首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 109 毫秒
1.
The palynological assemblage from Wulaga dinosaur site in Jiayin from southeastern Zeya-Bureya Basin was studied. The high content of pteridophytes spores is characteristic for this assemblage. The further characters are in decrease of abundance-tricolpate pollen, Ginkgocycadophytus, pollen of Taxodiaceae, Cupressaceae and Taxaceae (TCT) , bisaccate pollen of Pinaceae, and triporate pollen. The bone-bearing burials of Wulaga dinosaur site formed under conditions of vast swampy river valley covered by ferns and taxodialeans. Tricolpate pollen, produced by plants, close to those of Platanaceae, Fagaceae, Betulaceae, and Juglandaceae, counts in favor of valley river open canopy forests.  相似文献   

2.
宁波盆地地下揭示的一套包含暗色膏硝质泥岩、泥质白云岩在内的紫红、灰紫色泥岩、棕褐色砂砾岩、细砂岩和玻屑凝灰岩的地层,均称方岩组,内含膏盐并具油色显示。对其时代有早、晚白垩世和早第三纪之认识,笔者从70~90年代地质工作中所获化石分析认为,虽然宁波盆地这一层位含化石不丰,但从分布及数量上比较,相对占优势的应该是孢粉和植物化石,其时代意见也较为一致,指示为早白垩世。  相似文献   

3.
孢粉浓度统计法在西北土类堆积物的应用   总被引:1,自引:0,他引:1  
本文以宁夏水洞沟全新统剖面为例,运用孢粉浓度统计法对我国西北地区土类堆积物进行了初步研究,并与传统的孢粉百分比统计法所得结果进行了对比。文中,运用电子计算机进行了孢粉资料整理,划分出了七个孢粉组合带,基本上符合我国北方全新世气候变化的一般规律。结果表明,两种方法所反映的古植被、古气候变化趋势基本一致。在孢粉数量丰富的情况下,孢粉浓度统计在图式上表现得更突出和明显;在孢粉数量较少时,用百分比统计法更便于说明问题。  相似文献   

4.
通过对唐口二叠纪孢粉组合的分析研究,建立了该区二叠纪3个孢粉组合带,①Densosporites(套环孢)-Crassispora(厚环孢)组合;②Gulisporites(匙唇三缝孢)-Sinulatisporites(曲环三缝孢)组合;③Anticapipollis(逆沟粉)-Macrotorispora(大一头沉孢)组合。这3个组合带分别反映太原组、山西组、下石盒子组及上石盒子组的孢粉组合面貌,其地质时代分属于早二叠世、中二叠世,晚二叠世早期。  相似文献   

5.
The results of the palynologic and paleobotanic analyses have allowed determining the Paleocene (including Danian) and Eocene deposits in the series of coal-bearing sediments of southeastern flanks of the Raichikhinsk brown coal field. Their age was corroborated by the palynologic and paleobotanic data. The detailed biostartigraphic data were obtained in the area““ Pioneer““ for the first time. The coal-bearing strata were correlated with those from the sections of the Arkhara-Boguchan brown coal field and the stratotype of the Tsagajan Formation of the Bureya Belogor‘ye.  相似文献   

6.
7.
胜利油区第三纪气候   总被引:1,自引:0,他引:1  
胜利油区第三纪气候温暖 ,属亚热带型。早第三纪气候暖热 ,一般属中亚热带型。沙河街组沉积时期为增温期 ,气候属南亚热带型 ;孔二段及东一段沉积时期为降温期 ,气候属北亚热带型。晚第三纪气温下降 ,但仍较温暖 ,馆下段沉积时期气候属北亚热带型、馆上段沉积时期气温上升 ,为中亚热带型 ;明化镇组沉积时期气温再度下降。研究区第三纪有一个潮湿期即孔二段沉积时期 ,两个湿润期即沙三段、沙一段中部至馆陶组沉积时期 ;三个干旱期即孔一段至沙四段、沙二段上部至沙一段下部、明化镇组沉积时期。  相似文献   

