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新疆莎车地区晚白垩世孢粉组合 总被引:3,自引:0,他引:3
新疆莎车地区上白垩统英吉莎群,系一套海相与泻湖相沉积,富含孢子花粉及海相化石。本文描述了三个孢粉新属,10个新种,并对该群的地质时代、古气候及古植物区系进行了探讨,为划分对比塔里木盆地晚白垩世地层提供了孢粉学的依据。 相似文献
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浙江平山膨润土含矿地层的时代对比——兼论中国东部中生代膨润土成矿区域划分问题 总被引:3,自引:0,他引:3
根据叶肢介化石群特征和区域地层对比,并结合以往孢粉、介形虫化石资料、同位素年龄测定,浙江平山膨润土含矿地层以划归寿昌组上段为宜,时代属早白垩世。中国东部环太平洋地区中生代膨润土含矿地层层位,自北西往南东由中侏罗统经上侏罗统、下白垩统至上白垩统递升。据此可大致划分出四个膨润土成矿区。 相似文献
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通过近年来的1:20万区调工作,在青海中东部阿尼玛卿山一带,布青山群砂岩和板岩地层中,作者于玛多县花石峡,久治县章达旧址、河曲马场等多处地点,采获丰富的孢粉化石。经鉴定孢子花粉有32属61种,疑源类6属,其中主要属,种在国内外均为早三叠世代表分子。该群原划归“下二叠统”,据以上孢粉研究新资料,故布青山群的时代应订正为早三叠世沉积。 相似文献
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辽宁北部秀水盆地秀D1井孢粉组合及其地层意义 总被引:1,自引:1,他引:1
孢粉化石采自辽宁省北部秀水盆地的秀D1井,分析、鉴定和系统研究结果表明,来自秀D1井井深62.1~1089.7m的孢粉化石自下而上划分为3个孢粉组合,下部孢粉组合(井深703.85~1089.7m)以Osmundacidites-Klukisporites-Podocarpidites为代表,地质时代为晚侏罗世堤塘期(Tithonian),中部孢粉组合(井深381.5~699.3m)以Densoisporites-Cicatricosisporites-Piceaepollenites为代表,地质时代为早白垩世贝里阿斯期(Berriassian),上部孢粉组合(井深62.1~339m)以Cicatricosisporites-Impardecispora-Pinuspollenites为代表,地质时代为早白垩世凡兰吟期—欧特里夫期(Valanginian-Hauterivian)。秀D1井钻遇地层所含孢粉组合特征在区域上可以与冀北地区大北沟组,辽宁西部地区下白垩统义县组、九佛堂组,松辽盆地东南缘下白垩统火石岭组、沙河子组所产的孢粉组合对比。含孢粉组合地层时代的确定解决了井柱地层的划分,以及与区域地层的对比关系,同时为区域地层古生物研究提供了翔实的基础资料。 相似文献
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通过对江苏南部溧阳市上黄镇一露头剖面样品的分析 ,获得了丰富且保存完好的孢粉化石 ,经鉴定共 5 2属 87种。根据岩性、孢粉组合特征并与苏北及其他地区对比 ,确定含化石的地层为上白垩统泰州组 ,从而在苏南地区首次发现泰州组。这一发现不仅是对整个江苏地区泰州组地层研究的重要补充 ,而且对该区区域地质历史的重新认识 ,以及今后的石油勘探工作有着相当重要的现实意义 相似文献
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《地层学杂志》2015,(1)
青海北祁连区上三叠统实测剖面南营儿组下部的泥质页岩、炭质页岩、泥质粉砂岩中首次发现保存及分异度尚可的有机壁微体化石,共计孢粉28属35种,疑源类10属12种;其中,蕨类植物孢子占总组合的58.5%,裸子植物花粉占18.9%,疑源类占22.6%,可称为Aratrisporites-Ovalipollis-Micrhystridium孢粉组合。该组合面貌与国内外不同相区的晚三叠世的孢粉组合特征大体相似,可以对比。该组同时产植物化石Danaeopsis fecunda Halle和Neocalamites carcinoides Harris等,是一套在海侵的环境中形成的河湖相沉积,当时气候温暖潮湿。 相似文献
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青海西宁-民和盆地渐新世至中新世孢粉组合 总被引:17,自引:1,他引:17
1975年—1980年青海省石油普查勘探大队对西宁-民和盆地上白垩统至上第三系进行了综合研究。我们曾对十条剖面,近1300块样品进行了孢粉分析,其中327块样品含有较丰富的孢粉,为研究本盆地晚白垩世至第三纪的古地理及其地层划分提供了古生物依据。本文将依据孢粉资料,探讨本盆地渐新统至中新统的划分对比及上、下第三系界线。在工作中青海石油队的地质人员给予了大力协助。孢粉分析由李光瑜、莫新功、边青兰负责。照像由陈殿丰、宋坤民担任,在此表示谢意。 相似文献
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KENNETH NEIL MERTENS CATALINA GONZÁLEZ IRINA DELUSINA STEPHEN LOUWYE 《Boreas: An International Journal of Quaternary Research》2009,38(4):647-662
