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新疆塔里木盆地早白垩世克孜勒苏群孢粉组合 总被引:1,自引:1,他引:1
基于新疆塔里木盆地西南区和东南区下白垩统克孜勒苏群发现的孢子花粉57属96种的研究,建立了克孜勒苏群下亚旋回和上亚旋回孢粉组合,并根据孢粉组合讨论了地层时代。克孜勒苏群孢粉组合以松杉目的优势、真蕨目海金沙科的显赫和原始被子植物的出现为特征。克孜勒苏群下亚旋回孢粉组合与欧洲韦尔登期(陆相尼欧克姆期)和北美巴列姆期孢粉组合可以对比,克孜勒苏群上亚旋回孢粉组合与欧亚大陆、北美和澳大利亚阿普第期至阿尔必期孢粉组合可以对比。根据孢粉学证据,克孜勒苏群下亚旋回应属于尼欧克姆期,或赫特里夫期至巴列姆期,克孜勒苏群上亚旋回应归于阿普第期至阿尔必期。 相似文献
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An assemblage of 17 identified and four unknown pollen and sporetypes is reported from the Pliocene Rio Banano Formation of southeasternCosta Rica. The most abundant are monolete fern spores, Palmae, cf.Antrophyum, Symphonia, Pelliceria,Lacmella (previously unreported in the fossil record),Alchornea, and Sabicea. These arrange into twopaleocommunities-mangroves and lowland tropical rain forest. Annual precipitation is estimated at near the present ~3500 mm, butless seasonal, and the MAT (mean annual temperature) at ~27°C. No pollen taxa representing distinctly arid or high-altitude vegetationwas being blown or washed into the coastal depositional basin, and nopollen grains were recovered of northern temperate elements that arepresent in Neogene floras to the north in Guatemala and southeasternMexico. These data are consistent with those from 12 other Miocene andPliocene palynofloras from northern Latin America, indicating the lateappearance of dry habitats and moderate paleoelevations and aprogressive southward introduction of northern temperate elements withlate Cenozoic cooling. 相似文献
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Systematic palynological research was conducted on more than 343 samples from a column or rock core obtained by drilling to a depth of 20 m in Gucheng lake. According to three assemblage zones and nine subzones of the sporo-pollen, and the dating of 14℃, we have explored the regularity of palaeoclimatic changes and palaeomonsoon activities since 15.0 ka BP. During 15.0 ~ 11.0 ka BP, the temperature had increased a little, but the climate was still cool and relatively dry, reflecting a weak wet monsoon and low precipitation at that time. In the period of 3~11.0 ka BP, it became cold and wet, with an increased effect of the dry monsoon, and the area was probably situated in a position of the frontal zone. Causing considerable effective humidity. Later than 11.0 ka BP, the temperature increased rapidly within 500 years with a subsquent, turn of the climate towards significantly warmer and wet and a further intensification of the monsoon effect. This rapid temperature increase corre-sponded to the increasing radiation of solar energy during 11.0~10.0 ka BP. From 10.5 to 6.4 ka BP, the wet monsoon was the priority climate of the region, albeit there were at least two or three spells of cooling, as well as decreasing of monsoon precipitation. 相似文献
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黑龙江省东部鸡西盆地早白垩世滴道组的沟鞭藻类 总被引:9,自引:0,他引:9
首次描述鸡西盆地滴道组的沟鞭藻化石2新种:Lagenorhytis granorugosus sp.nov.和Vesperopsis di-daoensis so.nov.;讲座沟鞭藻组合特征,地质时代及沉积环境;认为滴道组含沟鞭藻化石的层 的时代为早白垩世早期,很可能为Berriasian-Valanginian期。沟鞭藻化石证实,在早白垩世早期滴道组沉积时,鸡西盆地曾遭受短暂的弱的海水影响。 相似文献
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内蒙古二连盆地早白垩世巴彦花群被子植物花粉 总被引:2,自引:1,他引:2
内蒙古二连盆地早白垩世巴彦花群含有类型丰富、保存精美的被子植物花粉。本文利用光学显微镜观察和扫描电镜观察相结合的方法,对这些花粉类型进行了较详细的研究。研究结果表明,巴彦花群的被子植物花粉主要由属于金粟兰科的Hammenia和Singhipollis,悬铃木科/金缕梅科的Tricolpites以及亲缘关系不明的Polyporites组成。这一被子植物花粉组合面貌指示的地质时代为中晚阿尔必期(Albian)。据相关现生植物的地理分布及煤夹层的存在,推测在早白垩世晚期二连盆地处于湿润的亚热带气候环境中。 相似文献
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江苏固城湖区一万多年来的孢粉植物群及古季风气候变迁 总被引:15,自引:0,他引:15
通过对固城湖 2 0 m岩芯钻孔 34 3块样品进行孢粉分析 ,划分出 3个孢粉组合带及 1 0个组合亚带。结合 14 C测年着重讨论了该区 1 5 .0 ka BP以来古气候变迁及古季风活动规律。研究表明 ,1 5 .0~ 1 1 .0ka BP虽然气温已回升 ,但总的说来气候仍偏冷凉 ,降水不丰富 ,变化较频繁 ,反映当时夏季风较弱 ,季风降水较少。其中 1 1 .3~ 1 1 .0 ka BP的冷湿期反映冬季风效应增强 ,该区可能位于锋面进退的位置 ,造成较大的有效湿度。约 1 1 .0 ka BP以后短短 5 0 0年内 ,气温迅速上升 ,此后气候明显转暖变湿 ,夏季风效应进一步增强。这种快速增温 ,与 1 1 .0~ 1 0 .0 ka BP太阳辐射能的增加相对应。 1 0 .5~ 6.4 ka BP,该区以较强的夏季风为主要特点 ,但仍存在 2~ 3次降温波动 ,季风降水有所减少 相似文献
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陕西彬县地区中侏罗世延安组孢粉植物群及其意义 总被引:7,自引:0,他引:7
报道了采自陕西彬县地区中侏罗世延安组的孢粉化石60属,83种。经研究表明,陕西彬县地区延安组的孢粉组合是以裸子植物花粉为主,蕨类植物孢子次之。银杏、苏铁类和松柏类花粉在组合中占优势;桫椤科孢子在蕨类中具有较高的含量。根据孢粉组合特征及其对比,延安组的时代应属中侏罗世早期。陕西彬县地区当时的植被是以银杏、苏铁类和松柏类等乔木为主,并伴有桫椤科为主体的树蕨植物及草本植物,古气候应属大陆性亚热带气候。 相似文献
