Studies in Neotropical paleobotany. XI. Late Tertiaryvegetation and environments of southeastern Guatemala: palynofloras fromthe Mio-Pliocene Padre Miguel Group and the Pliocene HerreriaFormation

Plant microfossils are reported from the late Tertiary Padre MiguelGroup and the Pliocene Herrería Formation of southeasternGuatemala. The most abundant palynomorphs are cf. Acrostichum(maximum 45%), Cyperaceae (29%), cf. Antrophyum(27%), monolete fern spores (16%), and Pinus(11%). Pollen grains of Picea, Juglans,Quercus, and Ulmus, primarily from the Padre Miguelflora, reveal the presence of a northern cool-temperate element. Theyounger Herrería flora is more lowland and warm temperate. Inthe absence of evidence for substantially higher elevations, thedifferences between the Neogene and modern vegetation are attributedmostly to climate. MAT (mean annual temperature) is estimated2°-3°C cooler than at present for the Padre Miguel flora,and ～3.5°C warmer for the Herrería flora. There islittle evidence for arid vegetation, and the tropical rain forest wasabsent or poorly represented. These data are consistent with those ofother fossil floras in the region and with trends suggested by isotopicpaleotemperature analysis and global sea-level changes. The Guatemalaassemblages further provide evidence that the current version of thetropical rain forest is recent in origin and has undergone considerablechange in its range and composition throughout the lateCenozoic.     

放射虫化石及地体对比研究

放射虫是一种分布广、区域对比作用大,具有硅质骨格和外壳的远洋,浮游,单细胞微体动物,放射虫化石研究的进展,作为新的地层时代的鉴定标志,在对构造活动带的研究中发挥了重要作用。北美西部及环太平洋构造带的放射虫研究成果,明确了这些地区的地层层序和构造发展史,从而表明,放射虫化石已不单单是古生物学的研究对象,而是地层层序学和构造地质学研究的一个不可缺少的重要方法之一。在对中国东北那丹哈达地体和日本美浓地体     

NEOGENE MAMMALIAN BIOSTRATIGRAPHY IN CHINA:PAST,PRESENT,AND FUTURE

INTRODUCTIoNThedevelopmentoftheNeogenebiostratigraphyofChinawasoneoftheearliestgoalsoftheCenozoicResearchLaboratoryoftheGeologicalSurveyofChina,pre-decessoroftoday'sInstituteofVertebratePaleontologyandPaleoanthropologyaVPP).Therationaleforsuchstudies1iesintheuniversalobjectiveofestablishingthenatureandtempooffaunalchangeinaregionandinadjacentregionsthatarelinkedzoogeographically.Eventuallythedataareusedtoincorporatelocaleventsintotheglobalhistoryoffaunalchange.Besidesthisgoal,thereis…     

氧同位素：追踪陆架海沿岸水团变化的良好标志

对于陆架海而言除了冰体积效应,温度效应外,还有由于大陆淡水注入引起的,使δ＾１８Ｏ值负向偏移的效应,而且在低海平面时期,当沿岸水团盛行时,这种效应起主导作用。笔者将这种效应从广州的盐度效应中分离出来,称为陆架海的负值效应。     

The North American «Hipparion Datum and implications for the Neogene of the Old World

A large sample of skulls and associated dentitions of Cormohipparion sphenodus (Cope, 1889). new combination, is described from Miocene deposits of Nebraska, Colorado, New Mexico, and California. This species is morphologically more advanced than the most primitive species of the genus, C. goorisiMacFadden & Skinner, 1981, and more primitive than a third and more advanced species of this genus. C. occidentale (Leidy, 1856). In several characters such as configuration of the preobrital fossa, size, hypsodonty, shape of protocone, and complexity of enamel plication, C. sphenodus is morphologically similar, and potentially related to, some Old World Vallesian «Hipparion. In addition, based on radiometric calibration of stratigraphic sequences in Nebraska and California, C. sphenodus spans an interval of time from about 13.6 to 11 Ma. Inasmuch as the Old World «Hipparion Datum is calibrated at about 12 Ma, we conclude that C. sphenodus exhibits the morphological and chronological prerequisites to have been directly ancestral to some of these Old World forms.The hipparion horses apparently were a polyphyletic assemblage of several genera, and their biogeographic and biochronologic history is more complex than classically thought. Several dispersal events involving these horses may have occurred between the New and Old Worlds during the late Miocene.     

