂岩,为氧化-还原交替变化的沉积环境。同时,铀的富集与破碎带的宽度和破碎程度密切相关。     

浙江省上石炭统-中二叠统生物地层划分进展

本文划分论述了浙江省上石炭统—中二叠统16条化石带（其中11条为新建化石带）,对比研究结果表明它们分布于老虎洞组、黄龙组、船山组、梁山组、栖霞组、孤峰组、龙潭组下部的地层,可分别与滑石板阶、达拉阶、逍遥阶、紫松阶、隆林阶、栖霞阶、祥播阶、茅口阶、冷坞阶等9个阶对比。探讨研究了上石炭统底界、下二叠统底界和中二叠统底界;指出上石炭统未见底,缺失罗苏期的沉积;下二叠统底界位于Sphaeroschwagerina subrotunda带之底,以Sphaeroschwagerina属的始现作为底界的标准;石炭—二叠系界线位于Triticites subcrassulu筵带与Sphaeroschwagerina subrotund筵带之间;中二叠统的底界位于Orthotichia chekiangensis腕足组合带之底,以Orthotichia chekiangensis的始现作为中二叠统底界的标准。进一步论证了船山组是一个跨越石炭—二叠系界线的岩石地层单位,下部归属上石炭统逍遥阶,中部归属下二叠统紫松阶和上部归属下二叠统隆林阶。     

安徽巢县老虎洞白云岩的时代归属及其穿时特征

安徽巢县南部地区,上石炭统黄龙组与下石炭统和州组之间普遍发育一套白云岩(图1)。夏广胜等(1980)称之为和州组上段,时代划入早石炭世晚期,并将其与宁镇地区的老虎洞白云岩对比。笔者等在进行1:5万巢县幅区域地质调查时,对该段地层系统测制了剖面,采获丰富的珊瑚、(竹蜓)类化石,现将资料及我们的看法列后,供讨论参考,文中(竹蜓)类由南京地质古生物研究所张遴信鉴定,珊瑚由我队齐敦伦鉴定,在此致谢。     

长江中下游、浙西地区的上石炭统

本文系统阐述了区内上石炭统地层的分布范围、岩性特征、厚度变化及所含生物群面貌。     

A new captorhinid reptile, Gansurhinus qingtoushanensis, gen. et sp. nov., from the Permian of China

Captorhinids, a clade of Paleozoic reptiles, are represented by a rich fossil record that extends from the Late Carboniferous into the Late Permian. Representatives of this clade dispersed from the equatorial regions of Laurasia into the temperate regions of Pangea during the Middle and Late Permian. This rich fossil record shows that there was an evolutionary trend from faunivorous to omnivorous and herbivorous feeding habits within this clade. The discovery of well-preserved captorhinid materials in the Middle Permian of China allows us to determine that the new taxon, Gansurhinus qingtoushanensis, gen. et sp. nov, is a member of Moradisaurinae, a clade of captorhinids with multiple tooth rows arranged in parallel. The presence of this moradisaurine in the Middle Permian of south central Asia leads us to suggest that paleogeographic changes during the Permian, with part of what is today China becoming a large peninsula of Pangea, allowed these early reptiles as well as other terrestrial vertebrates to extend their geographic ranges to this region of the Late Paleozoic supercontinent.     

赣西北地区石炭系研究的新进展

在赣西北地区石炭纪沉积学及生物地层学研究中取得如下新进展.1.上石炭统原黄龙组顶部首次:采获船山组标准化石,(?)Eoparafusulina sp.,证实了本区有晚石炭世马平期沉积一船山组的存在。2.黄龙组下部白云岩段,发现牙形刺:Idiognathoides sinuatus-Idiognathodus delicatus 动物群 及(?)类:Verella cf.prolixa,Ozawainella pseudorhomboidalis等,为白云岩段时代归属威宁期提供了化石依据。3.作者认为本区黄龙组底部零至三十余米的一套碎屑岩主要为石炭纪威宁期始时海侵初期的滨海相或浅海滞留沉积,与其上白云岩为连续沉积。     

A new bolosaurid parareptile, Belebey chengi sp. nov., from the Middle Permian of China and its paleogeographic significance

A new bolosaurid parareptile, Belebey chengi sp. nov., is described from Dashankou, Gansu Province, China, a Middle Permian locality which is known mostly for its therapsid fauna. The material consists of well-preserved mandibular and anterior skull remains and currently represents the largest and latest surviving member of Bolosauridae. Phylogenetic analysis of bolosaurid interrelationships, the first analysis of any clade of Early Permian parareptiles, indicates that the new taxon groups consistently with the other (Russian) members of the genus Belebey, and forms the sister clade to the genus Bolosaurus from North America. The Early Permian Eudibamus cursoris from Germany falls into the basal most position within Bolosauridae. Our analysis also shows that the split between the main bolosaurid lineages must have occurred near or before the Permo-Carboniferous boundary and that the paleo-equatorial region of Laurasia probably served as the center of origination for these parareptiles. A similar pattern can be found in other clades of Paleozoic amniotes, suggesting that this may be the general trend in early amniote evolution.     

