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1.
Flora from the lower Norian deposits of the Upper Triassic, which are exposed in the Partizanskaya River basin, has been studied in detail. A new Imalinovo floral assemblage is distinguished. As is established, its taxonomic composition is represented by abundant cycadophytes and conifers occurring in association with insignificant ferns and czekanowskialeans, rare horsetails, pteridosperms, and ginkgoaleans. The studied floral assemblage is compared with several floras of East Asia: the Mongugai flora of Primor’e, the Tianqiaoling flora of northeastern China, the Yamanoi and Nariwa floras of Japan. 相似文献
2.
川北广元须家河组一段沉积相与沉积环境演化分析 总被引：2，自引：2，他引：0
四川盆地北部三叠系—侏罗纪发育,出露良好,是三叠纪—侏罗纪转换时期古气候与古环境变化的良好物质记录。其中,晚三叠世诺利期是四川盆地海陆转换的重要过渡期,尤其是对陆地生态系统的影响更加显著。以川北广元剖面为研究对象,对晚三叠世诺利期末须家河组须一段进行沉积相及沉积环境演化的分析,结果表明:研究剖面发育潟湖沼泽—三角洲平原—辫状河流亚相沉积,为海陆过渡相—陆相沉积体系;受甘孜—阿坝弧后盆地发育影响,始自卡尼期的海侵自诺利中后期到达广元地区;在秦岭造山带及龙门山的隆升背景下,广元地区较早结束海陆过渡相沉积,于须一段中后期向河流相沉积转变。结合对古生物化石组合研究和岩性特征及沉积相,恢复了广元地区晚三叠世诺利期须一段的古气候特征,广元地区须一段处于近海亚热带潮湿气候,这种潮湿气候从须一段一直延续至诺利期末期。 相似文献
3.
《International Geology Review》2012,54(4):716-723
The Tortonian (Miocene) flora of Swoszowice in the Cracow region is analyzed taxonomically and floristically. This flora, which was first described by Unger and Stur in the last century, is con-- siderably revised; of the 31 specific entities recognized, several are of wide occurrence in the Eurasian Neogene. About one-third of the flora is composed of the Poltavan element, i.e., exotic broad-leafed evergreens related to extant tropical to subtropical species. The remainder of the flora is composed of conifers and deciduous angiosperms related to extant warm-temperate to subtropical species (Turgayan element). Comparison of the Swoszowice flora with the Pliocene floras of Transcarpathia indicates that the latter are composed predominately of Turgayan species that were present in the Swoszowice flora. The warm Poltavan element, however, was eliminated in the interval — estimated to be between 8 and 11 million years — between the Swoszowic and Transcarpathian Pliocene floras, thus indicating a deterioration of climate. --J. A. Wolfe. 相似文献
4.
Hard substrate photophilius marine algae species of the Saronikos Gulf amount to 197. Of them, 42 were Atlantic subtropical, 36 Atlantic tropical, and just 19 Atlantic boreal and 11 Boreal. The R/P ratio was 3.22. This shows the Atlantic subtropical character of the marine flora. 相似文献
5.
6.
在北京市门头沟区九龙山南坡中侏罗统的下窑坡组、上窑坡组和龙门组采集植物化石22属38种。统计资料表明,北京西山中侏罗世植物群以真蕨纲(27.6%)、苏铁纲(25%)和银杏纲(25%)为主,其中真蕨纲的Coniopteris、Cladophlebis分别出现5和17个形态种。本文通过现生近缘种类分析法和植物的生长状态分析研究古气候。研究表明,含量高的植物化石的现生近缘种类紫萁科、蚌壳蕨科和苏铁纲植物主要生长于温热潮湿的热带或亚热带气候区;Cladophlebis较高的分异度,苏铁纲大型的羽状复叶,木贼目宽大的茎干等植物特征,同样指示较为湿热的气候环境。因此,北京西山中侏罗世植物群反映一种温热潮湿的亚热带气候。并且,化石的属种和数量自下窑坡组、上窑坡组到龙门组的降低反映研究区气候由温热潮湿向干热方向的演变。 相似文献
7.
M. Chandra Singh R. A. S. Kushwaha Gaurav Srivastava R. C. Mehrotra 《Journal of the Geological Society of India》2012,79(3):287-294
Some plant remains are described from the Laisong Formation (Barail Group) of Thoubal and Senapati districts of Manipur. The
flora is diverse comprising gymnospermous, monocotyledonous and dicotyledonous forms and indicates tropical to subtropical
climate in the vicinity of the area during the deposition of the host rocks. 相似文献
8.
