Petroleum Sporo-Pollen Assemblage and Oil Source Rock of Yecheng Seg in Xinjiang

Forty-seven species of fossil pollens and spores referred to 33 genera extracted from the crude oil samples collected from the Yecheng Seg of the Talimu Basin in Xinjiang were observed. Based on the investigation of the characteristics of the petroleum sporo-pollen assemblage, the problem on petroleum source of this oil-bearing region is discussed. The principle and method to judge source rock from petroleum sporo-pollen assemblage are specially explained in this paper. The petroleum sporo-pollen assemblage of the Neogene reservoir of the Yecheng Seg consists of Deltoidospora perpusila, Deltoidospora gradata, Cyathidites australis, Cyathidites minor, Biretisporites potoniaei, Dictyophyllidites harrisii, Dictyophyllum rugosum, Cibotiumspora paradoxa, Gleicheniidites senonicus, Gleicheniidites rousei, Undula- tisporites concave, Lycopodiumsporites sp., Osmundacidites wellmanii, Leptolepidites major, Apiculatisporis ovalis, Bennettiteaepollenites lucifer, Cycadopites typicus, Cyeadopites nitidus, Cycadopites minimus, Cycadopites carpentieri, Cycadopites follicularis, Chasmatosporites elegans, Classopollis classoides, Classopollis annulatus, Podocarpidites multesimus, Podocarpidites major, Parvisaccites enigmatus, Quadraeeulina limbata, Caytonipollenites pallidus, PteruchipoUenites thomasii, Alisporites grandis, Alisporites bilateralis, AbietineaepoUenites microalatus, Abietineaepollenites minimus, Pinuspollenites sp., Piceaepollenites sp., Cedripites st)., Ephedripites sp., Eucommiidites troedssonii, Magnolipollis neogenicus, Quercoidites microhenrici, Chenopodipollis multiplex, Artemisiae-pollenites sellularis, etc . This is a typical composite type of petroleum sporo-pollen assemblage, which eomprises the Jurassic species, the Cretaceous species, the Eogene species and the Neogene species of spores an, d pollen. In accordance with the characteristics of the above mentioned petroleum sporopollen assemblage, the source rock of the Yecheng Seg is considered to be Jurassic Period in age, and the black shales and mudstones of the Middle Jurassic Yangye-Taerga Formation are judged to be the most favorable source rocks in the region.     

Petroleum Sporo-Pollen Assemblages and Oil Source Rock of Yumen Oil bearing Region in Gansu

Twenty-six species (or forms) of fossil pollen and spores referred to 24 genera extracted from the crude oil samples collected from the Yumen oil-bearing region in West Gansu are observed and the definition of the petroleum sporo-pollen assemblage is given by the authors. On the basis of palynological investigation, the oil source rock of this oil-bearing region is tentatively discussed in this paper. The fossil pollen and spores found from the Tertiary petroleum in this region may be divided into two groups, because they are extremely different in fossilized state. The group of spores and pollen with higher fossilized state is mainly consisted of Schizaeoisporites zizyphinus, Gibotiumspora paradoxa, Monosulcites minimus and Bennettiteaepollenites sp. The other group comprises Pinus, Picea, Ephedra, Potamogeton, Lilium, Ulmus, Chenopodium, Nymphaea, Eutrema, Lens, Nitraria, Tamarix, Achillea, Artemisia, Solidago, Bidens, Graminidites, Cypheraceaepollis, etc. The above mentioned petroleum sporo-pollen assemblage of the tertiary oil reservoir rock is a gathering of fossil pollen and spores brought from the Lower Cretaceous deposits and the tertiary deposits respectively. The appearance of the Early Cretaceous pollen and spores bearing in the black shales of the Lower Xinminbu Formation in the tertiary petroleum may be considered to be a result of petroleum migration. And it reflects that the oil source rock might belong to Early Cretaceous Series. The fossil pollen and spores extracted from the Early Cretaceous petroleum in this region contain merely Schizaeoisporites zizyphinus, Monosulcites minimus, Bennettiteaepollenites sp., Psophosphaera, etc. The tertiary pollen and spores are completely absent there. So it indicates that both the oil source rock and the oil reservoir rock should belong to the fossil-bearing Lower Xinminbu Formation. In addition, there are some pollen of Monosulcites and Psophosphaera in the petroleum reserved in the fissures of the Silurian metamorphic rock. They are also probably brought from the Lower Xinminbu Formation by oil and gas in the process of their migration. In any case, judging from the pollen and spores found from the crude oil, the oil source rock of this oil-bearing region is deduced to be the black shales of the Lower Xinminbu Formation referred to as Early Cretaceous Epoch.     

