西太平洋782A钻孔新生代的有孔虫

大洋钻探工程” 1 2 5航次的 782 A钻孔位于西太平洋菲律宾海东北部 ,井深 4 76.8m。基底为安山岩 ,上覆盖层为中始新统—更新统的沉积层 ,其中保存有低丰度的有孔虫。自下而上可划分出 8个浮游有孔虫带。由于出现 Catapsydrax dissimilis,C.stainforthi为 N5 、N6 带的带化石 ,表明本钻孔存在早中新世的地层。同时由于缺失浮游有孔虫带 P1 5 — P1 6 下部 ,N3上部—N4,N7—N1 1 带的带化石 ,说明在中始新世与晚始新世之间、晚渐新世与早中新世之间、早中新世与中中新世之间存在 3个沉积间断。钻孔中的有孔虫标志本区当时处于温暖亚热带环境。根据不同时期温度的变化 ,可划分出 5个阶段 ,包括 3个偏暖时期和 2个温凉时期。     

塔里木盆地新生代海相沉积问题

基于前人文献,对塔里木盆地新生代海相沉积问题进行梳理,进而探讨该盆地新生代海侵的次数和范围以及海退的时限、原因。研究表明,新生代,塔里木盆地至少经历古近纪的阿尔塔什晚期至齐姆根早期(古新世早期至古新世晚期)、卡拉塔尔期—乌拉根期(始新世中期)、巴什布拉克中期(始新世晚期至早渐新世)等三期海侵;塔里木盆地中新世仍有海相地层这一认识获得广泛认可仍需更多的地质证据来支持。塔里木盆地海侵范围在卡拉塔尔—乌拉根组沉积时期达到最大,向东可达玛扎塔格地区,在盆地北缘和南缘分别可以到达库尔勒以东地区和洛浦县阿其克以东地区。由于受到全球海平面变化和构造运动的共同影响,副特提斯海新生代从塔里木盆地退却的沉积记录包括齐姆根组顶部、乌拉根组顶部、巴什布拉克组第四段和第五段,时间上分别对应于古新世晚期、始新世中晚期和早渐新世。     

内蒙古阿拉善地区的第三系

依据丰富翔实的地层古生物资料,首次在内蒙古西部建立了比较完整的第三纪地层层序：命名或厘订了中始新统乌兰乌珠尔组、上始新统查干布拉格组、下渐新统乌兰塔塔尔组、上渐新统、下中新统乌尔图组、上中新统呼和好来组和上新统昂冈浩特组等７个地层单元;区分出了中始新世乌兰乌珠尔、晚始新世查干布拉格、早渐新世早期克克阿木、早渐新世晚期乌兰塔塔尔、晚渐新世因德里沟、早中新世乌尔图、晚中新世呼和好来和上新世昂冈浩特等８个动物群（组合）。     

Paleobotanical study of a section of the Oligocene–Lower Miocene Maikop Group along the Belaya River above the city of Maikop,Ciscaucasia

A stratotypical section of the Oligocene–Lower Miocene Maikop Group in the valley of the Belaya River above the city of Maikop was studied using a complex paleobotanical method. The hydrological regime of marine basin was specified, especially for the second half of the Early Oligocene, when the basin was brackish. Its desalination began prior to accumulation of the ostracod layers and continued until the beginning of the Late Oligocene. It was once interrupted by short-term ingression of seawater into the Paratethys in the Early Morozkina Balka time. The Karadzhalga and Septarian formations were formed at the end of the Oligocene and in the Early Miocene under frequent oscillations of climate and hydrological regime with accumulation of sediments within the Laba delta front. The complexes of plant microfossils, along with dominant recent marine organic-walled freshwater phytoplankton, contain algae, spores, pollen, and a huge amount of redeposited palynomorphs. They originated from areas of erosion and included Paleogene, Mesozoic, and, locally, Paleozoic taxa.     

