中国陆相上新统麻则沟阶   总被引：1，自引：0，他引：1  

邓涛  侯素宽 《地层学杂志》2011,(3):237-249

年代地层单位麻则沟阶是中国上新统的两个阶之一,代表陆相上上新统,1999年由第二届全国地层委员会正式命名,对应于麻则沟期。"麻则沟"一名源自同名岩石地层单位麻则沟组,典型剖面位于山西省榆社县云簇镇赵庄—大马岚。麻则沟阶对应于"国际地层表"中的皮亚琴察阶,其共同的底界定义为古地磁Chron C2An.3n的底,即高斯正极性带的底,绝对年龄为3.6 Ma,这条界线在榆社赵庄剖面位于第6层麻则沟组下部的紫红色黏土层的中部,以张洼沟姬鼠(Apodemus zhangwagouensis)的首现为标志。麻则沟期与欧洲陆生哺乳动物分期的Villa-nyian早期或Villafranchian早期相当,包含1个哺乳动物群单位,即NMU13,可与欧洲的MN16对比。在榆社盆地发现的麻则沟动物群就相当于NMU13。在中国的上新世哺乳动物群中,甘肃灵台的任家沟动物群和雷家河V带动物群、河北阳原泥河湾的稻地动物群、陕西渭南的游河动物群、山西静乐的贺丰动物群、四川德格的汪布顶动物群也相当于NMU13。河北泥河湾的花豹沟剖面是麻则沟阶的辅助层型剖面。  相似文献   

The effect of the Messinian Deep Stage on karst development around the Mediterranean Sea. Examples from Southern France     

《Geodinamica Acta》2013,26(6):389-400

It is difficult to explain the position and behaviour of the main karst springs of southern France without calling on a drop in the water table below those encountered at the lowest levels of Pleistocene glacio-eustatic fluctuations. The principal karst features around the Mediterranean are probably inherited from the Messinian period (“Salinity crisis”) when sea level dropped dramatically due to the closing of the Straight of Gibraltar and desiccation of the Mediterranean Sea. Important deep karst systems were formed because the regional ground water dropped and the main valleys were entrenched as canyons. Sea level rise during the Pliocene caused sedimentation in the Messinian canyons and water, under a low hydraulic head, entered the upper cave levels.

The powerful submarine spring of Port-Miou is located south of Marseille in a drowned canyon of the Calanques massif. The main water flow comes from a vertical shaft that extends to a depth of more than 147 m bsl. The close shelf margin comprises a submarine karst plateau cut by a deep canyon whose bottom reaches 1,000 m bsl. The canyon ends upstream in a pocket valley without relation to any important continental valley. This canyon was probably excavated by the underground paleoriver of Port-Miou during the Messinian Salinity Crisis. Currently, seawater mixes with karst water at depth. The crisis also affected inland karst aquifers. The famous spring of Fontaine de Vaucluse was explored by a ROV (remote observation vehicle) to a depth of 308 m, 224 m below current sea level. Flutes observed on the wall of the shaft indicate the spring was formerly an air-filled shaft connected to a deep underground river flowing towards a deep valley. Outcroppings and seismic data confirm the presence of deep paleo-valleys filled with Pliocene sediments in the current Rhône and Durance valleys. In the Ardèche, several vauclusian springs may also be related to the Messinian Rhône canyon, located at about 200 m below present sea level. A Pliocene base level rise resulted in horizontal dry cave levels. In the hinterland of Gulf of Lion, the Cévennes karst margin was drained toward the hydrologic window opened by the Messinian erosional surface on the continental shelf.  相似文献   

Grain-size characteristics and climate variability in TMS5e sequence of Tumen section in southern Tengger Desert, northwestern China     

Xiaohao Wen  Baosheng Li  Fengnian Wang  Yanming Zheng  Dongfeng Niu  Yuejin Si  Xianjiao Ou 《中国地理科学(英文版)》2012,22(1):48-62

The TMS5e sequence from the Tumen section,at the southern edge of Tengger Desert in the northwestern China,is synchronous with Marine Isotope Stage 5e(MIS5e).It consists of 16 layers of aeolian dune sands,11 layers of lacustrine loess-like facies,and 5 layers of lacustrine facies.The results of grain-size analysis shows that the palaeo-mobile dune sands,palaeo-fixed to semi-fixed dune sands and loess-like sandy loams are mainly composed of sands,ranging from 70% to 96%;their silt contents ranged from 4% to 20%,and their clay contents ranged from 1% to 5%;the climate under which the aeolian dune sands were deposited is similar to that under which modern mobile dune sands form,which is caused by the dominance of the cold,dry East Asian winter monsoon.In contrast,the lacustrine loess-like facies and lacustrine facies had a lower sand contents than those of the three aeolian dune sands,but have higher silt and clay contents,most of their sand content ranged from 30% to 60%,their silt contents ranged from 35% to 55%,and their clay contents ranged from 6% to 20%.The lacustrine loess-like facies and lacustrine facies formed under the influence of the warm,humid East Asian summer monsoon based on their similarity with modern sediments.The grain-size indicator Mz(mean grain diameter) and the SC/D value in the TMS5e sequence indicate climatic insta-bility at the southern edge of the Tengger Desert during MIS5e,with at least 14 fluctuations between a warm,humid climate and a cold,dry climate,divided into five stages:TMS5e5(139 kyr to 129.3 kyr B.P.),TMS5e4(129.3 kyr to 124 kyr B.P.),TMS5e3(124 kyr to 119.5 kyr B.P.),TMS5e2(119.5 kyr to 116.5 kyr B.P.),and TMS5e1(116.5 kyr to 113.7 kyr B.P.).These correspond roughly to MIS5e5,MIS5e4,MIS5e3,MIS5e2,and MIS5e1,respectively,in the GRIP ice core data.  相似文献   