Early Cretaceous Palynofloras from Tarim Basin,Xinjiang

One hundred and eight species of fossil spores and pollen referred to 55 genera found from the Lower Cretaceous Kapushaliang (Kizilsu) Group in the Tarim Basin of Xinjiang have been studied in this paper. The Kapushaliang Group may be divided into the Yageliemu Formation, the Shushanhe Formation and Baxigai Formation in ascending order. The Yageliemu palynoflora is characterized by the predominance of gymnospermous pollen, the relative abundance of pteridophytic spores and the absence of angiospermous pollen. Coniferae is dominant, while Lygodiaceae and Schizaeaceae are important in the flora. The most common species of palynomorphs are Todisporites minor, Cicatricosisporites dorogensis, C. australiensis, Lygodiumsporites subsimplex, Schizaeoisporites cretacius, S. zizyphinus, S. certus. Cibotiumspora paradoxa, Cyathidites australis, C. minor, Biretisporites potoniael, Cycadopites minimus, Pseudowalchia hiangulina, Parvisaccites radiatus, Podocarpidites multesimus, P. canadensis, Alisporites bilateralis, Cedripites cretaceus, C. canadenris, Abietineaepollenites microalatus, Clarsopollis classoides, C annulatus, C. xinjiangensis (sp. nov.), Ephedripites multicostatus, E. tarimensis (sp. nov.), etc . The palynoflora is comparable with those of the lower part of the Lower Xinminbu Formation in northwestern China and the lower part of the Lower Mannville Formation in western Canada, which is considered corresponding from Berriasian to Valanginian in age. The Shushanhe palynoflora is also characterized by dominance of gymnosperms and subdominance of pteridophyta. Some primitive angiospermons pollen grains are found in the upper part of the formation. In addition to the most common species of the above mentioned palynoflora, the important species in the present palynoflora comprise Cicatricosisporites potomacensis, C. orbiculatus, C. subrotundus, Concavissimisporites punctatus, C. verrucosus, C. globosus, lmpardecispora apiverrucata, Trilobosporites crassus, T. trioreticulosus, Pilosisporites verus, P. trichopapillosus, Klukisporites pseudoreticulatus, Verrucosisporites obscurilaesuratur, Converrucosisporites saskatchewanensis, Foraminisporis wonthaggiensis, Cingulatisporites valdensis, C. ruginosus, Jiaohepollis verus, Pityosporites constrictus, etc. More than 40 in dicative species of Early Cretaceous occur in the assemblage. The palynoflora compares clcsely with those of the middle part of the Lower Xinminbu Formation and the Quartz Sand Member of the Lower Mannville Formatton. It is suggested that the Shushanhe Formation should belong to Hauterivian of Barremian in age. The Baxigai palynoflora is basically similar to the Shushanhe palynoflora. But the palynoflora shows an obvious increase in abundance of lygodiaceous spores and angiospermous pollen accompanied by a great reduction of Classopollis and Ephedripltes. Most of the Early Cretaceous species occurring in the above mentioned palynofloras are present. In addition, some Cretaceous species recorded from Aptian and Albian Stages in Europe, North America and Australia, such as Trilobosporites tribotrys, T. trioreticulosus, Coptospora paradoxa, Camarozonosporites insignis, Crybelosporites punctatus, etc., appear in the assemblage. In comparison with the microfloras of the upper part of the Lower Xinminbu Formation, the Upper Mannville Formation and the lower part of the Lower Colorado Group, the Baxigai Forma- tion should be referred to Aptian to Albian in age. Judging from the palynofloras, the early Cretaceous palaeoclimate in the basin should belong to the arid or semi-arid type of the subtropic zone. However, from Barremtan through Albian the climatic conditions might appear relatively wet.     