内蒙古阿拉善地区的第三系及其动物群

笔者依据丰富翔实的资料,论述了该区第三地层的分布,区划,地层划分沿革,岩性,岩相古地理特征及地质演化史;在地层方面,首次在内蒙古西部建立了比较完整的第三纪地层序列;命名和划分了中始新统乌兰乌珠尔组,上始新统查干布拉格组。下渐新统乌兰塔塔尔组,上渐新统,下中新统乌尔较组,上中新统呼和好来组和上新统昂冈浩特组等６个地层单元,补充界定了查干布拉格组并将其时代厘定为晚始新世;在动物群方面,发现和命名了中始     

菲律宾海盆东北部晚始新世以来放射虫及其古海洋学意义

研究了菲律宾海盆东北部“大洋钻探工程”１２５航次７８２Ａ孔晚始新世以来的放射虫化石。根据Ｓａｎｆｉｌｉｐｐｏ等１９８５年的分带,将研究区自下而上划分为１０个带。讨论了始新世与渐新世、渐新世与中新世、中中新世与晚中新世、中新世与上新世以及上新世与第四纪的界线。研究区存在两个沉积间断,分别位于晚渐新世与早中新世晚期之间和中中新世与晚中新世之间。研究区第四纪放射虫化石仍以暖水分子为主,冷水分子分布较浅。依据放射虫化石分异度曲线得出,晚第三纪以来本区存在５个相对暖水期和５个相对较凉期,渐新世时处于冷水期,这与钙质超微化石复合分异度和碳酸钙含量曲线的变化是一致的。晚渐新世与早中新世晚期之间的沉积间断是由于中新世南极冰盖扩展造成大洋底层洋流活动加剧而形成的。     

The shutdown of an anoxic giant: Magnetostratigraphic dating of the end of the Maikop Sea

Paratethys, the lost sea of central Eurasia, was an anoxic giant during Oligocene – early Miocene (Maikop Series) times. With a size matching the modern-day Mediterranean Sea and a history of anoxic conditions that lasted for over 20 Myrs, the eastern part of this realm (Black Sea-Caspian Sea domain) holds key records for understanding the build-up, maintenance and collapse of anoxia in marginal seas. Here, we show that the collapse of anoxic Maikop conditions was caused by middle Miocene paleogeographic changes in the Paratethys gateway configuration, when a mid-Langhian (Badenian-Tarkhanian) transgression flooded and oxygenated the Eastern Paratethys. We present an integrated magneto-biostratigraphic framework for the early Middle Miocene (Tarkhanian-Chokrakian-Karaganian regional stages) of the Eastern Paratethys and date the lithological transition from anoxic black shales of the Maikop Series to fossiliferous marine marls and limestones of the regional Tarkhanian stage. For this purpose, we selected two long and time-equivalent sedimentary successions, exposed along the Belaya and the Pshekha rivers, in the Maikop type area in Ciscaucasia (southern Russia). We show that a significant but short marine incursion took place during the Tarkhanian, ending the long-lasting Maikop anoxia of the basin. Our magnetostratigraphic results reveal coherent polarity patterns, which allow a straightforward correlation with the time interval 15–12 Ma of the Geomagnetic Polarity Time Scale. The Tarkhanian flooding occurred during a relatively short normal polarity interval that correlates with C5Bn, resulting in an age of 14.85 Ma. The regional Tarkhanian/Chokrakian stage boundary is located within C5ADn at an age of 14.75 Ma and the Chokrakian/Karaganian boundary is tentatively correlated with C5ACn and an age of 13.9–13.8 Ma. Our new Tarkhanian flooding age reveals a paleogeographic scenario that is different from many previous reconstructions. Instead of envisaging marine connections to the Indian Ocean, we show that major changes in connectivity between the Eastern and Central Paratethys seas have caused the influx of marine waters during the Tarkhanian. An increase in marine connectivity with the Mediterranean during a short episode of rapid sea-level rise triggered mixing and ended the widespread anoxia in the Eastern Paratethys. The mixing episode was short-lived (~100 kyr) as the sea-level rise slowed down and connectivity degraded because of tectonic uplift in the gateway area.     