Dinoflagellate cysts and other palynomorphs were studied from ODP Hole 1002C in the Cariaco Basin over the past 30 000 years. The assemblage shifts between a dominance of heterotrophic dinoflagellate cysts (mainly Brigantedinium spp., Lejeunecysta spp., Selenopemphix nephroides and Stelladinium reidii ) and autotrophic dinoflagellate cysts (mainly Spiniferites ramosus , Lingulodinium machaerophorum and Operculodinium centrocarpum ). These assemblage shifts are associated with stronger upwelling during stadials and stronger river influx during interstadials. Increases in productivity caused by enhanced upwelling are coupled to improved preservation and vice versa. More stratified water is indicated by higher abundances of L. machaerophorum and succeeds Heinrich events. The average process length of L. machaerophorum can be used to track changes in salinity, since this shows a similar pattern as the δ18 OSW (paired Mg/Ca −δ18 O) reconstruction. During the last glacial, conditions were more saline than during the current interglacial. On a millennial scale, changes in salinity are opposite to open ocean salinities and the hydrological proxies, which can be explained by a modulation of the signal by stratification, isolation of the Basin or advection of freshwater masses. These results highlight both generalities and particularities of the palaeoecological record of this tropical semi-enclosed basin. 相似文献
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上扬子区下志留统四射珊瑚组合带与层序地层序列的关系 总被引:2,自引:0,他引:2
摘 要 根据动物群演替和层序地层的研究厘定上扬子区下志留统 (Llandovery) 四射珊瑚
组合带序列:(1) 香树园组 Dinophyllum-Rhabdocyclus 组合带时限为 Aeronian 期;(2) 雷家
屯组下部 Stauria-Briantelasma 组合带; (3) 雷家屯组上部 Maikottia-Kodonophyllum 组合带
它们对应于 Telychian 早期;(4) 宁强组 Gyalophylloides -Idiophyllum 组合带相当于 Telychian
晚期。上扬子区下志留统可以划分为5个三级层序四射珊瑚组合带分别位于三级层序的高
水位体系域内。 相似文献
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A total of 85 samples, collected from the UBGH1-9 core taken from the Ulleung Basin, East Sea, Korea, were analyzed using diatom assemblages. 111 diatom species belonging to 46 genera were identified, and three diatom assemblage zones were established on the basis of occurrence and distribution pattern of diatoms. Diatom assemblage zone I(134.10–174 m) is characterized by a relatively high abundance of marine species, while the increased number of the brackish species is recorded in diatom assemblage zone II(75–125 m). The assemblage zones IIIa became drastic drop of valve abundances and brackish planktons, whereas it became increase during the IIIb. High Td values which indicate an influence of warm current are recorded both in diatom assemblage zone I and III, and low Td values in diatom assemblage zone II. Analysis of diatom assemblages indicating that the depositional condition moved from oceanic to littoral-neritic environments and that paleotemperature underwent a shift from warm to cold condition at the middle interval, and from cold to warm condition in the upper interval of the UBGH1-9 core. This suggests that the lower(130–162 m) and upper intervals(0–20 m) of the UBGH1-9 core were deposited in the warm current condition(Tsushima Warm Current). 相似文献