Pollen and Spores Extracted from Petroleum of Liaohe oil-Field and Their Significance

Twenty-nine species (or forms) of fossil pollen and spores referred to 23 genera extracted from the petroleum samples taken from the Liaohe oil-field are investigated in this paper. Using the above plant microfossils as indicators, the oil source rock of this oil-field are traced. The spores and pollen extracted from the petroleum reserved in the Shahejie Fomation of the Liaohe oil-field are as follows: Pterisisporites undulatus, Osmundacidites wcllmanii, Plicifera decora, Pinuspollenites labdacus f. minor, Abietineaepolle- nites cembraeformis, A. microsibiricus, Cedripites diversus, Keteleeria dubia, Ephcd- ripites cheganicus, Graminidites sp., Liliacidites sp., Quercoiditcs asper, Retitricolporites sp., Chenopodipollis microporatus, Compositoipollenites sp, etc. The following spores and pollen are extracted from the crude oil reserved in the Dongying Formation of the present oil-field: Osmundacidites wellmanii, Plicifera decora, Pinuspollenites labdacus f. minor, Sparganiaccaepollenites sp., Graminidites sp., Liliacidites sp., Chenopodipollis multiporatus, Compositoipollenites sp., Artemisiaepol- lenites sp., etc. Some Fossil Fungi and Algae are observed from the above mentioned petroleum samples. Comparing the spores and pollen extracted from the petroleum of the Shahejie Formation with those of the sporo-pollen complex of the Shahejie Formation, it may be decided that they all came from the deposits of the Shahejie Formation. This character indicates that the oil source rock should coincide with the oil reservoir rock, and both of them belong to the Shahejie Formation which is referred to Early Tertiary Period. By comparison with the sporo-pollen complexes of the Dongying Formation and the Shahejie Formation, most of the pollen and spores found from the petroleum of the Dongying Formation may be found to come from the Dongying Formation, and the rest of them from the underlying Shahejie Formation. Thus it implies that the petroleum reserved in the Dongying Formation should also originate from the Shahejie Formation.     

Spores and Pollens from Crude Oil of Turpan Basin,Xinjiang

Sixty-eight species of fossil spores and pollens referred to 39 genera extracted from the crude oil samples collected from the Turpan Basin of Xinjiang are recorded in this paper. Based on the investigations of fossil spores and pollens in petroleum, the questions on petroleum migration and source rocks are discussed. It is expounded and proved theoretically and practically that the phenomenon that the crude oil samples usually contain the fossil spores and pollen grains with different geological ages from reservoir rocks should result from petroleum migration, but not from resedimentation. The fossil spores and pollens in crude oil of the Middle Jurassic reservoir of the Qiktim Oil-Field of the Turpan Basin comprise mainly Leiotriletes pflugi, Deltoidospora gradata, D. magna, Cyathidites australir, C. minor, Biretisporites cf. potoniaei, Dictyophyllidites harrisii. Cibotiumspora paradoxa, C. jurienensis, Gleicheniidites rousei, G. conflexus, Undulatisporites concavus, U. pflugii, Granulatisporites arenaster, G. minor, Todisporites minor, Osmundacidites wellmanii, dpiculatisporis variabilis, Leptolepidites major, Aratrisporites scabratus Cycadopites nitidus, C. typicus, C. subgranulosus, Chasmatosporites elegans, Classopollis classoides, C. itunen- sis, C. annulatus, C. qiyangensis, Callialarporites dampieri, C. radius, lnaperturopollenites det- tmannii, Protoconiferus funarius, Paleoconiferus asaccatus, CaytonipoUenites pallidus, Vitreis- porites jurassicus, V. jansonii, Pseudowalchia ovalis, P. landesii, P. biangulina, Podocarpidites unicus, P. major, P. multicinus, P. multesimus, P. rousei, P. wapellaensis, Platysaccus lopsinensis, Ovalipollis enigmatica, O. minor, O. canadensis, Pteruchipollenites thomasii, Alisporites grandis, A. bilateralis, Pityosporites similis, P. divulgatus, Piceites expos us, P. podocarpoides, P. latens, Protopicea exilioides, Pseudopicea variabitifornus, Piceaepollenites complanatiformus, Abietineaepollenites dunrobinensis, A. microalatus, A. minimus, Cedripites minor, Eucommiidites troedssonii, etc. Some of the species are also found from the crude oil sampls taken from the Middle Jurassic reservoir of the Shengjinkou Oil-Field of the Turpan Basin. The above mentioned species of spores and pollens are widely distributed in the Lower to Middle Jurassic sediments of North America, Europe, Australia and China. They have also been found from the Lower to Middle Jurassic sediments of the Turpan Basin. Judging from the spores and pollen in petroleum, it may be concluded that the Lower Jurassic Badaowan-Sangonhe Formation and the Middle Jurassic Xishanyao-Toudenhe Formation should contain the favorable petroleum source rocks in the basin. As to petroleum migration mechanism, it is considered that petroleum must have migrated for comparatively short distances to accumulate into petroleum pools in this region.     

