1:2500 000 Map of Precambrian Dyke Swarms and Related Units in North China

正A 1:2500 000 map of major Precambrian mafic dyke swarms and related units in the North China Craton will be presented,and the features and geological implications of~30 swarms will be discussed and summarized:     

Updated Digital Map of Mafic Dyke Swarms and Large Igneous Provinces in Western Australia

正Since 1894,the Geological Survey of Western Australia(GSWA)has released 14 versions of the‘Geological Map of Western Australia’.The latest in this series,published in December 2015,is the first bedrock geology map     

Mechanics of Mafic Dyke Swarms and Breakup of Supercontinent

正Dyke swarms can be divided into three types:parallel dyke swarms,radiating dyke swarms and fan-shape dyke swarm,for which the mechanisms of formation are different(Fig.1).Parallel dyke swarms form in response     

藏南基性岩墙群的地球化学特征

藏南江孜—哲古一带广泛分布有北西向和近东西向产出的基性—中基性岩墙群,它们是新特提斯洋晚期发生大规模扩张的产物。本文对这些基性岩脉进行了较为系统的元素地球化学和Pb-Sr-Nd同位素研究。元素地球化学研究表明,该岩体略为富集LREE,Eu的亏损不明显,表明岩浆结晶分异作用较弱;LILE的富集和HFSE的亏损均不明显,所有样品均以相对富集Ta、Ce和亏损La、Y和Yb为特点。铅同位素206Pb/204Pb比值和207Pb/204Pb比值变化范围较小,分别为18.330～18.717和15.504～15.674;而208Pb/204Pb值和μ值相对变化较大,分别为37.664～39.156和9.296～9.931;初始87Sr/86Sr值变化范围较大,为0.7044～0.7105;岩石的εNd(t)值变化范围为-4.49～ 6.77,绝大多数为正值。微量元素地球化学和Nd-Sr-Pb同位素研究结果表明,藏南地区基性岩墙群可能是由来自亏损地幔源的岩浆与来自富集地幔源(EM)的岩浆混合的产物,其快速侵位造成岩浆分异作用较差,而岩浆的不均匀混合导致LILE富集与HFSE亏损均不明显,并产生较大的初始87Sr/86Sr比...     

华北克拉通晚前寒武纪镁铁质岩墙群K－Ar年龄及地质意义

华北克拉通腹地山西地块内广泛发育大规模的晚前寒武纪镁铁质岩墙群。通过对晋北地区新平堡镁铁质岩墙群９个样品的Ｋ－Ａｒ年龄等时线分析，这些岩墙可能形成于１４３０Ｍａ．从山西各地所采集的６４个镁铁质岩墙群样品的Ｋ－Ａｒ表观年龄统计分析可见，华北克拉通腹地内广泛发育的镁铁质岩墙群主要形成于中元古代１０００～１８００Ｍａ间，活动高峰期在１２００～１６００Ｍａ。     

Large Igneous Provinces,Their Giant Mafic Dyke Swarms,and Links to Metallogeny

正Giant mafic dyke swarms are a key component of the feeder system of Large Igneous Provinces(LIPs),large volume(0.1 Mkm~3;frequently above1 M km~3),mainly mafic(-ultramafic)magmatic events of intraplate affinity.     

The Geochemistry of Late Mesozoic Mafic Dyke Swarms in Fujian Province,Southeast China

正Mafic dyke swarms is a special geologic terrain in continent,which can provide us abundant geodynamic information,mafic dyke swarms were an important symbol of the lithospheric extension,which were mainly derived     

Mafic Dyke Swarms: Their Temporality and Bearing on the Secular Evolution of the Earth

正Pioneering U-Pb isotopic studies by a small group of workers in the mid-late 1980s demonstrated the feasibility of using rare accessory mineral chronometers in mafic(gabbroic)intrusive rocks.These examples showed that mafic layered intrusions and diabase/dolerite dyke swarms alike crystallized high-temperature     

华北晚前寒武纪镁铁质岩墙群的流动构造及侵位机制

华北克拉通中部广泛发育晚前寒武纪镁铁质岩墙群。这些岩墙群未变形和未变质,保存了清晰完好的流动构造,完整地反映了前寒武纪岩浆活动的特征和流动构造,这在世界上是罕见的。通过对晚前寒武纪镁铁质岩墙群的形态和流动构造研究,如:流动线理、矿物组构和磁组构等,提出岩墙群的侵位方向和侵位方式。结合本区岩墙群与燕辽—中条拗拉槽系的关系以及岩墙群的力学性质,探讨本区岩墙群的侵位机制。     