Luis M. Sender Jos B. Diez Javier Ferrer Denise Pons Cristbal Rubio 《Cretaceous Research》2005,26(6):898-905
A newly discovered plant fossil assemblage in the Albian Escucha Formation, located at Valle del Río Martín (Teruel, Spain), shows similarities with the classic early Cretaceous flora of the Potomac Group in the USA. This is the first time that a flora of this age and composition has been found in Spain. It comprises representatives of ferns, Ginkgoales, Bennettitales, Caytoniales, conifers and angiosperms and suggests a possible mixing of the European and Potomac provinces in the early Cretaceous within the Iberian Peninsula, in a subtropical, semi-arid climate. 相似文献
9.
《International Geology Review》2012,54(9):1017-1022
In the course of investigations in the North Caucasus, the Pamirs and the Soviet Northeast, geologists observed in sections certain beds with a peculiar fauna, underlain by deposits of the Norian stage and overlain by Upper Jurassic deposits. According to I. I. Tuchkov, in the Soviet Northeast these beds are unconditionally referred to the Rhaetian. In 1959 A. I. Afizky found numerous Upper Norian ammonites within these deposits on the Bolshoi Anyui River (lower course of the Kolyma River). As early as 1937 J. Fromaget mentioned findings of Norian ammonites in the supposedly “Rhaetian” beds in south-Asian sections. This author first put forward the Rhaetian stage problem, suggesting that it might be regarded as a zone of the Norian stage. Such a solution of the Rhaetian stage problem breaks with traditional stratigraphy. The present paper points out another way towards the solution of the above problem, taking into account both the numerous cases of findings of beds with a mixed Norian-Rhaetian fauna and the irregular distribution of ammonite zones in the Norian (six zones) and the Rhaetian (one zone) stages. By lowering the lower boundary of the Rhaetian stage and including the two upper zones of the Norian stage into the Rhaetian, the problem, of the latter may be solved without breaking with traditional stratigraphy.—Auth. Eriglish summ. 相似文献
10.
内蒙古赤峰市敖汉旗水泉南山附近采集到酒局子组植物化石,通过系统鉴定,共计12属18种,包括楔叶类、木贼类、瓢叶类、真蕨和种子蕨类及科达类等,其中以Pecopteris (Asterotheca) hemitelioides和Cordaites principalis为代表,均为晚古生代华夏植物群常见分子或代表分子,表明赤峰地区在宾夕法尼亚亚纪时应属华夏植物地理大区.酒局子组的时代应当归于宾夕法尼亚亚纪.植物群中发现高大的科达类,并有大量反映热带、亚热带气候的真蕨和种子蕨类,显示该区当时应处于亚热带-暖温带雨量充沛的湿热环境. 相似文献
11.
陇东三叠系延长组主要油源岩发育时期的古气候特征 总被引：9，自引：3，他引：9
鄂尔多斯盆地西南部陇东地区延长组长8段和长7段分别发现以Aratisporites- Punctatisporites和Asseretospora-Walchiites为代表的孢粉组合,时代分别为中三叠世晚期与晚三叠世早期。通过现生主要植物类型生态环境分布规律的讨论和孢粉植物群已知亲缘关系类型的地层分布特征研究,推测陇东地区中晚三叠世气候温暖潮湿,雨量充沛,植被茂盛。孢粉植物群反映的古气候为温带—亚热带暖湿或湿热气候。孢粉植物群特征与孢粉化石分异度曲线都表明,本地区长8—长7段沉积时期为持续温暖潮湿的适宜期, 与湖泊发展的长8期大规模湖进和长7期的最大湖泛相一致。孢粉植物群具有北方植物群的明显特征,由于本地区当时濒临大型湖泊,而且长8—长7段沉积时期正处于湖泊扩张的鼎盛期,因此显示出更为湿润的古环境特征。正因为长期稳定温暖潮湿气候和广大的深水湖泊环境为水生藻类的大规模发育创造了条件,从而为本地区长7期优质烃源岩的形成提供了母质来源。 相似文献
12.
本文对产于甘肃窑街中侏罗统窑街组地层的植物大化石进行了系统的研究,发现甘肃窑街中侏罗世植物群由31属63种组成。其中,银杏类植物7属23种,真蕨类植物7属14种,松柏类植物7属11种,苏铁类植物5属10种,楔叶类植物4属4种,分类位置不明化石1属1种。在研究植物群组成特征的基础上,通过对植物化石埋藏类型与化石类群生态学的分析,重建了古植物群落,总结了窑街植物群的古生态特征,并划分出四个群落,即划分为近岸湿地群落、山间低地—缓坡群落、山间高地群落、旱生群落等四个群落。根据植物群的整体特征、植物类群之间的比例关系、特征分子及其古生态特征及孢粉植物群特征,推断甘肃窑街盆地中侏罗世古气候为温暖潮湿的亚热带气候。Brachyphyllum及茨康目植物化石的存在,表明甘肃窑街中侏罗世气候环境存在季节性变化。 相似文献
13.
