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1.
丁家寨组的沉答特征表明,自二叠纪的阿赛尔期至萨克马尔期在云南保山地区为一持续的海进过程,其下部含砾层右分成两种成因类型,滨海相成因的下部砾岩层和碎悄流成因的上部角砾将灰岩层。章就有寨组在横向上的展布特点和纵向上岩相变化规律以及其中所含的海相化在石等,对含砾层的各种部川成因说的重要证据（条痕石、落石、三重序列、冰第生物群）提出否定意见。 相似文献
2.
云南西部晚石炭世冰川-海洋相地层的发现 总被引：5，自引：0，他引：5
云南西部石炭系特别发育,自上而下可分为上石炭统卧牛寺组、丁家寨组,下石炭统铺门前组和香山组,中石炭统缺失。丁家寨组下部为滨海相杂砾岩,其中一部分砾石为冰川漂砾,中部属正常冰川-海洋相沉积,含冷水动物群化石,冰川砾石面上具擦痕、压裂和凹坑等;上部含(竹蜒)科化石,气候已由寒冷变为温暖。 相似文献
3.
云南施甸丁家寨组沉积环境及下部含砾层的成因探讨 总被引：3，自引：0，他引：3
《地层学杂志》1990,(1)
<正> 滇西保山地区在大地构造位置上介于怒江断裂带和澜沧江断裂带之间。段新华等(1983)发现下冈瓦纳相地层及古生物,对本区晚古生代古生物、地层和沉积相的研究为地质工作者所关注,关于上石炭统丁家寨组下部含砾层的成因解释是人们感兴趣的课题之一。王义昭(1983)、曹仁关(1986)等提出含砾层属于冰川—海洋相成因,把它和西藏曲 相似文献
4.
通过对保山地块北部西邑地区下石炭统香山组和下二叠统丁家寨组详细的野外剖面实测与钻孔编录,并结合层序地层学、沉积相以及碳氧同位素分析结果认为,下石炭统香山组自下向上可分为三个岩性段,分别对应台前斜坡下部、台前斜坡上部、碳酸盐岩台地三种沉积环境。下二叠统丁家寨组为滨岸冰水沉积,下部为冰碛含砾钙质杂砂岩,发育落石构造。下石炭统香山组δ13CPDB值自下而上逐渐升高,环境可能较稳定,有机质埋藏增加。综合前人古地磁、生物区系对比、大地构造学等研究成果认为早石炭世保山地块较稳定,仍属冈瓦纳大陆北缘。丁家寨组冰碛含砾钙质杂砂岩结束后δ13CPDB值出现强烈负偏,与研究区冰期结束、早二叠世初次温度上升、大量玄武岩喷发等时限高度一致,共同说明了保山地块在早二叠世开始从冈瓦纳大陆北缘裂解出来,并开始向北漂移。该项研究的开展为探讨Submasu地块晚古生代的古海洋、古地理和气候演化具有重要意义,为全球同时期碳氧同位素数据库提供了新资料。 相似文献
5.
保山地块下二叠统丁家寨组碳同位素特征 总被引：1，自引：1，他引：0
对保山地块的下二叠统丁家寨组碳酸盐岩、含砾钙质杂砂岩及其上、下层位的碳酸盐岩进行了野外剖面实测、钻孔编录和碳、氧同位素分析测试,发现该地区丁家寨组碳同位素表现出一定的变化规律。丁家寨组之下和之上的碳酸盐岩δ13C值偏大(均为正值),而丁家寨组δ13C值出现了一至多次负偏移。珊瑚化石和苔藓虫化石分别在铺门前组和丁家寨组中被发现,为其时代的限定提供了新依据。通过与全球其它地区同期碳氧同位素分布的投图对比,发现该时期碳、氧同位素数据因受到冰川的影响而表现出具有较强的线性相关性,这些样品受到了成岩作用的影响。δ13C负偏移可能与冰期低水位期沉积和成岩过程中近地表的暴露有关。卧牛寺玄武岩大面积喷发引起的各种效应,包括CO2含量的升高、全球变暖、风化作用的加强、陆源碎屑输入的增加等多种因素,协同冰川作用共同影响了丁家寨组海洋无机碳同位素的变化。 相似文献
6.