Global Mesozoic and Cenozoic Rift Systems: Constrain on the Tectonic Setting of Mafic Dyke Swarms

正The primary tectonic setting of dyke swarms,especially those formed in the pre-Cambrian era,are under controversy(Peng et al.,2005).However,Mesozoic and Cenozoic rift systems,which are supposed to be the     

Age and Geochemical Characteristics of Major Mafic Dyke Swarms in the Southern Part of the Siberian Craton

正Several generations of mafic dyke swarms of different ages and geochemical characteristics cut Precambrian rocks of the southern part of the Siberian craton(Irkutsk Promontory).Each generation of dykes is related to a     

地幔柱与巨型放射状岩墙群

当前,在对超大陆和超大陆事件研究过程中,对地幔柱引发的超大陆裂解作用普遍引起了重视.为进一步在国内开展同一领域的研究工作,作者在介绍地幔柱一般特征的基础上,着重阐述了作为地幔柱活动产物之一的巨型放射状岩墙群的特点及国外元古宙基性岩墙群的几个实例,同时对我国古元古代初期、中元古代初期和新元古代等三个时期的基性岩墙群的分布及年代学做了简略小结,指出我国在前寒武纪基性岩墙群研究工作中应在岩相学和地球化学研究的基础上,进一步注意对其产状、形态、规模和精确定年的研究.     

Radiating 1.0 Ga Mafic Dyke Swarms of Eastern Brazil and Western Africa: Evidence of Post-Assembly Extension in the Rodinia Supercontinent?

Several mafic dyke swarms of similar composition and age (tholeiite- ca.1.0 Ga) occur on both sides of the Atlantic Ocean in eastern South America and western Africa. When assembled to their pre-drift position in the Mesozoic, the Brazilian coastal dyke province of Bahia, and the African dykes in Cameroun (Ebolowa suite) and Congo (Comba and Sembe-Ouesso provinces) define a giant radiating pattern (1200 km × 800 km) similar to other dyke swarms elsewhere associated with large-scale continental rifting. Magma flow indicators of the Brazilian dykes and branching propagation styles of their African counterparts indicate that the dyke conduits were fed with magmas diverging from a source beneath the long axis of the Meso-Neoproterozoic West-Congolian Basin in Africa. There, MORB-like metabasalts have been described in the La Bikossi Group of the Mayombian Supergroup. Whether the rifting event and intrusion of dyke swarms were triggered or not by a mantle plume beneath part of the Rodinia subcontinental lithosphere remain to be confirmed.     

Neoarchaean-Palaeoproterozoic Mafic Dyke Swarms from the Singhbhum Granite Complex,Singhbhum Craton,Eastern India: Implications for Identification of Large Igneous Provinces and Their Possible Continuation on Other Formerly Adjacent Crustal Blocks

正The Singhbhum craton of the eastern India consists of the Singhbhum Granite Complex(SGC)and the Chotanagpur Gneissic Complex(CGC)separated by the Singhbhum Mobile Belt(SMB).The CGC is intruded by Mesoproterozoic as well as Cretaceous mafic dykes;in     

Proterozoic Dyke Swarms of the Siberian Craton and Their Geodynamic Implications

正We present a summary of late Paleoproterozoic to Neoproterozoic mafic magmatism in the Siberian craton which allows us distinguish following main pulses of mafic dyke emplacement:1)1860–1850 Ma mafic dykes are localized within the     

The 2405 Ma and 2310 Ma Mafic Dyke Swarms in the Karelian Craton: Age,Chemical and Sr-Nd Isotope Composition,and Tectonic Setting

正Until recently the time period 2400-2200 Ma in the Erath history was characterized by low amount of age data for igneous events,and was even considered as‘magmatic age gap’(Condie et al,2009;Eriksson and Condie,2014).     

Mapping the Dyke Swarms of the Eastern Desert,Egypt

正The Eastern Desert of Egypt hosts numerous undeformed to slightly deformed mafic dyke swarms which have previously been poorly characterized.Systematic use of full resolution Google Earth?images yields an initial     

Geochemistry and Emplacement of Post-collisional Shoshonitic Dyke Swarms,NW of Iran

正About 300 mafic dykes are intruded Eocene volcanic and pyroclastic rocks,north east of Meshkinshahr city in the NW of Iran.Most of dyke swarms display NNE-SSE trend.Their composition varies from basalt to tephrite and     

Mapping the Dyke Swarms of the Eglab-Yetti Region,Southwestern Algeria

正The Eglab-Yetti region of southwestern Algeria is a main part of the Reguibat shield of the West African craton(WAC)which consists of Archean to Paleoprotzrozoic basement.The region hosts numerous