WANG Daning 《Continental Dynamics》1999,(2)
1.IntroductionTheYuanquBasinisoneoftheearliestst-UdiedCenozoicinlandbasinsinChina.Duetotheabun-dantmammalfossilsexcavatedfromthePaleogenestrataofthebasin,especiallythecompIeteandsuc-cessivestrataaswellasvariousabundantmammalfossilsofLateEocene,whichprovidesasufficientfoundationforthedeterminationofstratigraphicalage,itisregardedasaremarkablecriterionforcor-relationwithotherbasins.TheYuanquBasinIiesatthesouthemmarginoftheNofthChinaplatform,theFigurel.1ndexmapshowingthelocationoftheYuanqu… 相似文献
14.
The flora and vegetation of Central Eurasia evolved in the Paleogene to a significant extent in line with the scenario similar to the Late Cretaceous one. The position of high-rank phytochores was controlled by the global climatic zonality, while development stages of the flora depended on interaction between the Arctic and Tethyan water masses and direction of atmospheric flows and were determined by principal geological and paleogeographic events in the Paleogene history of Central Eurasia. Five main stages are definable in development of the Paleogene flora: (1) early-middle Danian with the wide distribution of temperate-thermophilic floras in the middle and high latitudes and their westward and southward expansion from the Pacific and Arctic regions of the Boreal realm; (2) Late Paleocene-Early Eocene with the maximal advancement of the Tethyan flora to the high latitudes and northward migration of phytochore boundaries in response to intense water exchange between the Tethys and Atlantic oceans with its trade currents and atmospheric heat transfer directly from the tropical zone in absence of the Alpine-Himalayan orogen; (3) Lutetian with development of subtropical monsoon-type floras under influence of the water mass exchange between the Arctic Basin and Peritethys with the monsoon-induced currents and atmospheric heat transfer from the Peritethys under conditions of the restricted connection between the Central Asia basins and Tethys; (4) (?) late Lutetian-Priabonian reflecting the climate inversion due to isolation of the West Siberian Sea from the Arctic Basin against the background of its continuing connection with the Peritethys; the formation of the semiclosed West Siberian Sea at that time was accompanied by development of a climate with humid winters, hot dry summers, and deficiency of average annual precipitation in the middle latitudes of Central Eurasia, where luxuriant subtropical Quercus-Laurus forests with Castanopsis that prevailed at the preceding stage were replaced by sclerophyllous arboreal-frutescent maquis; (5) Oligocene marked by the formation of the temperate deciduous mesophyllous coniferous-broad-leaved Turgai flora after definitive desiccation of the West Siberian Sea and Turgai Seaway due to global regression induced by glaciation (transition from the “warm” to “cold” biosphere). 相似文献
15.
第三纪青藏高原面高程与古植被变迁 总被引：18，自引：0，他引：18
收集了近半个世纪以来、几乎全部有关青藏高原第三纪古植被的研究资料,从整体角度对青藏高原的古植被演化史与高原面高程变化史进行了初步研究。认为青藏高原第三纪古植被经历了由古老、湿热环境下的热带低地森林,脉动式地渐变为热带、亚热带山地森林及灌丛草原。反映高原是阶段性、持续上升的,其间不存在大幅的降低过程。冈底斯山、念青唐古拉山、唐古拉山、昆仑山所围限的藏北高原比喜马拉雅山系隆升早,且在整个第三纪都比喜马拉雅山高,到上新世的中、晚期其高度已达海拔３０００ｍ以上。喜马拉雅山系成为世界屋脊是第四纪以来的事。 相似文献
16.
Pergamidia在川西昌台纳楞海三叠系的发现及时代意义 总被引：1，自引：0，他引：1
对于Pergamidia的时代,一直存在不同的观点:多数人认为它是诺利克期的典型化石,但也有认为其时代为卡尼克期至诺利克期,以Pergamidia为主的化石组合则出现在诺利克期。在四川西部昌台地区的纳楞海—国营种畜场剖面中,产出了大量的双壳类化石,包括前人发现的双壳分子组合Halobia yunnanensis-Halobia pluriradiata(Hy-Hp组合)及本次观测纳楞海剖面时采集的以Pergamidia属的分子为主的新化石组合,由Pergamidia eumenea,Pergamidia attalea,Pergamidia timorensis,Pergamidiaeumenea hoqingensis等组成。新化石组合在该剖面中的层位位于Hy-Hp组合的底部,资料证实Hy-Hp组合为卡尼克中、晚期典型化石组合。区域上的Perga-midia时代延限为卡尼克期—诺利克期,以Pergamidia属为主的双壳类化石组合面貌既可以出现于诺利克期也可出现在卡尼克期;川西昌台地区的Pergamidia在具有酸性火山活动末期的环境中聚集、繁盛,并从纳楞海开始向周围环境扩散。 相似文献
17.
