冀西北姚家庄超镁铁岩-正长岩杂岩体中辉石的环带特征及意义
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摘要
冀西北姚家庄存在一套晚三叠世的超镁铁岩-正长岩杂岩体,岩体内发育具有环带特征的单斜辉石。辉石的环带有两种:简单环带和复杂环带。简单环带一般为正环带,辉石核部的MgO和Cr2O3含量高,Si O2、Fe O和Na2O含量低;边部的主要氧化物含量与核部刚好相反。简单正环带可以分为两类,其中核边接触带平滑、由核到边化学成分具有渐变特征的正环带辉石可能是岩浆在分离结晶或地壳混染过程中形成。而核边接触带有熔蚀结构、由核到边化学成分突变的正环带辉石可能是早期结晶的辉石颗粒受到晚期低镁岩浆的溶蚀改造而成的。复杂环带具有核-幔-边结构,其中,核部低镁高铁、幔部高镁低铁、边部与核部相似,但其Mg#更低,这些特征暗示了岩浆混合作用的存在,形成辉石核部的母岩浆可能来自富集的岩石圈地幔,幔部高Mg#的特征指示了软流圈地幔物质的贡献,其边部低Mg#的特征则指示了地壳物质的加入。具有韵律环带的复杂辉石是在岩浆多期侵入的过程中形成的。辉石环带的组成特征表明,姚家庄杂岩体是由岩浆多期侵位形成的,后期侵入的岩浆与前期就位的岩浆不断反应,形成了具有多种不同环带特征的辉石,并最终形成了空间上由外到内依次为辉石岩、辉石正长岩和正长岩的环状杂岩体。结合前人的研究成果,推测形成姚家庄岩体的岩浆主要来源于富集的岩石圈地幔,并由少量地壳组分和软流圈物质的贡献。
Ultramafic-syenitic complex in the Yaojiazhuang,northwestern Hebei Province,contains abundant clinopyroxene phenocrysts with compositional zonations,which can be divided into two kind of patterns: simple zoning and complex zoning. All the simple zonings are in normal pattern. The cores of the grains show high contents of the Al2 O3,Fe O,Na2 O and low contents of MgO and Cr2 O3,while the rims of zonation are opposite to the cores. Two different kind of simple zonations are recognized. The chemical composition of some clinopyroxene phenocrysts changed gradually from the core to the rim of grains,which could be crystallized from the host magma of varying compositions caused by the assimilation of crustal materials or crystal fractionation. Whereas,other phenocrysts show compositional variation in an abrupt change from core to rim of grains with corrosion texture,possibly caused by the modification of early-crystallized clinopyroxenes by later magmas. The clinopyroxene phenocrysts with complex zoning have core-mantlerim texture. The core of zonation is relatively low in Mg#,but high in Fe O content,while the mantle of zonation is clearly high in Mg#and low in Fe O content. The rim of zonation is lower in Mg#values than the core. These observations indicate the mixing of different magmas. The core of zonation could crystallize from the host magma derived from metasomatized lithospheric mantle. The high-Mg#mantle of zonation indicates the contribution of the asthenospheric melt,and the low-Mg#rim of clinopyroxene phenocrysts could be resulted from the addition of crustal materials. In conclusion,the zonations of clinopyroxene phenocrysts suggest that the Yaojiazhuang complex could be formed by multiple stage magmatic intrusion. The later magmas continuously intruded and reacted with the former host magma. As a result,abundant clinopyroxene phenocrysts with compositional zonations formed,and the pyroxenite,pyroxenitesyenite,and syenite occurred in sequence. Combined with the previous studies,the parent magma of Yaojiazhuang complex could originate from the enriched lithospheric mantle,with minor contributions of asthenosphere and crustal materials.