8.
三个钻孔的岩心表明,南李庄泻湖沉积可分为5层,最大厚度15m左右。根据孢粉、微量元素以及岩相特点可将泻湖的演化分为5个阶段。资料表明,湖水变深时期是气候温湿时期,湖水变浅时期为气候凉干时期,指示泻湖的兴衰明显受气候控制。  相似文献   

9.
广西百色盆地第三系孢粉化石极为丰富。根据大量孢粉分析鉴定资料,共建立7个孢粉组合及6个亚组合,其时代分别代表早第三纪中-晚始新世、晚始新世、渐新世以及晚第三纪上新世。  相似文献   

10.
笔者近年从事河南二叠系山西组地质工作,分析鉴定孢粉化石1473个。计62个属,89个种,6个近似种,62个未定种,2个疑源类属。其中,三缝孢占59.4%,单缝孢占33.1%,花粉占4.7%,疑源类占2.8%。通过综合分析对比,笔者认为:山西组孢粉组合特征与国内、外同时代地层中的孢粉组合特征基本一致;孢粉的属、种变化与山西组所产动、植物化石有相关性,并进一步佐证了山西组煤层的成煤环境属滨海潮坪和三角洲分支流间湾环境。  相似文献   

11.
通过对四川红原日干乔泥炭剖面的孢粉研究,建立了4个孢粉组合带。自13.6ka以来,日干乔地区古气候经历了以下演化阶段:13.688~11.093ka以温湿气候为主,11.093~8.512ka气候较为干旱,2.74~5.39ka,8.512~5ka气候转暖,温和湿润,5ka至今,该地区气候环境最好,温暖湿润。孢粉组合特征显示该区在此阶段总体为温湿的草原环境,孢粉记录反应了红原县日干乔地区第四纪更新世经历了潮湿—干燥—潮湿的气候变化过程。  相似文献   

12.
冰后期长江河口段古河谷地层层序特征   总被引:2,自引:0,他引:2  
末次盛冰期,由于基面大幅度下降,长江河口段形成了深切古河谷。河流携带的部分粗砂砾在河床上形成滞留沉积。冰后期海平面上升引发的海侵造成了长江古河谷的充填和河床相、河漫滩河口湾相和部分河口湾浅海相的形成。尔后的进积产生了部分河口湾浅海相及三角洲相。根据钻孔资料绘制的古河谷地质剖面图显示,冰后期海侵旋回出现在三角洲顶点到现在河口口门地区,溯河而上受海洋影响的程度逐渐减弱。古河谷的中部,靠近主泓线附近,沉积层序完整。古河谷的边缘地带,往往缺失底部的河床相砂砾层。底部的厚层河床相砂砾层是由河床滞留沉积和溯源加积堆积形成的,在古河谷沉积层序中存在着多种沉积间断。  相似文献   

13.
本文通过钱塘江深切谷的论述对末次冰期深切谷的恢复主要依据下列证据进行:(1)谷底为侵蚀不整合面,为末次冰期海平面下降,河流侵蚀切割所致;(2)谷内为异常厚的河流沉积物所充填,是冰后期海平面上升时形成,其中河漫滩沉积年代约14000~7500a以前;(3)深切谷之上被海相地层覆盖。超浅层生物气田分布在深切谷内,当今河流及全新世晚期河口湾与末次冰期深切谷既有区别又有继承性,其流域是浅层生物气藏分布的有利地段。  相似文献   