在精细测量和详细观察新疆塔尔朗沟剖面二叠系露头的基础上,系统研究了中二叠统大河沿组与塔尔朗组扇三角洲相内陆源碎屑与碳酸盐组分的混合沉积特征。结果表明:大河沿组以扇三角洲平原分流河道沉积为主,其下部主要发育棕红色含粗砾中砾岩,碳酸盐组分不发育;上部主要发育棕红色含中砾细砾岩,夹若干层条带状分布的砾质泥晶灰岩。塔尔朗组底部自下而上发育扇三角洲前缘水下分流河道与水下分流间湾。水下分流河道为底凸顶平的砂砾岩体,下部发育灰绿色含中砾细砾岩夹含砾泥晶灰岩,灰岩呈断续条带状分布,横向延伸距离较小;上部发育灰绿色细砾岩夹含砾泥晶灰岩,灰岩在横向上的延伸距离较大。水下分流间湾以灰绿色泥岩和层状含砂泥晶灰岩为主,灰岩在横向上分布较稳定。结合前人在研究区中二叠世古气候、沉积环境等方面的认识,进一步建立了扇三角洲混合沉积模式。 相似文献
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8.
该文通过对哀牢山构造带西侧云南省南涧地区下白垩统南新组砾岩层的砾性、砾度、砾态和砾向等的详细研究与分
析,结合盆地基岩地层特点和周边构造带的岩性组合特征,发现南新组砾岩总体上具有砾石成分复杂、分选性较差、磨圆程
度中等-较好（次圆状-圆状）、风化程度较低等特征;探讨了砾岩层本身的性质、物质来源,以及砾石沉积时盆地的水动力条
件、气候环境、古地貌特征和构造条件。认为南新组砾岩层为半干旱-干旱古气候条件下的一套冲积扇-辫状河相粗碎屑沉
积,具有快速堆积的特点;砾岩层沉积前砾石遭受了较强的物理化学作用。根据盆地基岩及周边地层岩性特点和砾石扁平面
倾向统计,砾石的主要来源是盆地内部的基底地层及其东缘的哀牢山构造带。 相似文献
9.
滇西亲冈瓦纳微古植物的发现及其地质意义 总被引：7，自引：1，他引：6
本文首次报道滇西保山丁家寨组孢子花粉４０属５５种,其中新种Ｐｌｉｃａｔｉｐｏｌｅｎｉｔｅｓｂａｏｓｈａｎｅｎｓｉｓ１个。丁家寨组的孢子花粉组合是一个以冈瓦纳植物地理区分子为主,兼有少量华夏植物地理区和其它植物地理区分子。丁家寨组的Ｐａｒａｓａｃｉｔｅｓｄｉｓｔｉｎｃｔｕｓ－Ｍｉｃｒｏｂａｃｕｌｉｓｐｏｒａｆｅｎｔｕｌａ（ＤＦ）孢子带可与冈瓦纳植物地理区Ｐａｒａｓａｃｉｔｅｓ孢子带比较,时代为阿舍尔阶（Ａｓｅｌｉａｎ）萨克马尔阶（Ｓａｋｍａｒｉａｎ）。丁家寨组的微古植物研究不仅有重要的地层学和古生物学意义,而且对研究冈瓦纳大陆与欧亚大陆之间的关系有着十分重要的意义。 相似文献
10.
雪峰古陆边缘石岩统为一套滨浅海碳酸盐岩和碎屑岩沉积。下部黄龙组为白云岩，灰岩和砾岩及少量硝岩互层，上部船山组为灰岩，白云质与砂岩及少量砂岩互层，船山组含Ｔｒｉｔｉｃｉｅｓ带和Ｐｓｅｎｄｏｓｃｈｗａｇｅｎｉｎａ带。整个上石炭统碎屑岩和碳酸盐岩交替出现，属海水浅的滨海陆脊滩相至局限台地相。 相似文献
11.