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Botanical data are widely used as terrestrial proxy data for climate reconstructions. Using a newly established method based on probability density functions (pdf-method), the temperature development throughout the last interglacial, the Eemian, is reconstructed for the two German sites Bispingen and Gröbern and the French site La Grande Pile. The results are compared with previous reconstructions using other methods. After a steep increase in January as well as July temperatures in the early phase of the interglacial, the reconstructed most probable climate appears to be slightly warmer than today. While the temperature is reconstructed as relatively stable throughout the Eemian, a certain tendency towards cooler January temperatures is evident. January temperatures decreased from approx. 2–3 °C in the early part to approx. –3 °C in the later part at Bispingen, and from approx. 2 °C to approx. –1 °C at Gröbern and La Grande Pile. A major drop to about –8 °C marks the very end of the interglacial at all three sites. While these results agree well with other proxy data and former reconstructions based on the indicator species method, the results differ significantly from reconstructions based on the modern pollen analogue technique (pollen transfer functions). The lack of modern analogues is assumed to be the main reason for the discrepancies. It is concluded that any reconstruction method needs to be evaluated carefully in this respect if used for periods lacking modern analogous plant communities. 相似文献
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This paper presents eight ephedroid palynomorphs from the Lower Cretaceous (Upper Albian) of Hokkaido, Japan. The ephedroid palynomorphs are ellipsoid and polyplicate pollen grains that show a wide range of variation in pollen size, shape, and plication. These ephedroid palynomorphs suggest a wide range of diversity in Gnetales at mid- or high-paleolatitude in the eastern side of Lauresia during the Upper Albian. 相似文献
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JAIME ORTEGA‐BLANCO ENRIQUE PEÑALVER XAVIER DELCLÒS MICHAEL S. ENGEL 《Palaeontology》2011,54(3):511-523
Abstract: The fauna of false fairy wasps (Proctotrupomorpha: Bipetiolarida: Mymarommatoidea) occurring in Early Cretaceous (Albian) amber from north and north‐eastern Spain (Moraza, San Just, and El Soplao outcrops) is described. In total, 12 specimens have been recovered and four species recognized, all new: Alavaromma orchamum gen. nov. and sp. nov. (Alavarommatidae fam. nov.), Archaeromma hispanicum sp. nov. (Mymarommatidae), Galloromma alavaensis sp. nov., and G. turolensis sp. nov. (Gallorommatidae). The study indicates the necessity of revision and maybe fusion of both superfamilies, Mymarommatoidea and Serphitoidea, as the boundaries between them are less and less defined. However, major classificatory rearrangements must await the completion of the cladistic studies presently underway. 相似文献
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The successive vegetations inhabiting the Iberian Peninsula from the Triassic/Jurassic boundary to the Cretaceous/Tertiary Boundary is reviewed based on published palynological and macrofloral data, and the vegetational changes set in a palaeogeographical and climate context. Xerophytic microphyllous coniferous forests and pteridophyte communities of arid environments dominated the Jurassic and earliest Cretaceous vegetation. This vegetation was replaced in the mid Early Cretaceous by mixed forests of pteridophytes, gymnosperms and angiosperms. The composition of the successive plant assemblages suggests that a subtropical arid climate generally prevailed in the Iberian Peninsula during Jurassic-Cretaceous, although palaeobotanical and sedimentological evidences suggest that the climate was not uniform through the whole interval and that were two episodes in the Tithonian-Berriasian and Aptian-Albian periods of pronounced dry and/or arid environmental conditions. The composition and structure of the vegetation was not only affected by evolutionary changes but also by successive global geographical and climate changes. Hence, significant changes in the distribution of continental areas during the Mesozoic resulted in the latitudinal or sublatitudinal extensions of the climatic belts. 相似文献
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Frank Neumann Christian Schölzel Thomas Litt Andreas Hense Mordechai Stein 《Vegetation History and Archaeobotany》2007,16(4):347-346