Late Cenozoic development of the Strouma and Mesta fluviolacustrine systems,SW Bulgaria and northern Greece

The Strouma and Mesta are two of the largest rivers that drain across SW Bulgaria and northern Greece into the northern Aegean Sea. Their modern valleys, flanked by Quaternary river terraces, are incised into a diverse landscape, which records the region's complex tectonic history. A network of lacustrine basins existed in the region in the Late Oligocene to earliest Miocene, but was disrupted by thrusting and folding related to Early Miocene transpression. This deformation was followed by a period of erosion, covering most of the Early and Middle Miocene, which probably marked the initiation of the Strouma and Mesta fluviolacustrine system, with geometries unrelated to the older systems. The first clear evidence of these river systems dates from the Middle Miocene (late Badenian to Sarmatian). The systems evolved in the Late Miocene (Maeotian to early Pontian), when lakes existed, characterized by diatomaceous algae and by occasional burial of abundant plant fragments and coal formation. Areas in the south, south of the Kerkini fault, were intermittently submerged beneath the Aegean Sea at this time. Intense localized uplift of horst blocks in late Pontian and Pliocene, associated with crustal extension, resulted in deposition of thick alluvial fans, with tilting of sedimentary successions in adjacent grabens evident by the end of the Pliocene. The highest horsts (Osogovo, Rila, Pirin, and Belasitsa) experienced additional uplift in the Pleistocene, in part as a result of regional uplift and in part through continued normal faulting. Pleistocene climate change also resulted in influxes of glacial and fluvioglacial systems. The present form of the Strouma and Mesta fluviolacustrine systems is thus the result of interplay between crustal extension, regional uplift, and global climate change.     

Structure of the Maikop complex of the Caspian Sea region based on seismic stratigraphic research

The paper reports on the structure of the Oligocene–Lower Miocene Maikop complex of the Caspian Sea and its margin on the basis of seismic and geological data. It is shown that the regional structure of Maikop deposits of Ciscaucasia and the Middle Caspian is characterized by large clinoform sedimentary bodies. New data on formation, structure, and occurrence of clinoforms in Maikop deposits are generalized for the researched region. Two main systems of clinoforms were defined in the Maikop complex: the single large cone located in the Middle Caspian and Eastern Ciscaucasia and the southeastern system of clinoforms located in the area of Kazakh Bay. Structural characteristics and sedimentogenesis of a clinoform formation are revealed using seismic and sequence stratigraphic methods.     

中新生代辽河盆地区域应力场变化及其成因

中新生代辽河盆地的形成和发展受控于多期区域应力场变化。对构造现象、火山活动、层序充填型式等多种实际资料的分析表明：辽河盆地经历了侏罗纪末－白垩纪早期、古新世中后期、始新世中后期、中新世等右旋张扭应力场作用阶段，以及白垩纪晚期－古新世初期、始新世早中期、渐新世、上新世以来等左旋压扭应力场作用阶段。区域应力场变化可以用地球自转速度变化引起的岩石圈板块活动及触发的深部过程来解释，亦与先期构造形迹和盆地边界条件有关。不同区域应力场的转化不仅导致了盆地演化的旋回性，也为辽河盆地及其邻区中新生代多套含油气层系的形成奠定了物质基础。     

Paleogeography of the Upper Rhine Graben (URG) and the Swiss Molasse Basin (SMB) from Eocene to Pliocene