新疆喀什凹陷原油中的孢子花粉

记述了新疆塔里木盆地喀什凹陷原油中萃取出的孢子花粉化石 30属 46种 .基于原油中孢粉化石的研究 ,追朔了该含油区的油源 ,并探讨了石油运移机理 .根据原油孢粉集合的特征 ,下侏罗统康苏组和中侏罗统杨叶组及塔尔尕组应是本区的油源岩系 .原油中来自油源岩系孢粉化石的发现 ,说明微裂隙是石油初次运移的通道 ,裂隙、节理、断层、不整合面等是石油二次运移的通道     

Spores and Pollen from Crude Oil of Kashi Depression,Xinjiang

Forty-six species of fossil spores and pollen referred to 30 genera extracted from the crude oil samples collected from the Kashi Depression of the Tarim Basin in Xinjiang were recorded . Based on the investigations of the palynomorphs in crude oil. the petroleum source of the petroliferous region was traced and the petroleum migration mechanism is discussed. The fossil spores and pollen found from crude oil of the Neogene reservoir of the Kelatuo Oilfield of the Kashi Depression comprised mainly Deltoidospora lineata, Cyathidites australis, C. minor, Gleicheniidites rousei, Dictyophyllidites harrisii, Cibothtmspora paradoxa, Todisporites major, Granulatisporites minor, Leptolepidites major, Klukisporites variegatus, Murospora jurassica, M. minor, Paleoconiferus asaccatus, Vi!reisporites jurassicus, V. shouldicei, V. jansonii, Alisporites thomasii, A. lowoodensis, Podocarpidites florinii, P. langii, P. multicinus, P. multesimus. Quadraeculina limbata, Protopinus scanicus. Protopicea exiliolides, Piceites expositus. P. latens, Pinuspollenites labdacus. Piceaepollenites alatus, Cedripites minor, Chasmatosporites major, C. elegans, C. canadensis, Cycadopites nitidus, C. typicus, Ephedripites tertiarius, CerebropoUenites carlylensis, Classopollis classoides, C. annulatus, Caryapollenites simplex, Chenopodipollis multiplex, Artemisiaepollenes sellularis, etc. According to the characteristics of the petroleum sporo-pollen assemblage, the Lower Jurassic Kangsu Formation and the Middle Jurassic Yangye and Taerga Formations should be the petroleum source rock series of the Kashi Depression. Judging from the palynomorphs of the source rocks found in crude oil. It might be concluded that the fossil spores and pollen together with oil beads must have been expelled from the source rocks along microfissure avenuses during the primary migration along fissures, joints faults, and unconformity planes during the secondary migration.     

