藏南江孜地区古近纪甲查拉组孢粉组合及古环境分析

甲查拉组位于藏南特提斯喜马拉雅北带的江孜盆地,是江孜地区的最高海相地层,被视为新特提斯洋关闭时代的主要证据。通过对甲查拉组剖面的孢粉分析,自下而上划分为3个孢粉组合带:1 Ulmipollenites minor+Ulmoideipites-Myricipites组合带;2 Quercoidites-Caryapollenites组合带;3 Abiespollenites-Betulaceoipollenites+Betulaepollenites组合带。甲查拉组孢粉植物群揭示出其沉积自晚古新世开始,其沉积结束可能延续到早渐新世。推测晚古新世—早始新世为温暖湿润的暖温带或亚热带气候,始新世中晚期为温暖、潮湿的亚热带气候,早渐新世为温和湿润的暖温带气候。     

俄罗斯阿穆尔河东部上泽亚坳陷始新统孢粉

报道一个产于上泽亚(Uupper Zeya)坳陷(东经129-130°,北纬54-55°)东南部,保存良好的化石孢粉植物群.孢粉组合中裸子植物花粉居统治地位,占总数的53.4%,其中Taxodiaceae占36.3%,松科仅占5%.被子植物花粉占39.9%,多为葇荑花序类,如胡桃科、桦木科、山毛榉科等;同时还有不少反映温暖气候的分子,如Liquidambar,Balsaminaceae,Magnoliaceae,Nyssaceae等.孢子植物占21%.这样的孢粉植物群代表了潮湿温暖的温带气候.孢粉学至今在坳陷区内仍是人们用以确定地层时代的唯一依据.Pistillipollenites macgregorii,Anacolosiditessuplingensis,Ulmoideipites tricostatus及U. crempii等的出现可以确定含孢粉地层的地质时代属于中-晚始新世.斯涅日诺戈斯克产煤区中晚始新世沉积中的孢粉层位与普里阿姆尔耶,雅库提亚和亚洲东北部的同期沉积相当.     

川西高原白垩纪孢粉组合的发现及其意义

横断山地区和川西高原金沙江两岸广泛分布红色碎屑沉积,自德格县错阿乡的红色沉积之上部深褐灰色含铜砂岩中获得了相当数量的孢子花粉化石。在该孢粉组合中稀指孢子居绝对优势,被子植物花粉极少,推测其地质时代应属晚白垩世,可能为晚白垩世早期。因此,当前孢粉组合的发现证明了川西高原横断山地区不仅有第三纪红层,也存在白垩纪红层。组合中含有大量的稀指蕨隐孱和少量麻黄花粉,而不同见喜湿植物的孢子花粉,推测该地区白恶霸     

塔里木盆地二叠系孢粉组合及生物地层学*

首次系统地研究了塔里木盆地二叠系孢子花粉，讨论了盆地各地层分区孢粉组合特征，建立了从早二叠世至早三叠世早期的6个孢粉组合带，阐述了各组合带孢粉学特征。依据对盆地二叠纪孢粉植物群组成分子的分析及其与国内外相关孢粉组合的比较研究，将盆地孢粉植物群分为3个发展阶段，即：早二叠世早、中期的欧美型植物群，早二叠世晚期至晚二叠世早期的安加拉欧美混生型植物群和晚二叠世中、晚期的安加拉型植物群。文中还从孢粉地层学角度论述了沙井子组、杜瓦组和普司格组的地质时代以及二叠/三叠系界线等问题。描述孢粉25属33种（含2新种）。     