Ultramafic-syenitic complex in the Yaojiazhuang,northwestern Hebei Province,contains abundant clinopyroxene phenocrysts with compositional zonations,which can be divided into two kind of patterns: simple zoning and complex zoning. All the simple zonings are in normal pattern. The cores of the grains show high contents of the Al2 O3,Fe O,Na2 O and low contents of MgO and Cr2 O3,while the rims of zonation are opposite to the cores. Two different kind of simple zonations are recognized. The chemical composition of some clinopyroxene phenocrysts changed gradually from the core to the rim of grains,which could be crystallized from the host magma of varying compositions caused by the assimilation of crustal materials or crystal fractionation. Whereas,other phenocrysts show compositional variation in an abrupt change from core to rim of grains with corrosion texture,possibly caused by the modification of early-crystallized clinopyroxenes by later magmas. The clinopyroxene phenocrysts with complex zoning have core-mantlerim texture. The core of zonation is relatively low in Mg#,but high in Fe O content,while the mantle of zonation is clearly high in Mg#and low in Fe O content. The rim of zonation is lower in Mg#values than the core. These observations indicate the mixing of different magmas. The core of zonation could crystallize from the host magma derived from metasomatized lithospheric mantle. The high-Mg#mantle of zonation indicates the contribution of the asthenospheric melt,and the low-Mg#rim of clinopyroxene phenocrysts could be resulted from the addition of crustal materials. In conclusion,the zonations of clinopyroxene phenocrysts suggest that the Yaojiazhuang complex could be formed by multiple stage magmatic intrusion. The later magmas continuously intruded and reacted with the former host magma. As a result,abundant clinopyroxene phenocrysts with compositional zonations formed,and the pyroxenite,pyroxenitesyenite,and syenite occurred in sequence. Combined with the previous studies,the parent magma of Yaojiazhuang complex could originate from the enriched lithospheric mantle,with minor contributions of asthenosphere and crustal materials.
引文
Chen B,Niu XL,Wang ZQ,Gao L and Wang C.2013.Geochronology,petrology,and geochemistry of the Yaojiazhuang ultramafic-syenitic complex from the North China Craton.Science China(Earth Sciences),56(8):1294-1307
Chi JS and Lu FX.1996.Kimberlites on the North China Craton and Features of Paleozoic Lithospheric Mantle.Beijing:Science Press,1-292(in Chinese)
Dobosi G.1989.Clinopyroxene zoning patterns in the young alkali basalts of Hungary and their petrogenetic significance.Contributions to Mineralogy and Petrology,101(1):112-121
Han BF,Kagami H and Li HM.2004.Age and Nd-Sr isotopic geochemistry of the Guangtoushan alkaline granite,Hebei Province,China:Implications for Early Mesozoic crust-mantle interaction in North China Block.Acta Petrologica Sinica,20(6):1375-1388(in Chinese with English abstract)
Huang XL,Niu YL,Xu YG,Chen LL and Yang QJ.2010.Mineralogical and geochemical constraints on the petrogenesis of post-collisional potassic and ultrapotassic rocks from western Yunnan,SW China.Journal of Petrology,51(8):1617-1654
Loucks RR.1990.Discrimination of ophiolitic from nonophiolitic ultramafic-mafic allochthons in orogenic belts by the Al/Ti ratio in clinopyroxene.Geology,18(4):346-349
Nisbet EG and Pearce JA.1977.Clinopyroxene composition in mafic lavas from different tectonic settings.Contributions to Mineralogy and Petrology,63(2):149-160
Niu XL,Yang JS,Feng GY and Liu F.2015.Mineral chemistry of biotites from the Fanshan ultramafic-syenitic complex and its petrogenetic significance.Acta Geologica Sinica,89(6):1108-1119(in Chinese with English abstract)
Ren KX,Yan GH,Mou BL,Cai JH,Li FT,Tan LK,Shao HX,Li YKand Chu ZY.2004.Geochemical characteristics and geological implications of the Hekanzi alkaline complex in Lingyuan County,western Liaoning Province.Acta Petrologica et Mineralogica,23(3):193-202(in Chinese with English abstract)
Shao JA,Lu FX,Zhang LQ and Yang JH.2005.Discovery of xenocrysts in basalts of Yixian formation in West Liaoning Province and its significance.Acta Petrologica Sinica,21(6):1547-1558(in Chinese with English abstract)