14.
Detrital minerals of 137 offshore and 22 river sediment samples collected from Qingdao coastal areas have been analyzed. Four mineral assemblage provinces can be classified by Q-mode cluster analysis. Factor analysis identifies two major factors that account for the total variability in most common minerals: 1) based on the relationship of quartz, hornblende, actinolite, micas, and authigenic pyrite, 41.55% of the variability is related to sediment sources; 2) based on the relationship of epidote, garnet, sphere, and ilmenite, 23.21% can be related to strong hydrodynamic conditions that control transport and sedimentation. By comparing mineral compositions of river waters in the study area, the following four mineral provenances can be identified. The Qingdao-Laoshan nearshore area has a quartz-feldspar-epidote-hornblende-limenite-limonite-sphene assemblage, which is largely attributed to relict sediment and coastal erosion. The Jimo-Haiyang nearshore area has a quartz-feldspar-hornblende-epidote-limonite-mica-actinolite assemblage, derived largely from the Wulong River and Rushan River, and is also affected by the Huanghe River, while the Qianliyan Island area in the deeper offshore area separated by a mud belt has a similar assemblage. The Haiyang-Rushan nearshore area has a quartz-feldspar-hornblende-epidote-micas-limonite assemblage, indicating multiple sources from the Rushan River, the Wulong River, the Huanghe River, and coastal erosion. The central area, located in an eddy center, has a mica-authigenic pyrite-hornblende-quartzfeldspar assemblage, indicating multiple sources dominated by Huanghe River distal sediments.  相似文献   

15.
应用误差反向传播算法的人工神经网络,建立了流域年均含沙量的预测模型。该模型用于某流域年均含沙量预测的拟合率达90%以上,预留检验预报的准确率为75%。  相似文献   

16.
A new dinosaur tracksite was discovered in a steeply inclined sandstone layer of the Middle Jurassic Sanjianfang Formation in the Shanshan area of the Turpan Basin. The site is the first record of dinosaur footprints from Xinjiang Province in northwestern China. More than 150 tridactyl theropod dinosaur footprints are preserved as positive hyporeliefs on the lower bedding plane of a fine-grained sandstone body. Most of the footprints are isolated and appear to be randomly distributed. Some show well defined phalangeal pads, heels and rarely indistinct impressions of the distal part of the metatarsus. Two distinct morphotypes are present: a larger type with relatively broad pads shows similarities to Changpeipus and Megalosauripus, and a slightly smaller, slender and gracile type which is similar to Grallator, Eubrontes and Anchisauripus. In both morphotypes, digit III is the longest with a length between 11.4 and 33.6 cm. A single imprint shows prominent scratches, probably formed during slipping of the track maker.  相似文献   

17.
该文对河南省恐龙蛋化石的分类和命名、恐龙蛋化石在各个沉积盆地中的分布特征以及恐龙蛋化石的新类型进行了扼要综述。从含蛋岩层的岩性、蛋化石埋藏的古微地貌、蛋化石在岩层中的分布和排列方式及保存形式、恐龙蛋与恐龙骨骼化石和其他生物门类化石的共生以及恐龙蛋化石的共生组合特征等方面论述了恐龙蛋化石的埋藏特征。对恐龙的生活方式、产蛋方式及生态习性、恐龙蛋化石大量富集的机理及恐龙蛋“挂”在石板下的原因等问题进行了探讨。最后对DNA和CT扫描研究进行了评述  相似文献   

18.
A new dinosaur tracksite was discovered in a steeply inclined sandstone layer of the Middle Jurassic Sanjianfang Formation in the Shanshan area of the Turpan Basin. The site is the first record of dinosaur footprints from Xinjiang Province in northwestern China. More than 150 tridactyl theropod dinosaur footprints are preserved as positive hyporeliefs on the lower bedding plane of a fine-grained sandstone body. Most of the footprints are isolated and appear to be randomly distributed. Some show well defined phalangeal pads, heels and rarely indistinct impressions of the distal part of the metatarsus. Two distinct morphotypes are present: a larger type with relatively broad pads shows similarities to Changpeipus and Megalosauripus, and a slightly smaller, slender and gracile type which is similar to Grallator, Eubrontes and Anchisauripus. In both morphotypes, digit III is the longest with a length between 11.4 and 33.6 cm. A single imprint shows prominent scratches, probably formed during slipping of the track maker.  相似文献   

19.
Introduction The Himalaya is considered to be the youngest mountains on the earth, and is tectonically very active, and hence inherently (geologically) vulnerable to hazards. Extreme rainfall events, landslides, debris flows, torrents and flash floods due…  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号