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1.
杨春惠 《科学技术与工程》2012,12(29):7493-7499
乌伦古坳陷东部地域开阔,地表起伏较大,经历了多期构造活动改造,形成了北西-南东向构造格局。结合乌伦古坳陷东部的构造格局和沉积环境发育特点,采用均方根振幅属性对其进行有利储层预测。通过对该地区二维地震资料层序地层均方根振幅的研究,表明不同沉积时期、不同构造部位均方根振幅的平面分布随构造格局和沉积环境的变化而变化。红岩断阶带和乌伦古凹陷南缘深大断裂上盘为断背斜或断鼻构造圈闭。红岩断阶带下盘为岩性上倾带,以河流、(扇)三角洲沉积为主,岩性组合以砂泥互层为主,含砂率高,均方根振幅表现为高值,为油气聚集的有利目标区带。索索泉凹陷处于挤压隆升背景下的沉降部分,以湖相沉积为主,均方根振幅表现为低值,不利于形成有利储层。  相似文献   

2.
The Fengzhou loess section is very typical in the Qinling Mountains. The section, about 82 m thick and underlain by the Neogene red clay, consists of 33 layers of loess and 33 layers of paleosol. The section covers Brunnes normal polarity zone and Matuyama reversed polarity zone, and the B/M boundary is located in the middle of L8. Matuyama reversed polarity zone records Jaramillo, Olduvai and Reunion normal polarity subchrons. The boundary between Matuyama reversed polarity zone and Gauss normal polarity zone (M/Ga) appears in the lithological boundary between loess and the Neogene red clay. Loess accumulation in Fengzhou started before 2.48 Ma. The magnetic susceptibility curve indicates 33 cold-dry and humid-warm cycles of paleoclimatic variation in the Qinling Mountains during the last 2.48 Ma. The above climatic fluctuation may be well compared with that of the oxygen isotopic records from deep-sea deposits.  相似文献   

3.
The faunal ecological type and sequence in the Tertiary red clay indicate that Hipparion fauna during the period 7.4-6.1 Ma in the middle reaches of the Yellow River is composed mainly of dorcadoides and mixed types. This represents semiarid veld environment with small fluctuation. The fossil assemblages characterized by the abundance of gaudryi types and even the occurrence of some Hominoid and Chalicotherium indicate an obviously warm and humid period since 5.3 Ma. The fossil assemblages during 3.4 Ma show the typical steppe fauna representing dry climate. It is indicated by the changes of ecological sequence that the climatic conditions in Pliocene are drier than that in late Miocene. The clay-skin content of red clay, which has a synchronous change with faunal features, is a rather good replacing palaeoclimatic index.  相似文献   

4.
The faunal ecological type and sequence in the Tertiary red clay indicate that Hipparion fauna during the period 7.4–6.1 Ma in the middle reaches of the Yellow River is composed mainly of dorcadoides and mixed types. This represents semiarid veld environment with small fluctuation. The fossil assemblages characterized by the abundance of gaudryi types and even the occurrence of some Hominoid and Chalicotherium indicate an obviously warm and humi period since 5.3 Ma. The fossil assemblages during 3.4 Ma show the typical steppe fauna representing dry climate. It is indicated by the changes of ecological sequence that the climatic conditions in Pliocene are drier than that in late Miocene. The clay-skin content of red clay, which has a synchronous change with faunal features, is a rather good replacing palaeoclimatic index.  相似文献   

5.
The results of paleogeomagnetics and geochemistry of the coral reef in well Nanyong 2 of Nansha Islands showed that the bottom of the black sedimentary interlayer corresponds to the conversion boundary line between Brunhes Postive Polarity and Matuyama Reversed Polarity (B/M) and the cold/warm (19/20) climatic conversion bounds on δ18O curve, 0.78 Ma ago; and the red sedimentary interlayer corresponds to the ReunionⅠpolarity excursion (reversion) of the geomagnetic field, 2.01—2.04 Ma ago. Comparing with the normal light-coloured coral reef rock, the magnetic susceptibility (c), residual magnetization intensity (Mr) and the content of MnO and Fe2O3 of the black sedimentary layer appeared obviously positive abnormity. The magnetic susceptibility (c), residual magnetization intensity (Mr) and the content of Fe2O3 of the red sedimentary layer also appeared positive abnormity. Combining with the analyzing results of paleontology, we hold that this pair of special and typical sedimentary interlayers was relative to the sudden change of paleoclimate, i.e. the global climatic change and its incidental polarity reversal of the geomagnetic field directly affected the living environment of the paleontological species as well as the dispersion and enrichment of some chemical elements, especially the elements sensitive to redox such as Fe and Mn. For example, the elements Fe and Mn concentrated in the glacial period would be largely oxidized and diluted when the climate warmed up suddenly, and the originally oxidized high valence Fe would be condensed again when the climate cooled suddenly. This is possibly one of the important reasons of appearing and disappearing of the red and black sedimentary events of coral reef in well Nanyong 2.  相似文献   