青藏古植被的演变与青藏高原的隆起

西藏北部,在早石炭世晚期位于欧亚古陆的南缘,其植物群与当时印度次大 陆的不同。在晚二叠世,藏北属华夏植物区(即大羽羊齿植物区);印度河-雅鲁 藏布江大断裂带以南的地区出现舌羊齿植物群, 因而属冈瓦纳古陆的一部分。 到晚三叠世藏北植物群的面貌与我国西南同时代的植物群相似,与印度的则迥 然不同,显示藏北晚三叠世的植物群与南半球植物群也没有直接联系。 柴达木 侏罗纪植物群和拉萨附近早白垩世植物群与北半球的植物群有密切的关系。日 喀则晚白垩世植物群和阿里早始新世植物群也是如此。他们与印度德干玄武岩 夹层中出现的古新世植物群和印度北部始新世植物群也没有联系。 当时,西藏 的北部和南部属于两个不同的古陆,欧亚古陆和冈瓦纳古陆。 两者之间应有一 个很宽阔的特提斯海。因而,青藏的植物化石强有力地支持了大陆漂移的观点, 印度地块在晚侏罗世—白垩纪时是由非洲东南隅分离向北漂移,到始新世才与 亚洲连接,成为现在的南亚次大陆。 欧亚大陆与印度地块的接合线或许就是印 度河－雅鲁藏布江大断裂带。 　　从晚石炭世到早始新世的植物群的性质上看,藏北地势多半低洼。 中新世时,西藏中部和北部的植被是以落叶阔叶林为主,虽然某些地区有一 些常绿树存在,反映在中新世以前西藏中部和北部的地面已经上升到一定的程 度。在上新世时,藏北的常绿阔叶林逐渐减缩。柴达木盆地的植被转变成落叶 阔叶林－针叶林,以后转变成草原和半荒漠或荒漠,显示西藏和青海的地面进一 步抬升。 　　到晚上新世,藏北和青海的植被再行演变。然而,喜马拉雅地区的植被仍然 具有常绿栎林和雪松林。可能那时喜马拉雅山不像现在那么高。印度洋的季风 可以吹过喜马拉雅山,没有高山的阻碍。 　　第四纪是青藏山系和青藏地面上升最剧烈的时期。此时藏北已无常绿阔叶 树的存在。 到第四纪后期西藏大部分地区的植被逐渐演变为高寒荒漠。 最后, 青藏高原变成现在的情况。     

河南东濮地区晚始新世至渐新世轮藻植物群及其古环境探讨

东濮地区晚始新世沙河段组四段上部至三段轮藻植物群生存于含钙量高的咸化型水体中,它们的横向分布反映了湖盆中部存在着一个ＮＮＥ向的隆起地带。早渐新世沙河街组二段轮藻植物群生长于含钙量低的淡水水体中,它们的横向分布反映了湖盆中部古地形自南向北高低相间。晚渐新世东营组轮藻植物群生存于含钙量低的淡水水体中,它们的横向分布反映了湖盆的古地势较为平坦。     

广西百色第三纪哺乳动物群与气候变迁

在广西百色共发现了三个层位:晚始新世早期的洞均组,晚始新世晚期的那读组和早渐新世的公康组。它们的哺乳动物的种类数目分别为14,27和ll,而其南方类型的百分含量则分别为50,77.8和54.5。故在晚始新世早期或早渐新世,气候较凉;而在晚始新世晚期,气候较暖。这是与北美的情况相类似的。     

鄂西荆门-当阳盆地九里岗组几种丁菲羊齿植物

本文报道了鄂西荆门-当阳盆地晚三叠世九里岗组几种丁菲羊齿(Thinnfeldia)植物,即雅致丁菲羊齿[(新种)Thinnfeldia elegans(sp.nov.)]、南漳丁菲羊齿[(新种)Thinnfeldiananzhangensis(sp.nov.)]、远安丁菲羊齿[(新种)Thinnfeldia yuaanancnsis(sp.nov.)],并对九里岗组植物群的性质进行了扼要的讨论,初步认为该植物群具有我国南、北晚三叠世两个植物群的过渡性质。     

东海陆架盆地西南部始新世孢粉

通过对东海陆架盆地西南部台北拗陷始新统之瓯江组、温州组和平湖组的孢子和花粉的研究,本区始新统可分为两个孢粉组合:Taxodiaceaepollenites-Caryapollenites triangulus-Aquilapollenites spinulosus组合(早始新世)和Retitricolpites-Retitricolporites组合,后者又分为两个亚组合,分别代表中始新世和中始新世晚期或/至晚始新世早期的孢粉植物群。孢粉组合反映早始新世的植物群主要由杉科、胡桃科和完斗科组成,指示暧湿的、近现今的中南亚热带气候;中晚始新世孢粉植物群具有明显的现代性,并有较多南亚热带成份加入,指示更趋暖热的气候环境,其后半期有较多指示干旱气候的分子出现,表明曾一度受到干旱气候的影响。     

RPB2序列的贝叶斯分析估计梅衣科部分谱系分化时间

以树发属(Alectoria)化石为校正点,使用RPB2序列和BEAST分析方法估计梅衣科部分类群的分化时间。梅衣科地衣部分谱系的分化发生在白垩纪、古新世到始新世和渐新世;主要属内辐射则发生在晚始新世、早渐新世,并延续到中新世和上新世早期。估计的主要谱系分化时间与古气候条件及古地质区域分支图相呼应。     

The Tropics as Reservoir of Otherwise Extinct Mammals: The Case of Rodents from a New Pliocene Faunal Assemblage from Northern Venezuela