Early Cretaceous Palynoflora from Anchow Basin,Korea

Fifty-nine species of fossil spores and pollen referred to 34 genera found from the Lower Cretaceous Longpan Formation in Anehow Basin of North Korea have been studied. Two species were described as new. The palynoflora of the Longpan Formation was characterized by its predominance of gymnosperms and subdominance of pteridophyta. A few primitive angiospermous pollen grains occured in the middle to upper part of the formation. Coniferae was dominant in the whole palynoflora, while Lygodiaceae and Schizaeaceae were dominant in the pteridophyta. The important species of spores and pollen comprised Cicatricosisporites dorogensis, C. subrotundus, L ygodioisporites gemmatus, Concavissimisporites asper, C. variverrucatus, C. penolaensis, Trilobosporites minor, Klukisporites variegatus, K. pseudoreticulatus, K. scaberis, Sch, izaeoisporites cretacius, S. certus, S. zizyphinus, S. gansuensis, Foraminisporis wonthaggiensis, Converrucosisporites saskatchewanensis, Densoisporites microrugulatus, Parvisaccites radiatus, Platysaccus oculus, P. gansuensis, Podocarpidites canadensis, AbietineaepoUenites minimus, Pinuspollenites insignis, Cedripites cretaceus, C. canadensis, Classopollis classoides, C. annulatus, C. minor, C. anchowensis, Cycadopites minimus, Ephedripites tarimensis, and Clavatipollenites hughesii. The palynoflora is comparable with that of the Changcai Formation of the Yanbian District of the Jilin Province of China. It is suggested that the Longpan Formation of North Korea should belong to Barremian to Aptian in age. Judging from the palynoflora, the Early Cretaceous palaeoclimate in the Anchow Basin should belong to the semi-arid type of the subtropic zone.     

朝鲜安州盆地早白垩世孢粉组合

报道朝鲜安州盆地下白垩统龙盘组孢子花粉３４ 属５９ 种（包括２ 新种）,并根据孢粉组合讨论了地质时代和古气候特征。龙盘组孢粉组合以裸子植物花粉为主,蕨类植物孢子次之,出现少许原始被子植物花粉。松柏纲花粉在组合中占绝对优势;海金沙科和莎草蕨科孢子则在蕨类中占优势。根据孢粉组合,龙盘组的时代应属早白垩世巴列姆期至阿普第期;安州盆地当时气候温暖偏干,属亚热带半干旱型     

内蒙古开鲁盆地早白垩世阜新组孢粉组合

开鲁盆地陆家堡坳陷白垩系十分发育,富含各门类生物化石。根据坳陷内钻井所采样品,系统研究了早白垩世阜新组孢粉化石,建立以Cicatricosisporites Laevigatosporites Tricolpopollenites 为代表的孢粉组合。根据典型分子时代分布及横向组合对比,确定其地质时代为巴列姆—阿普第期,孢粉植物群反映的气候特征为潮湿的亚热带。     

新疆独山子油田原油中的孢子花粉

本文研究了新疆准噶尔盆地独山子油田原油中分离出的孢子花粉35属51种。基于原油中孢子花粉的研究,追溯了该含油区的油源并讨论了油气运移问题。根据原油中找到的孢子花粉化石来判断,准噶尔盆地西南含油区有两套油源岩系,即下一中侏罗统八道湾一头屯河组和渐新统安集海河组。     

新疆吐哈盆地北缘黄山街组孢粉组合

新疆鄯照壁山沟口和柯柯亚剖面黄山街组的孢粉化石,经研究,共有52属77种。命名为Dictyophylli-dites-Aratrisporites-Parataeniaesporites组合（简称DAP组合）。根据组合主要分子的已知时代分布、含量高低变化,以及与有关已知时代孢粉组合进行对比,鉴定其地质时代为晚三叠世早中期。根据孢粉组合恢复古植被,反映当时的气候为温暖潮湿的温带类型。     

Early and Middle Jurassic Sporo-Pollen Assemblages of Qiquanhu Coal-Field of Turpan Xinjiang