6.
逆冲活动对准南前陆盆地层序构成的影响及意义   总被引:1,自引:0,他引:1  
新近纪准噶尔盆地南缘是在北天山强烈逆冲构造背景下发育的前陆盆地.其新近系沙湾组-塔西河组可划分为1个二级层序,2个三级层序,均由角度不整合、平行不整合或沉积环境转换面所分隔.整个二级层序的沉积构成反映了从前陆逆冲挠曲沉降到回弹隆升的演化过程,层序1沉积构成明显受逆冲构造活动控制,而回弹隆起影响了构造相对宁静期的层序2内部沉积构成.新近纪逆冲构造活动阶段的内部演化,制约了同期的冲积扇-扇三角洲沉积体系.受逆冲构造活动影响,层序1(沙湾组)扇三角洲砂体不断向盆地推进,侧向连片,垂向上相互叠置形成厚度可观的储集体,其下伏前期深湖相烃源岩,离生烃中心近,上覆层序2(塔西河组)发育的大量细粒沉积物作为良好的盖层,易形成大型油气田.  相似文献   

7.
报道了在山西襄汾赵店采砂场,黄土下部砂层中发现了哺乳动物群化石,并对化石出土层位的时代和古环境进行了分析.在赵店的动物群化石中除最后鬣狗和虎外,基本上与丁村动物群相同,出土层位也与丁村组相似.从化石出土层位上覆黄土古土壤序列分析,化石层与S1古土壤发育时代相当,其时代上限为距今7.5万年,当属末次间冰期,气候相对温暖湿润.  相似文献   

8.
Late Permian magnetostratigraphy and its global correlation   总被引:4,自引:0,他引:4  
A calibration among magnetic polarity sequence, biostratigraphy zonation and isotopic age reveals that the boundary between the Carboniferous-Permian reversed Polarity Superzone and Permian-Triassic Mixed Polarity Superzone occurs at the top of the Wordian Stage of the Guadalupian Series and is dated as 265 Ma. The Late Permian magnetic polarity sequence integrates four polarity zones, corresponding to the Upper Guadalupian Series, the Wuchiapingian Stage, and the Lower and the Upper Changhsingian Stage of the Lopingian Series. This reference magnetostratigraphy polarity sequence may serve as a useful guide to the chronostratigraphic correlation of Late Permian strata across major biogeographic and facies barriers.  相似文献   

9.
The Tertiary deposits of the Yongdeng section, the Lanzhou Basin were studied by means of magnetostrati-graphy. The magnetostratigraphic sequences from Paleocene to Miocene were established, and the time scale for the corresponding stratigraphy and mammalian faunas was also established by referring to their correlation to the GPTS of BKSA95 (The geomagnetic polarity time scale which was thoroughly revised and updated by Berggreen et al. in 1995). In the end the paleoenvironmental records and their relationship with the uplifting of the Tibetan Plateau were discussed. The results are as follows. The top boundary of the Xiliugou Formation is dated to be 51 Ma, i.e. Eocene. TheYehucheng Formation covers the time span of 51-31.5 Ma, i.e. from late Early Eocene to early Early Oligocene. The Xianshuihe Formation covers the time span of 31.5-15 Ma, i.e. from Early Oligocene to Middle Miocene. The lower member of the Xianshuihe Formation spans from 31.5 to 20.0 Ma, i.e. from Early Oligocene to early Early Miocene. The middle member is from 20.0 to 16.5 Ma, i.e. in the middle Early Miocene.  相似文献   

10.
吐哈盆地七泉湖构造带油气成藏史   总被引:1,自引:0,他引:1  
构造演化史研究表明,七泉湖构造带从燕山期开始发育,第三系地层沉积前已具圈闭雏形,继承性的古构造背景是油气运移的有利通道.逆掩断裂带下盘的侏罗系水西沟群烃源岩成熟较晚,在晚第三纪大量生烃.七泉湖构造带流体包裹体特征明显,主要发育一期流体包裹体,烃类包裹体及伴生的盐水包裹体均发育在切割碎裂石英和胶结物的裂隙中,储层中的包裹体均一温度分布都只有一个主峰温度区间.结合地质背景、构造演化史、烃源岩演化史、油气藏饱和压力资料确定了七泉湖-玉果油田侏罗系油藏的成藏时间为晚第三纪.  相似文献   