The history and chronology of siwalik cercopithecids

Cercopithecid monkeys make a comparatively late appearance in the Miocene Siwalik formations of the Indian Subcontinent. The oldest well-dated specimen is a 6.3 MY old colobine, ?Presbytis sivalensis, and it is doubtful that any cercopithecids were present in the Siwalik faunas prior to 7.0 MY, a date that is considerably later than estimates for their appearance elsewhere in Eurasia. Cercopithecines appear later than colobines. Although their temporal ranges are uncertain, cercopithecines evidently were not present before 3.2 MY and possibly not until 2.5 MY. They are represented by three species,?Macaca palaeindica, Procynocephalus subhimalayanus, andTheropithecus delsoni. In the Siwaliks the appearances of colobines and cercopithecines coincide with or follow shortly after major faunal changes that also bring other northern Eurasian and African taxa into the region.     

Tapirus balkanicus nov. sp., nouveau tapir (Perissodactyla, Mammalia) du Turolien de Bulgarie

A new species of Tapiridae, Tapirus balkanicus, is etablished for new material of the Bulgarian Upper Miocene. The comparison with other Neogene tapirids leads us to consider the upper jaw as more characteristic than the lower one for taxonomic determination and study of phyletic relations. A new subgenus, Meyeriscus, is created for Tapirus pannonicus, the most evolved European tapirid.

Résumé

Une nouvelle espèce de tapir est décrite, Tapirus balkanicus du Miocène supérieur de Bulgarie. La comparaison avec les espèces européennes du Miocène moyen (Tapirus teilen) au Villafranchien (Tapirus arvernensis) amènent à privilégier la denture supérieure sur l'inférieure pour la détermination et les rapports phylétiques éventuels entre les espèces. Pour l'espèce la plus évoluée de tous les Tapiridés européens, Tapirus pannonicus est proposé un nom de sous-genre particulier, Meyeriscus nov.     

Dinoflagellate cyst stratigraphy and depositional history of Miocene and Lower Pliocene formations in northern Belgium (southern North Sea Basin)

The occurrence of organic-walled dinoflagellate cysts (dinocysts) in the Diest Formation, a largely decalcified succession with a poor fossil content, and in the adjacent strata of Lower Miocene and Lower Pliocene formations, allowed a biostratigraphic evaluation of these deposits and an assessment of the hiatus between the lithostratigraphic units. The Diest Formation was deposited during Tortonian – Messinian times. Dinocyst biozones defined in the North Sea region and the U.S.A. East Coast are recognised within the Diest Formation, although environmental factors seem to have influenced the presence of some key zonal species in the shallow-marine deposits of northern Belgium. The two members of the Diest Formation studied, i.e., the Dessel Sands and the Diest Sands, appear to be strongly diachronous. The depocentre was located in the Campine area during the early Tortonian and shifted to the area north of Antwerp during late Tortonian to Messinian times. The age assessment provides a correlation of the sequence boundaries of Haq et al. (1987) at the top of the Diest Formation with SB 5.5.     

皖东上第三系玄武岩的非均一、富集型地幔源区─—锶钕同位素证据

本文对皖东郯庐断裂带东侧嘉山—来安地区广泛发育的上第三系玄武岩进行了研究。在以往工作的基础上对该区作了系统的同位素和微量元素地球化学研究；对皖东玄武岩的成因及其地幔源区性质加以探讨。为论证该区存在非均一的富集型地幔提供了地球化学证据。     

新构造运动与渤海海域上第三系大型油气田

在影响渤海海域上第三系大型油气田形成的诸多因素中,上新世—全新世的新构造运动起到了关键作用。渤海湾盆地“向心式”的演化规律（沉降、沉积中心由周围防区向海域逐渐转移）以及晚第三纪以来盆地热流值的逐渐降低,使得海域的烃源岩生、排烃晚;上新世—全新世的新构造运动形成的众多上第三系圈闭为油气聚集提供了有利场所;大量晚期断层与控凹断层、不整合面及砂体相沟通,构成了油气运移的良好通道,并调整和控制了油气的最终成藏。依据构造位置和圈闭成因可将渤海上第三系油气藏划分为３种主要类型：凸起上的背斜型油气藏、凸起—凹陷边缘断阶带的滚动背斜型和断块型油气藏、凹陷中继承性构造和反转构造型油气藏。