mafic

• These deposits , which can be obviously divided into basic and acid volcanic types , are present in the carboniferous bi - model volcanic series and occur along two horizons , i . e . , the lower carboniferous mafic volcanic rock and the upper carboniferous felsic volcanic rock
  这些矿床产在石炭系双峰式火山岩系之内，沿著下石炭统基性火山岩和上石炭统酸性火山岩两个层位产出，分别以玄武岩和流纹岩为容矿主岩，可以明显地分成基性火山岩型和酸性火山岩型两种类型。
• These mafic dykes may provide some important insights about the mantle processes at ca . 1800 - 1700 ma and their geodynamic implications . unfortunately , more attention has been paid to palaeomagnetic , petrologic , lithochemical and k - ar geochronological studies of these mafic dykes
  该论文现在对作为华北陆块早元古代基性岩墙群重要组成部分的南太行山地区基性岩脉开展了较为系统的年代学、元素和同位素研究，以期为理解华北陆块1800ma构造背景提供新的资料。
• The mafic dikes also formed by the partial melting of enriched mantle , include gabbro , diabase ( distributing mainly in luxi ) and lamprophyres ( camptovogesite , odinite and hornblende lamprophyres ) ( mainly in ludong ) . for all the rocks , crustal contamination was absent when magma emplaced . 2
  基性脉岩主要包括辉长岩、辉绿岩(主要分布在鲁西地区)和煌斑岩(以斜闪煌斑岩为主，同时含部分拉辉煌斑岩和角闪煌斑岩) (主要分布在鲁东地区) ，都为富集岩石圈地幔部分熔融的产物。
• On the basis of analysis and comparison between two drills , one in the center of bohai sea , another near the west shore of bohai sea , ultra - long electromagnetic wave remote sensing can be applied to forecast the interfaces between the different rocks , and help to choose the location of drill and drilling plan . the ultra - long electromagnetic remote sensing also can be applied to general investigation in the prospecting area and organizing the structural map on the basis of the profiles and plane . based on the analysis of the ultra - long electromagnetic wave curves from tanggu to dalian , the geological body to effect the high gravity and magnetic anomalies could be a mafic intrusion . the magma activity provided the heat source to organic maturation in the center of bohai sea , so the center of bohai sea could be the prospection of deep gas in bohai sea
  根据渤海西岸和渤海中部两口探井的探测和对比实验分析，利用超长电磁波遥测技术可以根据已知探井的探测对比分析预测新探井的岩性界面，协助井位的选址和设计。另外，利用超长电磁波的探测技术可以从剖面和平面上对远景区进行普查性探测，编制远景区的构造图。根据塘沽-大连探测的超长电磁波频谱曲线剖面对比分析，证实引起渤海中部重磁异常高的地质体可能是基性超基性岩体。
• The southern hainan mafic dykes are strongly enriched in lile with high nb / ta ratios , indicating a magma source reconstructed by silicic - melt through partial melting of ancient subducted slides . however , the northern hainan mafic dykes with chondritic nb / ta ratio should be derived from the fiuid - metasomatized mantle related to ancient subduction zone
  琼南基性岩脉强烈富k _ 2o等lile和具有较高nb ta比值，其地幔源区应受到了古俯冲板片部分熔融形成的硅质熔体的改造；而琼中基性岩脉的nb ta比值接近于球粒陨石和morb值，应为古俯冲带含水流体交代的地幔源区的产物。
• Integrating the ages of the mafic dikes and alkalic - ultramafic dikes in this paper , and the known data of mafic dikes and volcanic rocks , at least , there existed four episodes mesozoic crustal extension in shandong province , namely , 80ma , 100ma , 120 ma and140ma , which is similar to that of sc ( south china ) , indicating that maybe the effect of the subductio
  但鲁东地区在地壳拉张方面可能存在着与鲁西地区不同的制约因素：即鲁东地区存在拆沉作用和可能存在地慢柱的影响’ 、而鲁西地区可能受到了郊庐断裂的左行走滑剪切和拉张活动的影响。
• On the basis of detailed and systematic studies on the petrography , major and trace elements and sr - nd isotopic data of mesozoic volcanic rocks , especially the mafic volcanic rocks in yanshan area , we successfully studied the deep processes related to magma generation and their relationship with shallow - level tectonic evolution . the major conclusions are summarized as below . 1
  论文通过对燕山地区中生代火山岩，特别是中基性火山岩，进行详细而系统的岩石学、主微量元素地球化学特征和sr - nd同位素组成特征的研究，主要取得了以下研究成果： 1燕山地区中生代( j - k )火山岩为一套钙碱性-高钾钙碱性-橄榄安粗岩系列岩石。
• The mafic rocks have high ( 87sr / 86sr ) j ( 0 . 7046 - 0 . 7077 ) and 207pb / 204pb ( 15 . 47 - 15 . 67 ) , but relatively low in ( 143nd / 144nd ) i ( 0 . 5125 - 0 . 5127 ) and 206pb / 204pb ( 18 . 26 - 18 . 52 ) . the negative correlation between 143nd / 144nd and 206pb / 204pb and the positive relationship between 87sr / 86sr - 206pb / 204pb suggest a mixing of a depleted mantle source and an em2 component in the study area . calculation reveals that the maopin - shaianjiao mafic rocks are formed by 5 - 15 % degree of partial melting of an lree - riched spinel iherzolite
  模拟计算表明，该基性岩墙群是尖晶石二辉橄榄岩地幔5 - 15部分熔融的产物；微量元素配分模式及理论模拟表明茅坪?晒鞍角基性岩体的地幔源区在熔融前曾受到1俯冲沉积物熔体的源区混染和5流体交代作用。
• A ree partition simulation suggests that the tianzhushan intermediate rocks can be generated by partial melting , in coupling with fractional crystallization , of dioritic gneiss which is similar in chemical compositions to the mafic rocks in the lower crust in north dabie ; partial melting of intermediate grey gneiss which is similar in chemical compositions to the middle crust in north dabie can generate the tianzhushan felsic rocks
  Ree配分的定量模拟计算结果表明，与基性下地壳相似的北大别基性闪长质片麻岩部分熔融并经过结晶分异能够形成与天柱山中性岩类似的稀土元素组成，而与中性地壳相似的北大别中性灰色片麻岩部分熔融能够形成与天柱山花岗岩类似的稀土元素组成。
• The mantle source for the mesozoic mafic volcanic rocks in yanshan area exhibit transition character in space and time : the mantle source components vary from subduction - related metasomatic components and emi components through dominant emi components and slight subduction - related metasomatic components to emi components ; spatially , mantle source of the volcanic rocks show a regular variation trend from an enriched lithospheric mantle with emi - like signatures in the western shandong province through emi and / or subduction - related metasomatic components in yanshan area to subduction - related metasomatic lithospheric mantle in the hinggan - mongolian orogen
  燕山地区中酸性火山岩则来源于地壳，与玄武质岩浆底侵作用关系密切。 3燕山地区火山岩源区组分在时空上具有一定的演化规律：在时间上，从早期俯冲交代地幔及emi的参与，经中期以emi占主导及极少量俯冲交代组分的阶段，演变到晚期以emi为主，可能有少量软流圈贡献的组分，再到晚白垩世以软流圈为主。