11.
本文采用尹赞勋提出的地球历史发展的两大阶段:天文时期与地质时期,并同意废弃隐生宙与显生宙。本文着重讨论了生物的发展,从无机到有机,到蛋白质,到细胞,到后生动物的阶段性。建议地质时期代的划分,根据生物发展阶段特征,前寒武纪划分为无生代、隐生代、始生代与原生代。另把古生代下限延至900Ma,包括震旦纪。小壳动物应归属震旦纪,而不是寒武纪。  相似文献   

12.
Among the most important faunas in the Late Cenozoic, the Gigantopithecus faunas have received a good deal of attention. The Gigantopithecus fauna recently discovered in Sanhe Cave consists of more than 80 mammal species, including cf. Hominidae, Pongo sp., Hylobates sp., Sinomastodon yangziensis, Stegodon preorientalis, Cervavitus fenqii, Dicoryphochoerus ultimus and Sus xiaozhu. It is the southernmost Gigantopithecus fauna found so far in China. Its geological age is estimated to be Early Pleistocene based on the fauna and stratigraphic correlation. The significant increase in the estimated body sizes of Ailuropoda, Gigantopithecus and Tapirus shows that the Sanhe fauna is middle Early Pleistocene, later than those from Wushan and Liucheng (early Early Pleistocene). Paleomagnetic dating of the fossil-bearing strata in Sanhe Cave gives an age of approximately 1.2 Ma. The fauna is characterized by tropical-subtropical forest types, including Pongo sp., Tupaia sp., Ia sp., Typhlomys intermedius, etc., and it lacks Palaearctic types. It is a typical tropical forest fauna, suggesting an environment with a lush forest and a warm and humid climate. The discovery of the Sanhe Gigantopithecus fauna is significant for establishing the chronological stages of the Gigantopithecus faunas in China, and for discussing their origin, evolution and dynamics. Supported by Key Knowledge Innovation Project of the Chinese Academy of Sciences (KZCX2-YW-106) and National Basic Research Program of China (Grant No. 2006CB806400)  相似文献   

13.
土壤动物是陆地生态系统的重要组成部分,为探讨不同土地利用类型土壤动物对土壤氮矿化过程的影响,以苏北沿海地区3种土地利用方式(杨树人工林、农田、杨农复合林)为研究对象,通过设置不同实验处理(对照、撒噻唑磷驱除土壤线虫、撒萘驱除所有土壤动物),采用顶盖埋管法测定土壤矿质氮的含量,分析了土壤动物对有机氮矿化速率的影响。结果表明:①3种土地利用类型驱除土壤线虫和驱除所有土壤动物处理的土壤NO-3-N 和总无机氮(TMN)含量均显著低于对照(P<0.05),说明土壤线虫和土壤动物的存在能显著提高土壤中NO-3-N和总无机氮的含量; 而NH+4-N含量变化不明显。②土地利用类型和土壤动物类群数量的改变会影响土壤净氮矿化速率; 0~10 cm土层,对照处理土壤净氮矿化速率从大到小表现为农田>杨树林>杨农复合林,驱除线虫和驱除所有土壤动物处理下均表现为杨农复合林>农田>杨树林; 各处理≥10~25 cm土层动物变化不显著。且0~10 cm对照和驱除线虫处理,杨树林与农田间土壤净氮矿化速率差异显著(P<0.05,P<0.01)。驱除线虫和驱除所有土壤动物均能降低土壤净氮矿化速率(P<0.05)。③驱除所有土壤动物处理的土壤微生物量氮的含量极显著低于对照(P<0.01),表明驱除土壤动物对土壤微生物有极显著的影响。  相似文献   

14.
鄂尔多斯盆地大牛地气田马五6-10亚段沉积微相高频变化,分布特征尚不明确,严重制约了天然气勘探与开发。综合利用岩心、薄片、测井及野外露头等资料,详细分析了该地区马五6-10亚段碳酸盐岩岩石类型及测井响应特征,划分了4种沉积微相,进一步分析了该地区马五6-10亚段高频沉积相演化特征。马五期海平面整体呈下降趋势,发育局限台地亚相,云坪、膏云坪、灰云坪微相在空间上彼此相邻,纵向上相互叠置,随着海平面变化相互转化。马五10、马五8、马五72、马五61亚段主要发育膏云坪和云坪微相,马五9亚段主要发育云坪和灰云坪微相,马五71、马五62亚段主要发育膏云坪、云坪及灰云坪微相,马五63亚段则由西向东依次发育膏云坪、云坪、灰云坪、云灰坪微相。研究区海平面升降控制了沉积亚相的演化,更为高频的次级海平面变化控制着沉积微相快速变化。鄂尔多斯盆地大牛地气田马五6-10亚段沉积相高频演化特征研究,将有力支撑大牛地气田马家沟组深部天然气资源的开发动用,同时为大牛地气田马家沟组沉积模式研究提供依据。  相似文献   