滨里海盆地东南部S区块下二叠统空谷阶盐岩特征及其对盐上层系油气成藏的影响   总被引：1，自引：0，他引：1  

刘洛夫  尚晓庆  孟江辉  陈治军  宁松华  王萍  李燕 《吉林大学学报(地球科学版)》2012,42(2):304-311

S区块位于滨里海盆地的东南部,油气富集,但是近年来勘探工作突破不大。从地震和地质资料及其油气藏解剖入手,系统研究了本区块盐岩特征及其对盐上层系油气成藏的影响。通过研究认为,本区盐岩的特点为：就整个盆地而言,盐岩的形成模式属于深盆浅水成盐模式;S区块盐构造的形成模式主要属差异负荷模式,其次为断层阻挡的顺层流动模式;盐构造活动具有多期次性;S区块盐岩层厚度总体表现为东南薄、西北厚,即从盆地边缘向盆地中心逐渐加厚;S区块盐窗较为发育,总体上表现为东部盐窗面积大,西部盐窗面积小。盐岩对S区块盐上层系（包括盐上地层和盐间地层）油气成藏的影响很大,盐岩控制了S区块盐上层系圈闭的类型及分布,盐窗的规模对周围的油藏或含油气构造的聚集程度产生影响。对比盐上层系各种成藏要素的时空匹配关系,可以推断本区盐上层系的油气藏共有3次成藏期,分别为三叠纪末期至早侏罗世末期、晚侏罗世末期和晚白垩世至古近纪。  相似文献   

Climate variability in the Salawusu River valley of the Ordos Plateau (Inner Mongolia,China) during Marine Isotope Stage 3   总被引：1，自引：0，他引：1  

Xiaohao Wen  Baosheng Li  Yanming Zheng  David Dian Zhang  Jianping Ye 《第四纪科学杂志》2009,24(1):61-74

Fluctuations in climatic proxies of the Milanggouwan section in the Salawusu River valley of the Ordos Plateau (Inner Mongolia, China) during Marine Isotope stage 3 (MIS 3) coincide well with sedimentary cycles for palaeo‐mobile dune sands alternating with fluvial–lacustrine facies and palaeosols. We compared the palaeo‐mobile dune sands with modern mobile dune sands (products of a cold and dry climate dominated by the East Asian winter monsoon), whereas the fluvial–lacustrine facies and palaeosols were controlled by a wet–warm climate similar to that of the East Asian summer monsoon. The MIS 3 climate of the Salawusu River valley appears to have experienced at least nine wet–warm and ten cold–dry fluctuations, divided into five stages: MIS 3e (58 900–49500 yr BP), MIS 3d (49 500–40 700 yr BP), MIS 3c (40 700–36 900 yr BP), MIS 3b (36 900–27 000 yr BP) and MIS 3a (27 000–22 300 yr BP). The 19 cold–warm climatic fluctuations corresponded roughly to the GRIP and Guliyan records, and with fluctuations in the North Atlantic climate. Notable peaks in the spectral analysis occurred at 19 500 yr, 1020 yr, 640 yr and 500 yr. Our results show that the millennial–centennial climate was closely related to the relative strengths of East Asian monsoons, which are controlled by the North Atlantic thermohaline circulation, and which is also closely linked to the Sun's precession period. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

内蒙古萨拉乌苏河流域第四系更新统上部萨拉乌苏阶基本特征剖析   总被引：3，自引：0，他引：3       下载免费PDF全文

闵隆瑞朱关祥  关友义 《中国地质》2009,36(6):1208-1217

本文概述了对内蒙古萨拉乌苏河流域酒房台剖面更新统上部年代地层-萨拉乌苏阶初步研究的成果.萨拉乌苏阶底部为黄棕色砂层.底界年龄暂定为150 ka.顶界年龄约10 ka,萨拉乌苏阶上部与下部界线年龄约75 ka.萨拉乌苏阶下部以湖沼相沉积为主,夹风、河流堆积物:上部以风成砂为主,夹湖沼相沉积物.150 ka以来该区经受3次水体扩张3次风砂侵入.阶内代表性的古脊椎动物化石,下部是:鄂尔多斯人(即河套人)、主氏水牛、诺氏象、河套大角鹿、哈克图转角羊等:上部是:披毛犀和野驴等.古气候特征是:150～75ka期间,以温湿为主,但中间曾夹有多次气候波动.75～60 ka时期气候转为干冷、多风,60～20 ka间气候明显暖湿,20～10 ka气候又转温.  相似文献   