In Permian times the Baoshan Block of western Yunnan, southwest China formed the eastern part of the Cimmerian Continent. Most biogeographical and sedimentological data indicate that the Early Permian Dingjiazhai Formation formed on the block under conditions strongly influenced by the Permo-Carboniferous glaciation. After Early Permian rifting, with post-glaciation climatic amelioration, and as the Baoshan Block drifted northwards to approach South China and Indochina, faunal elements characteristic of Gondwana affinity decreased, while those of Cathaysian affinity increased. Finally, Late Permian faunas are characterized by exclusively Cathaysian elements. This shift of marine provinciality becomes an important indicator in understanding the Permian paleoclimatic evolution of the region. This research investigated the composition of carbonate grain associations and the early diagenetic features of limestones from the upper part of the Dingjiazhai Formation, and from the overlying Yongde and Shazipo formations. A sharp distinction in petrological and diagenetic features is recognized between the Dingjiazhai Formation and the two overlying formations. The Dingjiazhai carbonates are characterized by the bryonoderm (bryozoan-echinoderm)-extended facies of the heterozoan association, with no non-skeletal grains. Because early diagenetic cement was rarely formed, the Dingjiazhai carbonates experienced strong diagenetic compaction. In contrast, the Yongde and Shazipo carbonates show a chloroforam facies of photozoan association, with the common occurrence of non-skeletal grains. These carbonates were well cemented during early diagenetic processes. From comparison with Permian cool-water carbonates from northern Pangea and Tasmania, Australia, the Dingjiazhai carbonates are interpreted as deposits of warm-temperate conditions, while the overlying carbonates are considered to be deposits of subtropical or tropical conditions. This climatic interpretation, based on the petrographic features of the Permian carbonates, agrees well with existing biogeographical data from the region. 相似文献
12.
滇西亲冈瓦纳相生物群特征及地层时代的重新厘定 总被引：14，自引：1，他引：14
滇西保山地区丁家寨组及其上覆卧牛寺组,前人根据其中(虫筳)类化石定为上石炭统(马平阶),沿用至今。笔者在该区多门类化石中,见到不同时代的化石混积在一起,包括异地再沉积的早石炭世腕足类Syringothyris,石炭纪的(虫筳)类、珊瑚等。原地埋藏的腕足类有Steriochia litostyla等,并保存有完好的壳刺。厘定后的时代为Sakmarian晚期至Artinskian,它可与西藏的冈瓦纳相地层及生物群进行对比。 滇西腾冲地区空树河组及其上覆的岩子坡组,前人因其含(虫筳)Triticites,Quasifusulina等也定为上石炭统。实际上,空树河组中、上部的多门类化石(包括腕足类、苔藓虫、单体珊瑚和微古植物等),与丁家寨组相似,具有强烈的二叠纪面貌,与冈瓦纳相更为接近。厘定空树河组时代为Sakmarian—Chihsian,它与西藏的相应地层可以很好地进行对比。 相似文献
13.
Lithologic Boundaries in Permian Post-glacial Sediments of the Gondwana-affinity Regions of China: Typical Sections, Age Range and Correlation 总被引：1，自引：0，他引：1
In Southwest China, Gondwana-affinity Permo-Carboniferous deposits are known to occur in the Northern Himalayas, the Lhasa Block and the South Qiangtang Block, the Baoshan Block and the Tengchong Bock. The three-fold clastic successions, namely diamictite–pebbly mudstone–dark mudstone and shale are commonly interpreted as representing deposits of glacial–deglacial–post-glacial periods in marine environments. Deposits, for example, the Dingjiazhai Formation in the Baoshan Block, the Kongshuhe Formation in the Tengchong Block, the Yongzhu Group and the Poindo Group in the Lhasa Block, are all succeeded by carbonate deposits. This marks a significant change from post-glacial clastic environment to a carbonate environment. Available paleontological data show that the change from post-glacial clastic environment to carbonate environment took place in the Baoshan, Tengchong and Lhasa Block at the beginning of the Artinskian. The carbonate environment in the Baoshan Block was spoiled by the eruption of the Woniusi Basalts, and in the Xainza area of the Lhasa Block was shortly replaced by clastic environment until the Kungurian. In the northern Himalayas limestones began to occur in the Late Permian in a fluctuating manner. 相似文献
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Flat-pebble conglomerate: its multiple origins and relationship to metre-scale depositional cycles 总被引：8，自引：0，他引：8
Paul M. Myrow Lauren Tice Bonny Archuleta† Bryn Clark‡ John F. Taylor§ Robert L. Ripperdan¶ 《Sedimentology》2004,51(5):973-996