15.
2007年1~4月,对韶关市郊不同类型坡地的土壤动物进行采集调查,共获得动物标本663只,隶属3门10纲19目,其中蜱螨目和弹尾目是优势类群,盲蛛目、鞘翅目、膜翅目、颤蚓目为常见种类;稀有种类因植被的不同各有差异,竹林动物种类与数量比较多.土壤动物垂直分层分布现象比较明显,随土层的加深而减少;植被类型是影响土壤动物群落结构和多样性的主要生态因子.  相似文献   

16.
通过详细的野外调查,发现陕西神木邱家鄢地区存在一古河流阶地,根据该阶地上覆晚第三系红粘土推测该阶地为晚第三纪形成的。对该阶地上覆地层进行调查表明,该区晚第三纪红粘土之下存在约53米的风成砂层和河流相砂层。对红粘土和粉砂层进行古地磁测年样品的采集和测试。古地磁研究结果表明,该剖面底部的年代约在6.8 Ma左右,而红粘土与粉砂层之间的界限在6.27 Ma。根据深度-年代之间的关系,推算得出底部粉砂层的沉积速率比上部红粘土的沉积速率要快10倍以上,结合区域气候变化和构造运动历史的研究,邱家鄢剖面在(6.8-6.27)Ma之间快速沉积粉砂层的来源可能是中游黄河的河漫滩,指示了山陕峡谷段南北流向的古黄河可能在中新世晚期的6.8 Ma以前已经在该区出现。  相似文献   

17.
A SHRIMP U-Pb zircon geochronology study of the tuff at the bottom of the Lower Cambrian Niutitang Formation at Songlin, Zunyi, South China yielded a mean ^206Pb/^238U age of 518±5 Ma. It is significantly younger than the Re-Os ages of 537--542 Ma for the overlying polymetallic Ni-Mo-PGE-rich layer in the basal Niutitang Formation at Songlin, suggesting that the Re-Os ages might represent that of the original magma chamber for the Ni-Mo-PGE-rich layer rather than the formation age of the strata. The intra-basinal stratigraphic correlation also implies that the absolute age of the Chengjiang biota should be younger than 518±5 Ma. Our new result, together with the SHRIMP U-Pb zircon age for the K-bentonite in the Zhongyicun member of the Zhujiaqing Formation at the Meishucun section, Yunnan Province, provides a temporal constraint for the Lower Cambrian of the Yangtze Platform in South China.  相似文献   

18.
有机发光器件ITO阳极表面能的研究   总被引:3,自引:0,他引:3  
在测量TIO接触角的基础上,应用调和平均法计算了不同表面处理ITO阳极的表面能和极性度。结果表明:ITO的表面能和极性度随其表面处理方式而变化,并且表面能的变化主要来源于极性分量的增减;经氧等离子体处理后的ITO具有最大的表面能和极性度,这一结果对于优化ITO阳极/有机层界面的性质,改善有机发光器件的性能具有重要意义。  相似文献   

19.
盐构造剖面的分层合并复原方法及应用   总被引:5,自引:0,他引:5  
提出了盐构造区复原剖面制作的一种新方法——分层合并复原法,即将盐上、盐下和盐层分别复原,然后合并.与传统盐构造区复原剖面制作方法相比,该方法不需要进行均衡调整,减少了均衡调整计算中的误差,更符合实际变形情况.既可用于挤压区,也可用于伸展区;既可用于盐下复杂变形区,也可用于盐下简单变形区.理想情况下,还可通过对比两期复原剖面盐的面积,估算在此变形期间流入或流出剖面盐的面积.利用分层复原法制作的库车坳陷盐构造复原剖面反映出库车坳陷盐构造的发育经历了盐层及盐上层沉积期(65~23.3Ma)、盐构造初动期(23.3~1.64Ma)和盐构造定型期(1.64Ma以来)等3个发展阶段.  相似文献   

20.
研究了二叠纪未生物大灭绝事件后双壳类的首次辐射,辐射的代表是贵州青岩地区中三叠世Anisian晚期的青岩生物群,共50余属100余种,归在5亚纲10目18超科32科。以往通常认为双壳类的辐射发生在晚三叠世,以阿尔卑斯地区圣·卡息安生物群为最早代表;但根据研究,大灭绝后双壳类的首次辐射时代比以往认为的圣·卡息安生物群早约1000万年。  相似文献   

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