陆相下白垩统阜新阶重新厘定及其层型剖面     

田树刚  张永生  李子舜  王大宁 《地球学报》2017,38(3):345-358

实测辽宁省建昌县冰沟剖面,选择其为单位层型;开展岩石地层、多门类生物化石和沉积相分析等系统研究,重新厘定陆相阜新阶定义。建昌冰沟组主要由砾岩、砂岩、泥岩和煤层组成,分成三个岩段,第二段为煤系地层。该组为陆相湖盆扇三角洲沉积体系,相序叠置分析属砂砾坝、分流河道、泥沙坪、泥炭沼泽和洪积平原等沉积环境。通过研究以叶肢介为主的化石发生和演变序列,及综合前人研究资料,阜新阶生物地层划分包括叶肢介组合带3个、孢粉化石组合2个、双壳类组合1个和介形虫组合2个。底界层型定在小冰沟村西单一浅湖相地层中,生物标志为叶肢介Orthestheropsis originalis的始现。依据孢粉和介形虫化石资料,阜新阶对比为国际地层表早白垩世巴列姆阶(Barremian)~阿尔必阶(Albian)。  相似文献   

新近系保德阶建阶研究新进展   总被引：12，自引：4，他引：8  

邓涛  王伟铭  岳乐平  张云翔 《地层学杂志》2004,28(1):41-47

根据与古地磁极性年表的对比 ,山西保德冀家沟剖面含保德动物群的保德组上界年龄为 5 .30 Ma,底界年龄不超过 10 Ma,其红黏土的底界为 8Ma,显示该剖面不存在定义的保德阶 11.2 Ma的下界 ,也没有保存保德阶下部的沉积。《国际地层指南》提倡用选择下界的界线层型来确定年代地层单位 ,其上界应该由后续单位的下界来确定。冀家沟剖面显然不具备保德阶的下界 ,但甘肃临夏盆地郭泥沟剖面含三趾马动物群的红黏土之下还有发育的中中新世沉积出露 ,因此 ,后一个地点应存在保德阶的下界 ,并有保德阶最底部的化石和适合于作古地磁分析的沉积物 ,所以临夏盆地是一个有可能建立保德阶下界界线层型的有利地点  相似文献   

“常么阶”沉积相及微相的研究与对比   总被引：10，自引：0，他引：10  

杨湘宁  吴智平 《地层学杂志》1997,21(1):1-19,T002

研究、对比了广西宜山、隆林常么及贵州紫云扁平剖面常么阶的沉积相及微相类型。多元统计分析及碳酸盐岩岩石学的研究表明，这一地区常么阶至少有台前斜坡、台缘生物礁、礁后湖、台缘生物滩、开阔台地、局限台地及蒸发台地等７种沉积相类型及１２种具有不同环境意义的微相类型。古地理位置、水动力条件、循环状况是控制各剖面沉积过程及生物分布的主要环境因素；某些生物（如藻类）的繁盛可以对局部环境进行改造，并进而造成其它生物在种类和数量上的差异。西南地区常么阶代表了马平期与栖霞期之间海退序列的沉积，这一时期的环境变化对有关古生物类群的地理分布产生了重要影响  相似文献   

Silurian Seismites in Hanxia, Yumen, North Qilian Mountains, and Their Tectonic Significance   总被引：5，自引：0，他引：5  

DU Yuansheng  GONG Shuyun  HAN Xin  WANG Jiasheng  GU Songzhuand LIN Wenjiao Faculty of Earth Sciences  China University of Geosciences  Wuhan  Hubei 《《地质学报》英文版》2001,75(4):385-390

The Caledonian erogenic belt of the North Qilian Mountains is an intensely active structure belt. In the process of the Late Caledonian syn-orogeny, the North Qilian-Hexi Corridor area was situated on the tectonic background of a syn-orogenic basin. In response to the orogenic process of the North Qilian Mountains, typical earthquake event deposits-seismites of the Silurian were widely distributed around Hanxia of Yumen City, the Liyuan River of Sunan County and Biandukou of Minle County. In the Hanxia area, where seismites are typically developed, clastic deposits of tidal-flat facies are the background deposits of the Hanxia Formation. The earthquake event deposits are characterized by sandy mudstone veins, synsedimentary microfractures, micro-corrugated laminations and earthquake breccias, which in turn constitute complex seismites, featuring seismic corrugation, shattering and liquefied sandy mudstone veins, auto-clastic breccias and intraclastic parabreccias. The seismites and tidal flat deposits f  相似文献