Carbonate flat‐pebble conglomerate is an important component of Precambrian to lower Palaeozoic strata, but its origins remain enigmatic. The Upper Cambrian to Lower Ordovician strata of the Snowy Range Formation in northern Wyoming and southern Montana contain abundant flat‐pebble conglomerate beds in shallow‐water cyclic and non‐cyclic strata. Several origins of flat‐pebble conglomerate are inferred for these strata. In one case, all stages of development of flat‐pebble conglomerate are captured within storm‐dominated shoreface deposits of hummocky cross‐stratified (HCS) fine carbonate grainstone. A variety of synsedimentary deformation structures records the transition from mildly deformed in situ stratification to buckled beds of partially disarticulated bedding to fully developed flat‐pebble conglomerate. These features resulted from failure of a shoreface and subsequent brittle and ductile deformation of compacted to early cemented deposits. Failure was induced by either storm or seismic waves, and many beds failed along discrete slide scar surfaces. Centimetre‐scale laminae within thick amalgamated HCS beds were planes of weakness that led to the development of platy clasts within partly disarticulated and rotated bedding of the buckled beds. In some cases, buckled masses accelerated downslope until they exceeded their internal friction, completely disarticulated into clasts and transformed into a mass flow of individual cm‐ to dm‐scale clasts. This transition was accompanied by the addition of sand‐sized echinoderm‐rich debris from local sources, which slightly lowered friction by reducing clast–clast interactions. The resulting dominantly horizontal clast orientations suggest transport by dense, viscous flow dominated by laminar shear. These flows generally came to rest on the lower shoreface, although in some cases they continued a limited distance beyond fairweather wave base and were interbedded with shale and grainstone beds. The clasts in these beds show no evidence of extensive reworking (i.e. not well rounded) or condensation (i.e. no rinds or coatings). A second type of flat‐pebble conglomerate bed occurs at the top of upward‐coarsening, metre‐scale cycles. The flat‐pebble conglomerate beds cap these shoaling cycles and represent either lowstand deposits or, in some cases, may represent transgressive lags. The clasts are well rounded, display borings and have iron‐rich coatings. The matrix to these beds locally includes glauconite. These beds were considerably reworked and represent condensed deposits. Thrombolites occur above the flat‐pebble beds and record microbial growth before initial transgression at the cycle boundaries. A third type of flat‐pebble conglomerate bed occurs within unusual metre‐scale, shale‐dominated, asymmetric, subaqueous cycles in Shoshone Canyon, Wyoming. Flat‐pebble beds in these cycles consist solely of clasts of carbonate nodules identical to those that are in situ within underlying shale beds. These deeper water cycles can be interpreted as either upward‐shoaling or ‐deepening cycles. The flat‐pebble conglomerate beds record winnowing and reworking of shale and carbonate nodules to lags, during either lowstand or the first stages of transgression. 相似文献
16.
JI Zhansheng YAO Jianxin JIN Xiaochi YANG Xiangning WANG Yizhao YANG Hailin WU Guichun Institute of Geology Chinese Academy of Geological Sciences Baiwangzhuang Ro Beijing Department of Earth Sciences Nanjing University Nanjing Jiangsu Geological Survey of Yunnan Yujiang Ro Yuxi Yunnan 《《地质学报》英文版》2004,78(6):1179-1184
The Rabeignathus bucaramangus fauna was recently found from the limestone beds of the top part of the elastics-dominated Dingjiazhai Formation in the Aluotian section, southern Baoshan Block, western Yunnan. With Rabeignathus bucaramangus as the dominant species, this fauna includes Rabeignathus bucaramangus (Rabe), Homeoiranognathus huecoensis (Ritter), Sweetognathus inomatus Ritter, Sweetognathus whitei (Rhodes), Mesogondolella cf. bisselli (Clark and Behnken) and a few of ramiform elements. The characteristies of the fauna suggest that it can be correlated with the upper part of the Sweetognathus whitei Zone and assigned to the Middle Artinskian. 相似文献
17.
大巩山西蝈堆组蚌埠期褶皱可利用含白云质大理岩透镜体的蛇纹岩作为标志层来恢复,推测其为轴面倒向北的紧密同斜褶皱,S0近南北向,枢纽西倾,地层由东向西变新。 相似文献
18.
落雪组是主要含矿层位。底部过渡层以斑铜矿、黄铜矿为主,中部含较多铜矿结核,顶部发育网脉状铜矿。具层控性,铜矿的规模与地层厚度有一定的关系。 相似文献