Twenty paleogeographic maps are presented for Middle Eocene (Lutetian) to Late Pliocene times according to the stratigraphical data given in the companion paper by Berger et al. this volume. Following a first lacustrine-continental sedimentation during the Middle Eocene, two and locally three Rupelian transgressive events were identified with the first corresponding with the Early Rupelian Middle Pechelbronn beds and the second and third with the Late Rupelian Serie Grise (Fischschiefer and equivalents). During the Early Rupelian (Middle Pechelbronn beds), a connection between North Sea and URG is clearly demonstrated, but a general connection between North Sea, URG and Paratethys, via the Alpine sea, is proposed, but not proved, during the late Rupelian. Whereas in the southern URG, a major hiatus spans Early Aquitanian to Pliocene times, Early and Middle Miocene marine, brackish and freshwater facies occur in the northern URG and in the Molasse Basin (OMM, OSM); however, no marine connections between these basins could be demonstrated during this time. After the deposition of the molasse series, a very complex drainage pattern developed during the Late Miocene and Pliocene, with a clear connection to the Bresse Graben during the Piacenzian (Sundgau gravels). During the Late Miocene, Pliocene and Quaternary sedimentation persisted in the northern URG with hardly any interruptions. The present drainage pattern of the Rhine river (from Alpine area to the lower Rhine Embayment) was not established before the Early Pleistocene.     

Stages in the Magura Basin: a case study of the Polish sector (Western Carpathians)

The Magura Basin domain developed in its initial stage as a Jurassic-Early Cretaceous rifted passive margin that faced the eastern parts of the oceanic Alpine Tethys. In the pre- and syn-orogenic evolution of the Magura Basin the following prominent periods can be distinguished: Middle Jurassic-Early Cretaceous syn-rift opening of basins (1) followed by Early Cretaceous post-rift thermal subsidence (2), latest Cretaceous–Paleocene syn-collisional inversion (3), Late Paleocene to Middle Eocene flexural subsidence (4) and Late Eocene - Early Miocene synorogenic closing of the basin (5). The driving forces of tectonic subsidence of the basin were syn-rift and thermal post-rift processes, as well as tectonic loads related to the emplacement of accretionary wedge. This process was initiated at the end of the Paleocene at the Pieniny Klippen Belt (PKB)/Magura Basin boundary and was completed during Late Oligocene in the northern part of the Magura Basin. During Early Miocene the Magura Basin was finally folded, thrusted and uplifted as the Magura Nappe.     

From Tethys to Eastern Paratethys: Oligocene depositional environments, paleoecology and paleobiogeography of the Thrace Basin (NW Turkey)

The Oligocene depositional history of the Thrace Basin documents a unique paleogeographic position at a junction between the Western Tethys and the Eastern Paratethys. As part of the Tethys, shallow marine carbonate platforms prevailed during the Eocene. Subsequently, a three-staged process of isolation started with the Oligocene. During the Early Rupelian, the Thrace Basin was still part of the Western Tethys, indicated by typical Western Tethyan marine assemblages. The isolation from the Tethys during the Early Oligocene is reflected by oolite formation and endemic Eastern Paratethyan faunas of the Solenovian stage. The third phase reflects an increasing continentalisation of the Thrace Basin with widespread coastal swamps during the Late Solenovian. The mollusc assemblages are predominated by mangrove dwelling taxa and the mangrove plant Avicennia is recorded in the pollen spectra. The final continentalisation is indicated by the replacement of the coastal swamps by pure freshwater swamps and fluvial plains during the Late Oligocene (mammal zone MP 26). This paleogeographic affiliation of the Thrace Basin with the Eastern Paratethys after ~32 Ma contrasts all currently used reconstructions which treat the basin as embayment of the Eastern Mediterranean basin.     

Basin formation during the post-collisional evolution of the Eastern Alps: the example of the Lavanttal Basin