We report a new vertebrate assemblage from the Pliocene Vergel Member of the San Gregorio Formation in northwestern Venezuela, which includes Crocodylia and Testudines indet., toxodonts, at least four species of xenarthrans of the Dasypodidae, Pampatheriidae, Glyptodontidae and Megatheriidae, and rodents. The last are Cardiatherium, cf. Caviodon (Hydrochoeridae), Neoepiblema (Neoepiblemidae), and what is here described as a new genus of a low-crowned octodontoid. cf. Caviodon is the first cardiomyine for northern South America. The rodent assemblage resembles in its ecological composition those of the late Miocene (Huayquerian) from the “Mesopotamian” of Argentina and the Acre region in Brazil, with partially overlapping systematic composition. The stratigraphic position of the San Gregorio Formation and mammals other than caviomorphs suggest a late Pliocene age for these sediments, implying the endurance of rodent taxa beyond their biochron in southern South America.     

Origines du peuplement mammalien en Afrique du Nord durant le miocène terminal

The late Miocene North African mammalianassemblage is considered here from three viewpoints: survivals, extinctions, and immigrations. The Eurasiatic affinities of the large mammals slightly prevail over the Ethiopian affinities. Amongst the North African large mammals, 4 to 8 taxa are Eurasiatic immigrants, while 4 to 6 are of Subsaharian origin. Contrarily, the micromammalian fauna is highly endemic, with only one species, a murid (Paraethomys miocaenicus), considered here as being related to an Asiatic form (Karnimata darwini). Our study of Eurasian and African Miocene faunas reveals that during the late Astaracian-early Turolian interval, the Saharo-Arabic belt permitted very little latitudinal faunal exchanges. However, during the middle and late Turolian such faunal exchanges became frequent. The micromammal record unequivocally indicates that a brief period of faunal exchange occurred between Africa and western Europe at the end of the Miocene, corresponding with the Messinian Salinity Crisis. The increased intercontinental faunal exchange between Africa and Eurasia during the late Miocene coincides with, and counterbalances the extinction of more than 10 taxa at the Mio/Pliocene boundary.     

Late Miocene continental biota in Northeastern Patagonia (Península Valdés, Chubut, Argentina)

A new vertebrate faunal assemblage was recently discovered from the uppermost part of the late Miocene Puerto Madryn Formation. These deposits crop out along the southwestern coast of the Península Valdés area near Punta Delgada (Chubut Province, Argentina). The exhumed vertebrate fauna includes a range of fish, bird and mammal taxa, of which the latter are most varied and abundant. The new findings represent the first record of continental fossil vertebrates in the Puerto Madryn Formation and this is the first assemblage of late Miocene continental vertebrates recorded to the south of Río Negro Province. It also includes the southernmost record of Hydrochoeridae rodents, Dendrocygninae birds and Loricariidae fishes. The mammals suggest that the fossil-bearing sediments are Huayquerian in age. The climate during the accumulation of late Miocene deposits in this region is inferred to have been warmer and seasonally drier than that of today.     

松辽盆地来D13井地层划分对比研究

岩石组合特征和同位素数据表明,松辽盆地来D13井137.0—142.0m井段属于早白垩世晚期(Aptian—Albian期)营城组。104.2—137.0m井段光山核桃粉(Caryapollenites simplex)-拟榛莫米粉(Momipites coryloides)-朴粉未定种(Celtispollenites sp.)-具缘铁杉粉(Tsugaepollenites igniculus)组合特征可以与前人的大安组孢粉组合特征对比,反映的都是暖温带至北亚热带中生气候,而与晚白垩世嫩江组的孢粉组合特征截然不同,应该确定为早中新世晚期至中中新世的大安组。54.2—104.2m井段小蒿粉(Artemisiaepollenites minor)-拟桦粉未定种(Betulaceoipollenites sp.)-枥粉未定种(Carpinipites sp.)-水龙骨单缝孢未定种(Polypodiaceaesporites sp.)组合特征可以与前人的泰康组孢粉组合特征对比,反映的都是暖温带至北亚热带中生偏旱气候,这与前人依据岩石组合特征确定为泰康组的结论一致,孢粉组合时代分析表明,该井段沉积的时间为晚中新世至上新世初期。研究结果丰富了松辽盆地新近纪孢粉地层学内容,为松辽盆地西部斜坡区井下新近纪孢粉地层学对比提供了新资料,也为邻区新近纪生物地层学对比以及古植被和古气候分析提供了新的依据。     