Middle-Eocene artiodactyls from Shanghuang (Jiangsu Province,Coastal China) and the diversity of basal dichobunoids in Asia

A new assemblage of basal dichobunoid artiodactyls from the middle-Eocene Shanghuang fissure fillings includes the diacodexeid Jiangsudon shanghuangensis gen. and sp. nov., a new species of the lantianine dichobunoid Elaschitotherium, Elaschitotherium crepaturus sp. nov., and an indeterminate suoid which is presently the earliest record of this clade. Diacodexeids are also represented by two forms provisionally referred to cf. Diacodexis sp. and to an indeterminate Diacodexeidae, respectively. The occurrence of diacodexeids in Shanghuang contrasts with the early and earliest middle-Eocene chronological range of the family in Europe and North America and suggests that the stratigraphic range of the family in Asia extends up to the middle Eocene. This may reflect particular habitats in coastal China that may have been relatively stable during the early and middle Eocene, thus preserving forest-dwelling artiodactyls that became extinct in the other Holarctic regions. Compared to other supposedly coeval North American, European, and Asian faunas, the Shanghuang mammalian assemblage is most similar to early Uintan faunas of North America but is also remarkable in recording forms close to taxa that are characteristic of the Wasatchian and Bridgerian North American Land Mammal Ages. The Irdinmanhan age of the Shanghuang fauna is supported by the mammalian assemblage recovered from the fissure D, but an Arshantan age cannot be completely ruled out at this point. Although the Shanghuang assemblage is biased towards preservation of small components of the mammalian fauna, the Shanghuang fauna provide an important and unique window into the Eocene diversity and early evolution of cetartiodactyls in eastern Asia.     

A giant termite from the Late Miocene of Styria, Austria (Isoptera)

A giant termite is described and figured from the Late Miocene of the Styrian Basin in southeastern Austria. Gyatermes styriensis gen. n. et sp. n. is represented by a relatively complete forewing, with basal scale. The fossil approximates in size the largest of all termites today and is the largest fossil termite on record. The presence of this species in the Late Miocene fauna of Europe indicates that climatic conditions were appropriate for the persistence of species and colonies requiring relatively stable, warm conditions. The genus is primitive in overall features but shares some similarity with the dampwood termites.     

A structural intermediate between triisodontids and mesonychians (Mammalia, Acreodi) from the earliest Eocene of Portugal

A new mammal, Mondegodon eutrigonus gen. et sp. nov., is described from the earliest Eocene locality of Silveirinha, Portugal. This species shows dental adaptations indicative of a carnivorous diet. M. eutrigonus is referred to the order Acreodi and considered, along with the early Paleocene North American species Oxyclaenus cuspidatus, as a morphological intermediate between two groups of ungulate-like mammals, namely, the triisodontids and mesonychians. Considering that triisodontids are early to early-late Paleocene North American taxa, Mondegodon probably belongs to a group that migrated from North America towards Europe during the first part of the Paleocene. Mondegodon could represent thus a relict genus, belonging to the ante-Eocene European mammalian fauna. The occurrence of such a taxon in Southern Europe may reflect a period of isolation of this continental area during the Paleocene/Eocene transition. In this context, the non-occurrence of closely allied forms of Mondegodon in the Eocene North European mammalian faunas is significant. This strengthens the hypothesis that the mammalian fauna from Southern Europe is characterized by a certain degree of endemism during the earliest Eocene. Mondegodon also presents some striking similarities with an unnamed genus from the early Eocene of India which could represent the first Asian known transitional form between the triisodontids and mesonychians.     

内蒙古锡林浩特Ⅰ型花岗岩的时代及构造意义

在内蒙古锡林浩特水库地区出露的花岗岩确定为I型花岗岩,具有较高的Cr、Co、Ni丰度。Ca、Al含量和N2O/K2O比值较高,Fe、Mg含量较低。微量元素蛛网图中显示出明显的Nb、Ta、P、Ti负异常。在SiO2-K2O及AFM图中,花岗质岩石投在钙碱性系列区;在构造环境判别图中,花岗质岩石样品都投在火山弧+同碰撞花岗岩区。锆石测年结果显示平均年龄为317.0±4.0Ma,属晚石炭世。这套晚石炭世岛弧花岗岩的存在,表明加里东期古亚洲洋并未完全关闭,晚石炭世时仍然存在洋壳的俯冲消减事件。从区域上看,是北侧的贺根山洋盆向南俯冲的结果。     

Last Glacial mammals in South America: a new scenario from the Tarija Basin (Bolivia)

The chronology, sedimentary history, and paleoecology of the Tarija Basin (Bolivia), one of the richest Pleistocene mammalian sites in South America, are revised here based on a multidisciplinary study, including stratigraphy, sedimentology, geomorphology, paleontology, isotope geochemistry, and ¹⁴C geochronology. Previous studies have indicated a Middle Pleistocene age for this classic locality. We have been able to obtain a series of ¹⁴C dates encompassing all the fossil-bearing sequences previously studied in the Tarija Basin. The dated layers range in age from about 44,000 to 21,000 radiocarbon years before present (BP), indicating that the Tarija fauna is much younger than previously thought. Glacial advances correlated to marine isotopic stages (MIS) 4 and 2 (ca. 62 and 20 ka BP, respectively) are also documented at the base and at the very top of the Tarija–Padcaya succession, respectively, indicating that the Bolivian Altiplano was not dry but sustained an ice cap during the Last Glacial Maximum. The results of this multidisciplinary study enable us to redefine the chronological limits of the Tarija sequence and of its faunal assemblage and to shift this paleontological, paleoclimatological, and paleoecological framework to the time interval from MIS 4 to MIS 2.     

黔中九架炉、祥摆、旧司组特征及其地质意义──以乌当地区为例

在贵阳乌当断层南北两侧 ,下石炭统九架炉组、祥摆组和旧司组的分布和沉积特征存在明显的变化。九架炉组基本分布于乌当断层北西侧 ,祥摆组由北向南的沉积环境向浅海相呈有规律的变化 ,旧司组则仅在乌当断层南侧分布。这些地层的分布规律、沉积环境的变化说明了乌当断层为黔中隆起南侧边缘断层 ,且该断层自早古生代形成后 ,为一多期次活动断层。