One hundred and thirteen species of spores and pollens belonging to 58 genera were found from 66 core samples taken from two boreholes of the Early and Middle Jurassic deposits in the Qiquanhu coal-field of the Turpan Basin, Xinjiang have been investigated in this paper. Two of the species are described as new. Three sporo-pollen zones from lower to upper are described as follows: Sporo-pollen zone Ⅰ (equivalent bed: Badaowan Formation) . The pteridophytic spores are slightly more abundant than the gymnospermous pollen in this assemblage. The most abundant spores are Cyathidites minor, C. australis and Undulatisporites pflugii, U. taenus and so on. The second important fern spores are Osmundacidites, Lycopodiumsporites, Apiculatisporis and Duplexisporites. The most important gymnospermous genus is Cycadopites which ranks highest in the assemblage and includes C. nitidus and C. typicus.The other gymnospermous pollen include Classopollis, Pinuspollenites, Protoconiferus Piceites. Besides, there are a few pollen grains of Taeniaesporites and Chordasporites surviving from the Late Triassic in this assemblage. The present assemblage may be compared with the Early Jurassic sporopollen assemblage from the Daling Formation of the North-East Guangxi. Therefore, the Badaowan Formtion may be referred to Early Jurassic in age, probably Early Lias. Sporo-pollen zone Ⅱ (equivalent bed: Sangonghe Formation) In this assemblage the gymnosperms are predominant.Of them, Podocarpidites and Pinuspollenites increase obviously, and Quadraeculina and Protoconiferus are common. Few surviving elements are observed. The most abundant spores are those of Cyathidites, and the particularly abundant pollens are those of Cycadopites, This assemblage may be compared with the Late Lias sporo-pollen assemblage from the Fuxian Formation of the Northern Shangganning Basin. Therefore, the Sangonghe Formation should belong to Early Jurassic, probably Late Lias in age. Sporo-pollen zone Ⅲ (equivalent bed: Xishanyao Formation). The contents of the spores and pollens are almost equal in this assemblage. Cyathidites and Cycadopites are the most important spores and pollen. Osmundacidites and Quadraeculina are common. Neoraistrickia, Lycopodiumsporites and Eucommiidites troedssonii are present. Ancient striate bisaccate pollen disappears. The characteristics of this assemblage show some resemblances to those of the Middle Jurassic Yanan Formation in Chongxin county of Gansu province. So the Xishanyao Formation should belong to Middle Jurassic.     

新疆鄯善照壁山克拉玛依组孢粉组合

本文研究了新疆鄯善照壁山沟口克拉玛依组顶部的孢粉化石,共鉴定孢粉４６属７０种,命名为Ｐｕｎｃｔａｔｉｓｐｏｒｉｔｅｓ－Ａｒａｔｒｉｓｐｏｒｉｔｅｓ－Ｔａｅｎｉａｅｓｐｏｒｉｔｅｓ－Ｐａｒａｔａｅｎｉａｅｓｐｏｒｉｔｅｓ组合。根据组合主要分子的时限及其含量变化,以及与有关已知时代孢粉组合进行对比,鉴定其其他质时代为中三叠世。根据孢粉植物群反映当时为温湿的气候特征。     

辽河盆地大民屯凹陷沈249井早白垩世九佛堂组孢粉组合

沈249井九佛堂组孢粉材料是目前所知辽河盆地孢粉类型最丰富、数量最多且保存最完好,可确定63属,包括蕨类植物孢子40属和裸子植物花粉23属;根据孢粉组合特征,可称其为Cicatricosisporites Concavissimi sporites Classopollis孢粉组合,具有裸子植物花粉相对含量明显较高、分异性较低,而蕨类植物孢子分异性明显较高、相对含量较低的特点;该组合与辽西九佛堂组、内蒙古二连盆地赛汉塔拉组一段的孢粉组合具有很强的一致性。本文资料可弥补辽河盆地九佛堂组孢粉组合的空白,并为深入认识我国北方区九佛堂组沉积时期植物群特征提供重要的帮助。     

鄂尔多斯盆地晚石炭世孢粉组合

本文报道了鄂尔多斯盆地晚石炭世太原组的孢粉组合,共计68属,148种(类型)。本文描述了其中的9个新种,2个新组合和4个未定种,并建立一个组合带,即 Pseudolyosporaradialis-Gulisporites discersus-Thymospora thiessenit。根据孢粉组合情况,可看出盆地东部更接近于华北,西部则发生区系上的变化。整个孢粉组合可与盆地北缘、华北地区的太原组以及欧美等地区的维斯法期 C-D 和斯蒂芬期的孢粉组合比较。地质时代当属晚石炭世。     