In this paper we present and discuss palynological results based on a composite profile from Birkat Ram crater lake (Northern Golan, Near East) in order to reconstruct the environmental history, including human impact, of the last 6500 years. Furthermore we apply a newly-developed botanical climatological transfer function to reconstruct climate variations in the northern Golan Heights based on this pollen data-set. The Birkat Ram record is strongly influenced by anthropogenic indicators in the pollen diagram with high quantities during the Chalcolithic period/Early Bronze Age, during the Hellenistic-Roman-Byzantine periods, during the Crusader period and finally during modern times. The palaeoclimate reconstruction method used is based on a Bayesian approach and is robust in avoiding the influence of these strong anthropogenic signals on the reconstruction results. The area has always had Mediterranean climate conditions and no distinctive climate changes can be identified during the past 6500 years. Because of the orography of the Mt. Hermon region the particular geographical position of the northern Golan Heights is obviously capable of buffering large-scale fluctuations in precipitation, which have otherwise been documented for several regions in the Near East. Electronic Supplementary Material Supplementary material is available for this article at An erratum to this article can be found at 相似文献
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An assemblage of 46 fossil pollen and spore types is described from a core drilled through the middle Eocene Saramaguacán Formation, Camagüey Province, eastern Cuba. Many of the specimens represent unidentified or extinct taxa but several can be identified to family (Palmae, Bombacaceae, Gramineae, Moraceae, Myrtaceae) and some to genus (Pteris, Crudia, Lymingtonia?). The paleoclimate was warm-temperate to subtropical which is consistent with other floras in the region of comparable age and with the global paleotemperature curve. Older plate tectonic models show a variety of locations for proto-Cuba during Late Cretaceous and later times, including along the norther coast of South America. More recent models depict western and central Cuba as two separate parts until the Eocene, and eastern Cuba (joined to northern Hispaniola) docking to central Cuba also in the Eocene. All fragments are part of the North American Plate and none were directly connected with northern South America in late Mesozoic or Cenozoic time. The Saramaguacán flora supports this model because the assemblage is distinctly North American in affinities, with only one type (Retimonocolpites type 1) found elsewhere only in South America. 相似文献
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Uxue Villanueva-Amadoz Luis Miguel Sender Luis Alcalá Denise Pons Rafael Royo-Torres José B. Diez 《Historical Biology》2015,27(3-4):430-441
The AR-1 layer, corresponding to the Escucha Formation (Lower Cretaceous) in the Santa Maria Mine of Ariño, has supplied rich and well-preserved macrofloral and palynological assemblages showing interesting data about both taphonomic and environmental conditions. This single layer is located in the Oliete Sub-Basin from the Maestrazgo Basin in northeastern Spain, and it represents one of the most outstanding single layer fossil sites in the world. This site shows abundant and diverse fauna containing exquisitely preserved vertebrate and invertebrate fossils (dinosaur bones, turtles, crocodiles, fishes, molluscs and ostracods) and also plant remains of Albian age. The assemblage is especially significant for dinosaur phylogenetic analysis. The sedimentary environment corresponds to a freshwater swamp plain with sporadic marine inputs within a deltaic–estuarine system under subtropical–tropical climate. 相似文献
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R. M. Joeckel J. M. Cunningham R. G. Corner G. W. Brown P. L. Phillips G. A. Ludvigson 《Ichnos》2013,20(3-4):275-284
At least 22 tridactyl dinosaur tracks, poorly preserved in various degrees of expression, have recently been found at an exposure in the Dakota Formation (Lower Cretaceous, Albian) in Jefferson County, Nebraska. These tracks generally have broad, blunt digits and a broad posterior margin. The largest of the tracks measures 57 cm in length and 58 cm in width. All of the tracks lie within a stratigraphic horizon of 40 cm or less, but they do not form a single trackway. We interpret the trackmakers to have been ornithopods. The Jefferson County tracks are in a well-cemented sandstone with oscillation ripples, at a stratigraphic level between two well-established sequence boundaries. Channel forms and lateral accretion units are common in the stratigraphic interval enclosing the tracks, and the site is interpreted as a bar or sand flat in a tidally influenced river. The Jefferson County tracks are only the second known occurrence of large Mesozoic tetrapod tracks east of the Rocky Mountain Front-High Plains Margin, including the Black Hills of South Dakota, west of the Atlantic Coastal Plain, and north of the Gulf Coastal Plain. Further, this paper is the first documentation of in situdinosaur fossils from the Nebraska-Iowa area. 相似文献