The Miocene Lavanttal Basin formed in the Eastern Alps during extrusion of crustal blocks towards the east. In contrast to basins, which formed contemporaneously along the strike-slip faults of the Noric Depression and on top of the moving blocks (Styrian Basin), little is known about the Lavanttal Basin. In this paper geophysical, sedimentological, and structural data are used to study structure and evolution of the Lavanttal Basin. The eastern margin of the 2-km-deep basin is formed by the WNW trending Koralm Fault. The geometry of the gently dipping western basin flank shows that the present-day basin is only a remnant of a former significantly larger basin. Late Early (Karpatian) and early Middle Miocene (Badenian) pull-apart phases initiated basin formation and deposition of thick fluvial (Granitztal Beds), lacustrine, and marine (Mühldorf Fm.) sediments. The Mühldorf Fm. represents the Lower Badenian cycle TB2.4. Another flooding event caused brackish environments in late Middle Miocene (Early Sarmatian) time, whereas freshwater environments existed in Late Sarmatian time. The coal-bearing Sarmatian succession is subdivided into four fourth-order sequences. The number of sequences suggests that the effect of tectonic subsidence was overruled by sea-level fluctuations during Sarmatian time. Increased relief energy caused by Early Pannonian pull-apart activity initiated deposition of thick fluvial sediments. The present-day shape of the basin is a result of young (Plio-/Pleistocene) basin inversion. In contrast to the multi-stage Lavanttal Basin, basins along the Noric Depression show a single-stage history. Similarities between the Lavanttal and Styrian basins exist in Early Badenian and Early Sarmatian times.     

Upper Oligocene VirgulinellaBed of the Ciscaucasus, Volga–Don, and Mangyshlak Regions (Central Part of the Eastern Paratethys)

This work presents the first integral characteristic of the VirgulinellaBed corresponding to the middle part of the Oligocene–Lower Miocene Maikop Group throughout its entire distribution area in the central part of the Eastern Paratethys. It considers lithology, structure, faunal assemblages, and formation settings of carbonate layers with Virgulinellaremains (VirgunellaBed) at the base of the Upper Oligocene clayey sequence that represents the well-expressed marker horizon. It deposited during a brief specific episode in the Oligocene basin development, some features of which remain still unclear.     

The myth of the brackish Sarmatian Sea

The biota of the 1.5 Ma period of the Middle Miocene Sarmatian of the Central Paratethys lack stenohaline components. This was the reason to interpret the Sarmatian stage as transitional between the marine Badenian and the lacustrine Pannonian stages. However, our new data indicate that brackish water conditions could not have prevailed. Sarmatian foraminifera, molluscs, serpulids, bryozoans, dasycladacean and corallinacean algae as well as diatoms clearly indicate normal marine conditions for the entire Sarmatian. During the Lower Sarmatian, however, a sea-level lowstand forced the development of many marginal marine environments. During the Late Sarmatian a highly productive carbonate factory of oolite shoals, mass-occurrences of thick-shelled molluscs and larger foraminifera, as well as marine cements clearly point to normal marine to hypersaline conditions. This trend is not restricted to the western margin of the Pannonian Basin System but can be observed in the entire Central and even Eastern Paratethys.     

Lithostratigraphy and planktonic foraminiferal biostratigraphy of the late Eocene-Middle Miocene sequence in the area between Wadi Al Zeitun and Wadi Al Rahib,Al Bardia area,northeast Libya

The present study deals with the lithostratigraphy and planktonic foraminiferal biostratigraphy of the Late Eocene-Middle Miocene sequence in the Al Bardia area, northeast Libya. The lithostratigraphical studies carried out on three stratigraphical surface sections, namely Wade Al Rahib, Wadi Al Hash and Wadi Al Zeitun, led to the recognition of three rock units from base to top: (1) the Al Khowaymat Formation (Late Eocene-Early Oligocene); (2) the Al Faidiyah Formation (Late Oligocene-Early Miocene); and (3) the Al Jaghboub Formation (Early-Middle Miocene). The planktonic foraminiferal biostratigraphical analysis led also to the recognition of nine planktonic foraminiferal zones ranged in age from Late Eocene to Early Miocene with one larger foraminiferal zone of Middle Miocene age. These are, from base to top, as follows: Truncorotaloides rohri Zone (Late-Middle Eocene, Lutetian), Globigerinatheka semiinvoluta and Turborotalia cerroazulensis s.l. Zones (Late Eocene, Priaborian), Cassigerinella chipolensis/Pseudohasitgerina micra Zone (Early Oligocene, Rupelian), Globigerina ciperoensis ciperoensis, Globorotalia kugleri Zones (Late Oligocene, Chattian), Globigerinoides primordius Zone (Early Miocene, Aquitanian), Globigerinoides altiaperturus/Catapsydrax dissimilis and Globigerinoides trilobus Zones (Early Miocene, Burdigalian), and the larger benthonic foraminiferal zone, Borelis melo melo Zone (Middle Miocene, Langhian to Serravallian). The study of planktonic foraminifera proved the existence of a regional unconformity between the Early and Late Oligocene, with the Middle Oligocene deposits being absent (absence of Globigerina ampliapertura and Globorotalia opima opima Zones), and another, smaller unconformity located between the Late Eocene and Early Oligocene, in which the uppermost part of the Late Eocene is missing.     