Late Neogene nannofossil biostratigraphy and paleoceanography of the northeastern Gulf of Mexico and adjacent areas

Two 305 m cored sections from the northwest Florida continental shelf contain a nearly complete record of late Neogene hemipelagic sedimentation. One of the sites, south and east of De Soto Canyon, is isolated from terrigenous sediment except for sediment transported in suspension. This site contains a continuous record from the late Miocene to the Recent. The second site, on the western rim of De Soto Canyon, is more expanded and continuous from the late Pliocene to the Recent. A hiatus separates the late Pliocene from the middle Miocene. Six prominent nannofossil biohorizons were recognized within the Pleistocene, seven within the Pliocene, and three within the Miocene; in addition one biohorizon marks the base of the Pleistocene and another the base of the Pliocene.Nearly all carbonate in the sediment is pelagic. Terrigenous detrital sedimentation was controlled by glacioeustatic sea level fluctuations during the Pleistocene, and sea level changes are probably responsible for fluctuations in the ratio of pelagic carbonate to clayey detritus in pre-Pleistocene sediments also. Carbonate content, coarse fraction percent, and relative abundances of environmentally sensitive nannoplankton species suggest important paleoceanographic changes in the northeastern Gulf of Mexico and adjacent areas. Fluctuations in the relative abundance of the solution-resistant coccoliths of the genusCyclococcolithus indicate that waters at a depth of 600–1000 m were more corrosive during the late Miocene than they are today. The decrease in carbonate dissolution during the late Miocene probably was a response to gradual constriction of the Central American passage and the consequent restriction of flow of corrosive water from the Pacific. Short term fluctuations in dissolution during the Pliocene and Pleistocene are related to climatic cycles.Productivity variations in the surface waters, recorded mainly by the relative abundance of small and large morphotypes of closely related coccolith species, indicate that productivity increased during the Pliocene, but the most dramatic change — a major oceanwide increase in productivity — occurred during the Pleistocene, during and just prior to the Jaramillo magnetic event about 0.9 m.y. ago. Surprisingly the late Miocene Messinian event did not leave a significant imprint in the northeastern Gulf of Mexico.     

Presence of Hypolagus Dice, 1917 (Mammalia, Lagomorpha) in the Neogene of the Balearic Islands (Western Mediterranean): Description of Hypolagus balearicus nov. sp.

In this paper we describe a new species of Hypolagus coming from an early Pliocene karstic deposit near Caló den Rafelino (Manacor, Mallorca). It represents the westernmost European record for the genus. The faunal assemblage of this deposit represents an early phase of the second insular faunal episode of Mallorca, related with the Messinian regressive episode (latest Miocene). Although the postcranial are relatively robust, the size of all these elements is included in the range of continental leporids. It is unknown if they display significant allometric changes, as occurred in other insular leporids. p3 is small and displays a markedly trapezoidal outline and a deep hypoflexid (between 54 and 56% of the total tooth width). The presence of Hypolagus in the Neogene of the Balearic Islands is in agreement with the faunal scenario for the European continent during the late Miocene and the Pliocene, where this genus is abundant and widely distributed.     

Edaphic and climatic history has driven current dung beetle species pool and assemblage structure across a transition zone in central South Africa

We investigate biogeographical, regional and sub‐regional‐scale responses of scarabaeine dung beetles to late Cenozoic changes in edaphic and climatic character that created a Savanna/Karoo transition zone in the Northern Cape, South Africa. Across a 50 200 km² study area, the Northern Cape species pool comprised six biogeographical groups defined from distribution across southern Africa. These species groups contributed in different proportions to five regional assemblages defined from structural differences across the transition zone. Towards transition zone peripheries, regional assemblage structure was more strongly correlated to sandiness dating from Miocene to Pliocene deposition (Kalahari), aridity dating from Pliocene to Pleistocene climatic change (Bushmanland Karoo), or cooler temperatures dating from Miocene to Pliocene uplift (Upper Karoo). Correlates of sub‐regional assemblages trended to intensification of dominant drivers towards regional peripheries. Drivers of central transition zone, regional assemblages (‘Gariep Karoo’, ‘Gariep Stony Karoo’) showed no dominance. Biogeographically, endemism dominates the Northern Cape transition zone: south‐west arid groups in Nama Karoo regions; Kalahari plus north‐east savanna groups in the Kalahari. Regionally, transition drives assemblage structure: unique variance, 60% in the Kalahari, 21–30% in four Nama Karoo regions; shared variance (overlap), 25–65% between Kalahari and warmer Karoo regions, 11–71% between mainly cooler Karoo regions.     