柴达木盆地侏罗系油源的孢粉学证据

记述了青海柴达木盆地侏罗系油储原油中萃取出的孢子花粉化石27属45种。基于原油中孢粉化石的研究及其与潜在油源岩中孢粉化石的对比,确定了含油区的油源岩。并根据孢子花粉母体植物所反映的古生态特征探讨了油源岩形成的环境。研究结果表明,下侏罗统小煤沟组和中侏罗统大煤沟组应为该含油区的油源岩系。研究区油源岩形成于温暖湿润气候下的湖沼环境。     

准噶尔盆地三工河组标准剖面孢粉植物群

本文首次报道了准噶尔盆地三工河组标准剖面孢粉植物群：下部孢粉组合以裸子植物花粉在数量上居绝对优势,其中最为常见的有Ａｂｉｅｔｉｎｅａｅｐｏｌｌｅｎｉｔｅｓ,Ａｌｉｐｏｒｉｔｅｓ,Ｃｙｃａｄｏｉｔｅｓ,Ｐｉｎｕｓ－ｐｏｌｌｅｎｉｔｅｓ,Ｐｏｄｏｃａｒｐｉｄｉｔｅｓ,Ｑｕａｄｒａｅｄｃｕｌｉｎａ等分子;上部则表现为孢子在数量上占优势,其中Ｃｙａｔｈｉｄｉｔｅｓ和Ｄｅｌｔｏｉｄｏｓｐｏｒａ的含量较下部明     

The Sporo-Pollen Assemblage From Fuxian Formantion in Yulin-Hengshan Region,Shaanxi Province

Eighty-eight species of spores and pollen referred to 66 genera including one new species from the Fuxian Formation in Yulin-Hengshan region of Shaanxi province have been studied. The sporo-pollen assemblage may be dividied into two subassemblages. The main characters are described as follows: There are 30.7% of spores of pteridophyta. The pollen grains of gymnospermae arno:rots for 69.3%. Among the spores, those of the genus of Deltoidospora (9.2%), Cyathidites (5.6%) and Undulatisporites (4.6%) are dominant, Among the pollen grains, those of the genus Classopoilis of Chiolepidiaceae is predominant (41.8%) and Chasmatosporites(6.1%) are comparatively abundant. Besides these, there are some other Jurassic common species found in the assemblage. Comparing with the known assemblages of other places, the author considers that the Fuxian Formation belongs to Early Jurassic Lias Series. The lower part of the formation might correspond the Hettangian stage or the Simemurian Stage It: the early Jurassic, the climate should be comparatively humid with flourishing vegetation in the early stage, and hot and arid in the middle-late stage.     

民和盆地早白垩世晚期的孢粉组合

民和盆地的甘肃兰州柴家台地区,下白垩统河口组上亚组含有较丰富的孢粉化石。上亚组上部是以Ｓｃｈｉｚａｅｏｉｓｐｏｒｉｔｅｓ－Ｃｉｃａｔｒｉｃｏｓｉｓｐｏｒｉｔｅｓ为代表的孢粉组合,并可划分出上下两个亚组合,分别以Ｃｌａｓｓｏｐｏｌｌｉｓ－Ｓｃｈｉｚａｅｏｉｓｐｏｒｉｔｅｓ和Ｐｉｃｅａｐｏｌｌｅｎｉｔｅｓ－Ｃｉｃａｔｒｉｃｏｓｉｓｐｏｒｉｔｅｓ来表示。通过对主要孢粉属种地史分布规律的分析和与国内外各地同时代孢粉组合的对比,认为其地质时代是早白垩世晚期的Ａｐｔｉａｎ－Ａｌｂｉａｎ 期,上部的第二亚组合可能更晚,为Ａｌｂｉａｎ 期;孢粉化石产出的这段地层是迄今民和盆地所发现的下白垩统最高的层位