北京西郊下苇甸剖面寒武系崮山组叠层石生物丘的沉积组构   总被引：10，自引：2，他引：8  

梅冥相  郭荣涛  胡媛 《岩石学报》2011,27(8):2473-2486

北京西郊下苇甸剖面的崮山组,属于寒武系第三统顶部,自下而上从陆棚相泥灰岩向上变浅至鲕粒滩相灰岩,组成一个淹没不整合型三级沉积层序。在该组上部的一层块状鲕粒滩相颗粒灰岩中,发育串珠状分布的、可以归为叠层石生物丘的穹窿状构造。这些叠层石生物丘,典型的地势隆起和突变的边界代表了明显的早期石化作用特征。叠层石生物丘中的柱状叠层石,为典型的泥晶相叠层石,其内部除了黏结较多的三叶虫生物碎屑外,还不均匀地分布着放射-纤维状方解石(或文石？)组成的底栖鲕粒。这些底栖鲕粒,以其较小的粒径、多样的类型、平滑但不连续的鲕粒圈层以及外部边缘的泥晶套等特征,明显区别于宿主岩石中的颗粒滩相悬浮鲕粒,而且表现出较为明显的与微生物活动相关的微组构。鉴于叠层石是典型的微生物席建造物,该叠层石生物丘特别的宏观和微观沉积组构还可以进一步将其归为较为典型的"微生物礁",从而成为研究中奥陶生物大辐射事件之前贫乏骨骼的浅海环境的沉积作用样式、以及更加深入理解这一特殊时期的微生物造礁作用特征提供了一个较为典型的实例。  相似文献   

Carbon and strontium isotopes and global correlation of Cambrian Series 2-Series 3 carbonate rocks in the Keping area of the northwestern Tarim Basin, NW China     

Xiaolin WangWenxuan Hu  Suping YaoQi Chen  Xiaomin Xie 《Marine and Petroleum Geology》2011,28(5):992-1002

One hundred and ten carbon and nineteen strontium isotopic values of outcropping Cambrian Series 2 and Series 3 carbonate rocks in the Penglaiba section of the Keping area were analyzed. Effective isotopic data with little influence of diagenesis were used to address the global correlation. The δ¹³C values exhibit two major positive excursions (peaking at 3.1‰ and 3.3‰) and three major negative excursions (peaking at −3.0‰, −4.2‰ and −3.2‰). The carbon isotope excursions (peaking at −3.0‰ and −4.2‰) across the Cambrian Series 2-Series 3 boundary show good correlations with similar variations reported in Siberia, Laurentia, North China and South China. In contrast, the other three carbon isotope excursions (peaking at 3.1‰, 3.3‰ and −3.2‰) do not have a fairly good global correlation because of the lack of biostratigraphic data. With respect to the ⁸⁷Sr/⁸⁶Sr ratios, they show good correlation with those reported for Laurentia, and further support the global δ¹³C comparison. On the basis of these new data, it is showed that the combination of δ¹³C curves and ⁸⁷Sr/⁸⁶Sr variations serves as a powerful tool for correlation and subdivision of Cambrian strata in the Tarim Basin of northwest China, and provides new data for global correlation.  相似文献   

标准海水研究现状及其应用     

赵卓英  田孟安  孙浩  胡波 《海洋通报》2011,30(3):283-286

标准海水作为海水盐度量值的标准物质,广泛用于检定和校准海水盐度测量仪器和装置.主要介绍两种标准物质-中国-级标准海水和中国系列标准海水,系统介绍我国现阶段标准海水的制备,封装工艺,保存方法,并阐述其在使用过程中的注意事项.  相似文献   

Bio-optical characteristics of Cariaco Basin (Caribbean Sea) waters     

Laura Lorenzoni  Chuanmin HuRamón Varela  Glenda AriasLaurencia Guzmán  Frank Muller-Karger 《Continental Shelf Research》2011,31(6):582-593

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Occurrence and significance of Ischadites Murchison in Ordovician Limestones at Bowan Park,New South Wales     

Vic Semeniuk  John G. Byrnes 《Australian Journal of Earth Sciences》2013,60(3):235-241

Ischadites lindstroemi Hinde 1884 is described from the Ordovician Daylesford Formation (lower part of the Bowan Park Group) of central western New South Wales. The species characterises a distinctive unit in the formation, occurring in bands throughout the unit. From a study of the associated lithofacies and their stratigraphic distribution in the limestones, an interpretation of the environment in which the species lived is presented. The species is considered to have inhabited a shallow‐water, lime‐mud environment, which was off‐shore and marginal to calcarenite shoals.  相似文献   

The mineralogy of the Gosse pile ultramafic intrusion,central Australia. II. Pyroxenes     

A. C. Moore 《Australian Journal of Earth Sciences》2013,60(3):243-258

The orthopyroxenes of Gosse Pile, a layered ultramafic sequence within the Giles Complex of central Australia, show unusual exsolution features such as the development of ‘hour‐glass’ shapes by clinopyroxene lamellae, and also the exsolution of spinel and rutile. Both orthopyroxene and clinopyroxene have high R2O3 contents and their distribution coefficients for Mg and Fe are high (average KD = 0.88). Some, if not all, of these features are considered to indicate that the Gosse Pile rocks crystallized under high pressure. This interpretation also explains the predominance of orthopyroxene over olivine as an early cumulus phase. Estimated conditions during crystallization are 10–14 kilobars and between 1,200‐l,400°C.  相似文献   

Petrochem1.0岩石化学软件及其应用     

丁卫平 《化工矿产地质》2013,(1):52-64

Petrochem1.0岩石化学软件与同类软件相比,有操作简便(左键选数据,右键菜单选功能项),尤其是依据鼠标在不同区域弹出不同的岩性进一步详细定名的对话窗更是其他软件所没有的,提高了工作效率,同时内容也更加丰富。  相似文献   

Geographical information science     

Michael F. Goodchild 《International journal of geographical information science》2013,27(1):31-45

Abstract. Research papers at conferences such as EGIS and the International Symposia on Spatial Data Handling address a set of intellectual and scientific questions which go well beyond the limited technical capabilities of current technology in geographical information systems. This paper reviews the topics which might be included in a science of geographical information. Research on these fundamental issues is a better prospect for long-term survival and acceptance in the academy than the development of technical capabilities. This paper reviews the current state of research in a series of key areas and speculates on why progress has been so uneven. The final section of the paper looks to the future and to new areas of significant potential in this area of research.  相似文献   

甘肃省铅锌矿成矿系列及控矿因素   总被引：7，自引：2，他引：5       下载免费PDF全文

孙矿生  彭德启 《甘肃地质》2004,13(1):1-9

概述了甘肃省铅锌矿资源及分布,根据沉积、火山、岩浆侵入三大主导成矿作用(建造)将全省铅锌矿划分成三大成矿系列,并进一步划分成因类型。以西成盆地与碳酸盐岩和碎屑岩沉积建造有关的层控型铅锌矿为重点,总结了各系列铅锌矿的控矿因素,提出了找矿方向和找矿标志。  相似文献   

全球寒武系年代地层再划分的新建议   总被引：15，自引：6，他引：9  

彭善池  L.E.Babcock 《地层学杂志》2005,29(1):92-93,96

介绍最近提交国际地层委员会寒武系分会的全球寒武系年代地层划分方案 ,划分为 4个统级单位和 10个阶级单位 ,同时提出划分芙蓉统的两个新点位 ,即球接子类三叶虫 Agnostote orientalis和 L otagnostusamericanus的首现。  相似文献