泥河湾盆地上新世小哺乳动物生物地层学及相关问题讨论

在泥河湾盆地稻地组与壶流河组、蔚县组命名剖面上分别筛洗小哺乳动物化石。其中花豹沟剖面选取 3个层位 ,发现小哺乳动物化石 1 0种 ;稻地剖面 6个层位 ,发现化石 2 5种。结合小哺乳动物化石组合 ,以及岩石地层追索对比 ,认为壶流河组与蔚县组从岩性上无法分开 ,应予合并 ,保留蔚县组 ;稻地组与蔚县组为同时期沉积 ,二者之间存在一定的相变关系 ,建议废止稻地组 ;仅保留蔚县组作为泥河湾组之下风成红黏土之上的岩石地层单位 ,其时代为中上新世晚期至晚上新世。     

New observations on the Late Miocene–Early Pliocene Lutrinae (Mustelidae: Carnivora,Mammalia) from the Middle Awash,Afar Rift,Ethiopia

New observations on the Late Miocene and Earliest Pliocene mustelids from the Middle Awash of Ethiopia are presented. The Middle Awash study area samples the last six million years of African vertebrate evolutionary history. Its Latest Miocene (Asa Koma Member of the Adu-Asa Formation, 5.54–5.77 Ma) and Earliest Pliocene (Kuseralee and Gawto Members of the Sagantole Formation, 5.2 and 4.85 Ma, respectively) deposits sample a number of large and small carnivore taxa among which mustelids are numerically abundant. Among the known Late Miocene and Early Pliocene mustelid genera, the Middle Awash Late Miocene documents the earliest Mellivora in eastern Africa and its likely first appearance in Africa, a new species of Plesiogulo, and a species of Vishnuonyx. The latter possibly represents the last appearance of this genus in Africa. Torolutra ougandensis is known from both the Late Miocene and Early Pliocene deposits of the Middle Awash. The genus Sivaonyx is represented by at least two species: S. ekecaman and S. aff. S. soriae. Most of the lutrine genera documented in the Middle Awash Late Miocene/Early Pliocene are also documented in contemporaneous sites of eastern Africa. The new observations presented here show that mustelids were more diverse in the Middle Awash Late Miocene and Early Pliocene than previously documented.     

Late Miocene biota from the Abad Member of the Carboneras-Nijar Basin (Spain,Andalusia): A bathyal fossil assemblage pre-dating the Messinian salinity crisis

Marly sediments of the early Messinian Abad Member of the Turre Formation from the northeastern sector of the Carboneras-Nijar Basin (southern Spain) have yielded a rich fossil assemblage, of which 60 taxa are documented herein. Besides nannoflora and microfauna, this assemblage includes the first autochthonous macrofauna described from the Abad Member. Based on the calcareous nannofossil assemblage, in particular the occurrence of the zonal index taxon Amaurolithus primus, the sediments are assigned to the Mediterranean calcareous nannofossil zone CNM17, corresponding to the latest Tortonian to earliest Messinian interval. This matches the age range generally reported for the Abad Member. Palaeoecological evidence from calcareous nannofossils (20 autochthonous taxa), planktic and benthic foraminifera (12 taxa), Porifera (3 taxa), Octocorallia (Keratoisis), Serpulidae (4 taxa), Bivalvia (5 taxa), Gastropoda (2 taxa), Brachiopoda (7 taxa), Cirripedia (Faxelepas) and Vertebrata (5 taxa) indicates an upper bathyal environment with an influx of neritic elements for the Abad Member near Carboneras. Additionally, several faunal components may represent allochthonous/parautochthonous elements from adjacent habitats, which were transported into the deep marine setting by turbiditic mass flows. Although similarities exist, the fossil assemblage from the marls is compositionally significantly different from the biota previously documented from a nearby exposed olistostrome, the ‘red breccia’. Similar fossil assemblages from the Mediterranean have so far mainly been reported from the Pliocene-Pleistocene of southern Italy and Greece. The Carboneras fauna thus adds to our knowledge of the development of these habitats and their biota prior to the Messinian salinity crisis. Beyond the novel palaeoenvironmental data, the range of the dyscoliid brachiopod Ceramisia meneghiniana, previously known only from the Pliocene of Italy, is extended to the Miocene of Spain. The cirripede crustacean Pycnolepas paronai De Alessandri, 1895 is transferred to the hitherto monospecific genus Faxelepas Gale, 2015, whereby the range of the latter (previously Maastrichtian to Danian) is extended to the late Miocene.