Final report of IGCP Project 410 （1997-2002）——The Great Ordovician Biodiversification Event Department of Earth and Planetary Sciences, Macquarie University, North Ryde, NSW 2109, Australia. E-mail： bwebby@laurel.ocs.mq.edu.au     

BarryDWebby MaryL.Droser FlorentinParis 《《幕》》2004,27(3):203-208

In 1997, IGCP Project No. 410 was established to appraise known records of Ordovician biotas, in order to evaluate one of the greatest-ever diversifications of life on Earth, between 489 and 443 million years ago. Data collection and analysis of biodiversity were coordinated through seven regional teams, and a global“clade” team.  相似文献   

梦想晚白垩纪公园     

刘长春 《浙江国土资源》2004,(5):58-59

晚白垩纪是地质学的一个新名词,距今大约五千万至七千万年. 轻轻的,我像往常一样走进这片熟悉的土地.如果没有人告诉我,脚下这块偌大的冲击盆地在白垩纪早期竟是一个碧波荡漾的湖泊,很难想象它有多么的古老.  相似文献   

台湾地层检讨(续)     

张丽旭 《地质论评》1948,13(Z3):291-310

所谓‘大寮层’者,以页岩与砂岩之交互层为主,厚约350公尺,在其上部,砂岩发育较佳,而在山下部则反是。砂岩往住带石灰质并含有化石,尤其在上部有富含Ditrupa sp之灰质的砂岩发现,所谓Ditrupa化石带是也。此外尚有下列之化石发现:  相似文献   

重庆地面最高气温与最大风速年极值的渐近分布   总被引：3，自引：0，他引：3  

孟庆珍  王增武  冯新  梁秋枫 《成都信息工程学院学报》2004,19(3):436-441

利用重庆1951-1990年间地面最高气温和1956-1990年间地面最大风速年极值的记录,采用韦伯分布和耿贝尔分布分别对其渐近分布进行拟合.通过统计推断,找出重庆地面最高气温和地面最大风速年极值遵循的最佳渐近分布--韦伯分布.  相似文献   

The Geologic Time Scale and the Italian stratigraphic record     

DomenicoRio IsabellaPremoliSilva LucaCapraro 《《幕》》2003,26(3):259-263

The construction of the Geologic Time Scale (GTS) is a titanic scientific challenge that has been under way for two centuries and will require much dedicated effort in the future. Italy preserves a paramount stratigraphic record of Mesozoic and Cenozoic marine sediments that have been significant in the development of the modern GTS. The Italian stratigraphic record has been histori-cally important in introducing and defining the standard Chronostratigraphic Units (CUs) of the Neogene and Quaternary. Pelagic successions from Northern Apen-nines and Southern Alps have been used in the seventies for integrating the late Cretaceous-Paleogene Geomag-netic Polarity Time Scale (GPTS) with planktonic microfossil biostratieraohv and standard CUs. This was a major contribution to the construction of a new gener-ation of GTS based on integrated magnetobiochronol-ogy. The middle Miocene to early Pleistocene marinerecord from Sicily and southern Italy has been funda-mental for establishing the recently developed Astro-nomical Time Scale (ATS). In prospect, there are many potentials still to be exploited in the Italian marine stratigraphic record for implementing the GTS by defin-ing GSSPs of various CUs, improving magneto-biochronology and extending downwards the ATS.  相似文献   

瓮安生物群与宽川铺生物群中球形类化石研究   总被引：2，自引：0，他引：2  

刘云焕  李勇  邵铁全  于波  付淑青  韩会平  李园园  李荣西 《地球科学与环境学报》2005,27(1):5-13

通过对获自瓮安生物群与宽川铺生物群中大量球形类化石的系统研究，建立了便于交流和深入讨论的球形类化石形态分类方案，对各种类型的球形类化石进行了属性探讨，并按形态属描述球形类化石4个新类型(相当于形态属)，8个新种类(相当于形态种)。研究表明球形类化石是一个多源的非正式生物类群，包括动物性和植物性球形类化石。具有丰富的研究内涵，对揭示早期生物的起源、演化、多样性及胚胎发育具有深远意义。  相似文献   

联邦国土上化石采集的政策讨论     

Pojeta  J 方勤 《地质科学译丛》1994,11(3):87-88

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浅析宁波盆地膏盐地层的时代──兼对“宁波盆地北部的长河群”之时代质疑     

鞠天吟 《浙江国土资源》1995,(1)

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   

对我国古生物化石自动化鉴定和分类研究的商讨     

雒昆利 《长春地质学院学报》1992,22(3):315-316,232

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Mantle processes during ocean formation：Petrologic records in peridotites from the Alpine－Apennine ophiolites     

GiovanniB.Piccardo 《《幕》》2003,26(3):193-199

Mantle peridotites were early exposed at the sea-floor of the Jurassic Tethys derived from the subcontinental mantle of the Europe-Adria system. During continental rifting and oceanic spreading, these lithospheric peri-dotites were percolated via diffuse reactive porous flowby melt fractions produced by near-fractional melting of the upwelling asthenosphere. Ascending melts inter-acted with the lower lithosphere, dissolving pyroxenes and precipitating olivine, and crystallized at shallower levels in the mantle column causing melt impregnation.Subsequent focused porous flow formed replacive dunitechannels, cutting the impregnated oeridotites, which were conduits for upward migration of MORB-type liq-uids. Melt migration produced depletionlrefertilization and significant heating of the percolatedlimpregnated mantle, i.e the thermochemical erosion of the litho-sphere. Impregnated and thermally modified lithos-pheric mantle was cooled by conductive heat loss dur-ing progressive lithosphere thinning and was intrudeaby MORB magmas, which formed Mg-rich and Fe-richgabbroic dykes and bodies. Alpine-Apennine ophiolitic peridotites record the deep-seated migration of melts which changed their compositions and dynamics during the rift evolution. The thermochemical erosion of the lithospheric mantle by the ascending asthenospheric melts, which induces significant compositional and rhe-ological changes in the lower lithosphere, is a major process in the evolution of the continent-ocean transi-tion towards a slow spreading oceanic system.  相似文献