阿尔金山脉新生代剥露历史——前陆盆地沉积记录

新疆且末县江尕勒萨依盆地位于阿尔金山脉的北西山前,其内连续沉积了中生代一新生代地层。盆地内古新统一始新统为河流相沉积;渐新统至中新统为山麓河流相灰色砾岩和棕色砂岩;上新统为山麓洪积相砾岩夹泥岩;下更新统全为砾岩层。岩性组合特征及其砂岩碎屑、砾石组分变化规律,反映出阿尔金山脉的新生代剥蚀历史：古近纪早、中期,阿尔金山脉的地形高差小,古生界双峰式火山岩首先被剥蚀;至渐新世末一中新世早期,山脉高差加大,基底元古宇开始出露地表被剥蚀;中新世末期,山脉高差进一步加大,剥蚀速率加快;至第四纪早期西域砾岩开始沉积时,地形高差加剧,中、古元古界开始暴露被剥蚀。区域资料分析表明,阿尔金山脉在新生代具有多期次阶段性隆升的特征,存在3期次快速隆升事件：渐新世末一中新世早期、中新世晚期(大约8Ma)和第四纪早期。     

南海陆缘盆地构造演化与烃源岩特征

受近南北向扩张机制控制,南海陆缘盆地或凹陷多呈NE向带状展布,总体上具有“南三北三”平行排列、外窄内宽的特点。新生代发生的4次重要区域构造运动具有穿时性,共发育3期盆地破裂不整合面,分别是早渐新世与晚渐新世之间、古近纪与新近纪之间、中中新世与晚中新世之间;由东往西,盆地破裂不整合面的时代逐渐变新。受构造运动与海平面升降影响,南海海域发育湖相、海陆过渡相和陆源海相3类烃源岩。由南北两侧向中央海盆,烃源岩类型由湖相逐渐过渡到海陆过渡相与陆源海相;从东向西,盆地主力烃源岩层位逐渐变新,由始新统-渐新统逐渐过渡到渐新统-中新统。南海海域烃源岩的分布规律与盆地破裂不整面存在密切关系:破裂不整合面形成早（早渐新世与晚渐新世之间）的盆地,主力烃源岩形成早（始新统湖相烃源岩）;反之,破裂不整合面形成晚（中中新世与晚中新世之间）的盆地,则烃源岩形成晚（渐新统-中新统海陆过渡相到陆源海相烃源岩）。     

Lower miocene sediments of the Maikop group in the Central Eastern Paratethys

The composite section of upper Maikop sediments compiled for the central part of the Eastern Paratethys is presented. The section (more than 1000 m) comprises the Karadzhalgan, Sakaraulian, and Kotsakhurian regional stages. The lower boundary of the Miocene drawn at the base of the Karadzhalgan regional stage is unambiguous only in the southern part of the central Ciscaucasia. In most areas of the Ciscaucasia, this boundary is drawn arbitrarily because of uniform lithology in the Oligocene-Miocene boundary interval and poor paleontological substantiation. Generally, the Maikop sequence is insufficiently studied and incomplete in many areas because of a discordant upper boundary of the Maikop Group. Nevertheless, materials presented in the paper characterize for the first time the composition and structure of the Lower Miocene sequence over a vast area of the Eastern Paratethys. The horizonwise reconstruction of Early Miocene basins has made it possible to reveal the major features of final stages in the formation of the Maikop clayey sequence.