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皖南地区广泛分布着溪口群浅变质岩地层,尽管对其进行了大量的研究,但关于地层时代的归属问题仍存在很大争议。在皖南溪口群采集的43件样品中发现较丰富的陆生植物孢子(Spoers)20余属,50余种,其中具有地层意义的孢子有15属25种。这些孢子组合可与中国华南、西南、西北地区及新疆塔里木盆地巴楚地区晚泥盆世晚期孢子带相比较,也可与西欧、东欧和北美地区晚泥盆世法门阶(Famennian)孢子带对比,其时代为晚泥盆世晚期,相当于西欧晚盆世晚期法门阶(Famennian)。 相似文献
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Dinoflagellate cysts in Upper Quaternary sediments from southwestern Norway and potential correlations with the oceanic record 总被引:1,自引:0,他引:1
Twenty-two samples from two locations at the Foss-Eigeland clay and gravel pit, Jæren, southwestern Norway were analysed for dinoflagellate cysts. Cyst recovery was generally poor and cyst assemblages indicate a cold temperate to arctic glacimarine environment. The percentage composition of a total of 19 cyst species identified allowed the recognition of five assemblage zones. These are thought to reflect fluctuating minor climatic changes during an interstadial period preceding the last glacial advance in the region. Cyst assemblages from these supposedly Middle Weichselian sediments at Foss-Eigeland are similar to those found in the northern North Sea and the Norwegian Sea in probably similarly aged sediments. This suggests a potential for using dinoflagellate cysts to correlate land-based Quaternary sequences with the deep sea record. 相似文献
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To investigate the distributions of dinoflagellate cysts in relation to environmental conditions from southern coast of Korea,
surface sediment samples collected from 11 stations in Gamak Bay, Yeoja Bay and the offshore area of Yeoja Bay were analyzed.
Dinoflagellate cyst assemblages observed in the study area included many species commonly reported from other temperate regions.
Among them, Polykrikos cysts were dominant, together with Brigantedinium spp. and Spiniferites spp. Based on cluster analysis, dinoflagellate cyst assemblages were divided into two main groups; group I, located in Yeoja
Bay and group II, located in Gamak Bay and the offshore area of Yeoja Bay. Principal component analysis identified differences
in salinity levels as the main environmental factors affecting the distributional characteristics of dinoflagellate cyst assemblages
in the study area. Gamak Bay is a typical eutrophied area as result of extensive human activities around the bay, and heterotrophic
cysts, including Polykrikos cysts, are remarkably abundant and likely to be a useful indicator for eutrophication in Gamak Bay. 相似文献
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内蒙古温都尔庙地区温都尔庙群的形成环境和构造意义 总被引:7,自引:1,他引:6
内蒙古温都尔庙地区有一套统称为温都尔庙群的变质岩系,该岩系主要由两种不同的岩石组合组成:一套是出露于乌兰沟一带的浅变质岩系,主要由变玄武岩、硅质岩、火山碎屑岩、碎屑岩组成的基性火山岩-碎屑岩组合;另一套是出露于德言其庙一带的深变质岩系,主要由斜长角并岩、斜长片麻岩组成。这两套岩石组合在变形变质、岩石化学和形成环境等方面都有很大的差异,前者主要表面出弧后盆地的特征,后者则是拉张过程中板底垫托的产物,它们分别代表了华北板块北缘中元古代不同构造演化阶段的产物。 相似文献