Gordon M. Walkden Nicholas C. Fraser Michael J. Simms 《Proceedings of the Geologists' Association. Geologists' Association》2021,132(1):127-137
In the Late Triassic the landscape NE of present-day Bristol, SW England was dominated by Carboniferous Limestone ridges and cuestas that became progressively buried by continental Mercia Mudstones and finally inundated during the Rhaetian marine transgression. Mussini et al. (2020) adopt the assertions of earlier collaborators back to Whiteside and Marshall (2008) that terrestrial vertebrate assemblages from sediments contained within karstic fissure systems in the former limestone ridges at Cromhall, Tytherington and elsewhere are restricted to the Rhaetian. We review and reject the sedimentological, stratigraphic, geomorphological and topographic arguments for this and reassert a long pre-Rhaetian (Norian) history for the vertebrate-bearing fissure systems at both Tytherington and Cromhall. We also reject the contemporaneous Rhaetian freshwater-seawater mixing zone dissolution model for the fissure systems adopted by Mussini et al. (2020) and reaffirm that the Tytherington and Cromhall fissures developed as conduit caves with a long Triassic history. Applying a new regional study of the Rhaetian transgressive surface, we also show that whilst the fissures at Cromhall remained sealed after the Norian, those at nearby Tytherington were re-exposed in the Late Rhaetian. Already partially filled with Norian sediments, the Tytherington fissures were subject to reworking on the seabed. Internal collapses, probably triggered by well documented repeated regional seismicity, led to the chaotic state of the Tytherington fills when downward moving Rhaetian marine components came to lie amongst and mix with earlier Norian terrestrial sediments. The vertebrate associations in the Tytherington fissures therefore contain a substantial Rhaetian input whilst those at Cromhall do not. 相似文献
18.
新的地层和古生物学研究结果表明,措勤盆地在晚古生代一早中生代不存在长达75Ma以上的沉积间断．其中,晚二叠世-晚三叠世诺利期都是海相碳酸盐岩地层,晚三叠世瑞替期-早中侏罗世为陆缘碎屑岩地层．两者之间为角度不整合接触．措勤盆地在晚二叠世-晚三叠世诺利期一直处于海相碳酸盐岩盆地中．晚三叠世瑞替期-早中侏罗世仍然是接受巨厚沉积的低洼地区。从宏观的油气勘探的战略评价角度看．措勤盆地在中二叠世栖霞期-晚三叠世诺利期的海相碳酸盐岩地层具有生油层的性质,上三叠统瑞替阶-中下侏罗统具有盖层的性质,两者之间的角度不整合具有储集层的性质。措勤盆地中二叠统-下侏罗统构成一个油气的有利勘探层系．称为古格层系。 相似文献
19.
对贺兰山地区上田组的植物化石开展研究,此次鉴定出12属14种,结合前人资料,上田组植物化石共计20属35种。其中,真蕨纲和种子蕨纲9属19种,占54%;苏铁纲4属6种,占17%;楔叶纲1属4种,占11%;松柏纲3属3种,占9%;银杏纲2属2种,占6%;分类位置不明的种子1属1种,占3%。该地区植物化石组合以中国北方型Danaeopsis-Bernoullia植物群的属种占主导地位,同时混生了中国南方型Dictyophyllum-Clathropteris植物群的分子Dictyophyllum,且苏铁类占一定的比例,反映了晚三叠世末期贺兰山为半干旱的亚热带大陆型气候,且正在向湿热发展。 相似文献
20.
西藏措勤盆地的上古生界—下中生界：潜在的油气沉积建造 总被引：2，自引：1，他引：1
新的地层和古生物学研究结果表明,措勤盆地在晚古生代一早中生代不存在长达75Ma以上的沉积间断．其中,晚二叠世-晚三叠世诺利期都是海相碳酸盐岩地层,晚三叠世瑞替期-早中侏罗世为陆缘碎屑岩地层．两者之间为角度不整合接触．措勤盆地在晚二叠世-晚三叠世诺利期一直处于海相碳酸盐岩盆地中．晚三叠世瑞替期-早中侏罗世仍然是接受巨厚沉积的低洼地区。从宏观的油气勘探的战略评价角度看．措勤盆地在中二叠世栖霞期-晚三叠世诺利期的海相碳酸盐岩地层具有生油层的性质,上三叠统瑞替阶-中下侏罗统具有盖层的性质,两者之间的角度不整合具有储集层的性质。措勤盆地中二叠统-下侏罗统构成一个油气的有利勘探层系．称为古格层系。 相似文献