Sun SS and Mc Donough WF.1989.Chemical and isotopic systematics of oceanic basalts:Implications for mantle composition and processes.In:Saunders AD and Norry MJ(eds.).Magmatism in the Ocean Basins.Geological Society,London,Special Publications,42(1):313-345
Tang GJ,Wang Q,Wyman DA,Li ZX,Xu YG and Zhao ZH.2012.Metasomatized lithosphere-asthenosphere interaction during slab rollback:Evidence from Late Carboniferous gabbros in the Luotuogou area,Central Tianshan.Lithos,155:67-80
Tang YJ,Zhang HF,Ying JF and Su BX.2013.Widespread refertilization of cratonic and circum-cratonic lithospheric mantle.Earth-Science Reviews,118:45-68
Tang YJ,Zhang HF and Ying JF.2014.Genetic significance of Triassic alkali-rich intrusive rocks in the Yinshan and neighboring areas.Acta Petrologica Sinica,30(7):2031-2040(in Chinese with English abstract)
Xiao WJ,Windley BF,Hao J and Zhai MG.2003.Accretion leading to collision and the Permian Solonker suture,Inner Mongolia,China:Termination of the Central Asian Orogenic belt.Tectonics,22(6):1069
Yan GH,Mou BL,Xu BL,He GQ,Tan LK,Zhao H,He ZF,Zhang RH and Qiao GS.1999.Triassic alkaline intrusives in the YanliaoYinshan area:Their chronology,Sr,Nd and Pb isotopic characteristics and their implication.Science in China(Series D),42(6):582-587
Yang JH,Sun JF,Zhang M,Wu FY and Wilde SA.2012.Petrogenesis of silica-saturated and silica-undersaturated syenites in the northern North China Craton related to post-collisional and intraplate extension.Chemical Geology,328:149-167
Ying JF,Zhang HF and Tang YJ.2011.Crust-mantle interaction in the central North China Craton during the Mesozoic:Evidence from zircon U-Pb chronology,Hf isotope and geochemistry of syeniticmonzonitic intrusions from Shanxi Province.Lithos,125(1-2):449-462
Zhang HF,Ying JF,Shimoda G,Kita NT,Morishita Y,Shao JA and Tang YJ.2007.Importance of melt circulation and crust-mantle interaction in the lithospheric evolution beneath the North China Craton:Evidence from Mesozoic basalt-borne clinopyroxene xenocrysts and pyroxenite xenoliths.Lithos,96(1-2):67-89
Zhang HF,Goldstein S,Zhou XH,Sun M,Zheng JP and Cai Y.2008.Evolution of subcontinental lithospheric mantle beneath eastern China:Re-Os isotopic evidence from mantle xenoliths in Paleozoic kimberlites and Mesozoic basalts.Contributions to Mineralogy and Petrology,155:271-293
Zhang SH,Zhao Y,Liu JM,Hu JM,Song B,Liu J and Wu H.2010.Geochronology,geochemistry and tectonic setting of the Late Paleozoic-Early Mesozoic magmatism in the northern margin of the North China Block:A preliminary review.Acta Petrologica et Mineralogica,29(6):824-842(in Chinese with English abstract)
Zhang ZC and Wang YQ.1997.Indosinian alkaline magmatism in North Hebei Province and its geodynamic significance.Bulletin of Mineralogy,Petrology and Geochemistry,16(4):214-217(in Chinese with English abstract)
Zhang ZC.1999.Rock associations and petrogenesis of Indosinian alkaline complex of the North Hebei Province,North China.Scientia Geologica Sinica,8(1):65-76
Zhang Z,Zhang HF,Shao JA,Ying JF,Yang YH and Santosh M.2012.Guangtoushan granites and their enclaves:Implications for Triassic mantle upwelling in the northern margin of the North China Craton.Lithos,149:174-187
Zheng JP and Lu FX.1999.Mantle xenoliths from kimberlites,Shandong and Liaoning:Paleozoic mantle character and its heterogeneity.Acta Petrologica Sinica,15(1):65-74(in Chinese with English abstract)
Zhu YS,Yang JH,Sun JF,Zhang JH and Wu FY.2016.Petrogenesis of coeval silica-saturated and silica-undersaturated alkaline rocks:Mineralogical and geochemical evidence from the Saima alkaline complex,NE China.Journal of Asian Earth Sciences,117:184-207
陈斌,牛晓露,王志强,高林,王超.2013.华北克拉通北缘姚家庄过钾质超镁铁岩-正长岩杂岩体的锆石U-Pb年代学、岩石学和地球化学特征.中国科学(地球科学),43(7):1073-1087
池际尚,路凤香.1996.华北地台金伯利岩及古生代岩石圈地幔特征.北京:科学出版社,1-292
韩宝福,加加美宽雄,李惠民.2004.河北平泉光头山碱性花岗岩的时代、Nd-Sr同位素特征及其对华北早中生代壳幔相互作用的意义.岩石学报,20(6):1375-1388
牛晓露,杨经绥,冯光英,刘飞.2015.河北矾山超镁铁岩-正长岩杂岩体中黑云母的特征及其成岩指示意义.地质学报,89(6):1108-1119
任康绪,阎国翰,牟保磊,蔡剑辉,李凤棠,谭林坤,邵宏翔,李元崑,储著银.2004.辽西凌源河坎子碱性杂岩体地球化学特征及地质意义.岩石矿物学杂志,23(3):193-202
邵济安,路凤香,张履桥,杨进辉.2005.辽西义县组玄武岩捕虏晶的发现及其意义.岩石学报,21(6):1547-1558
汤艳杰,张宏福,英基丰.2014.阴山及邻区三叠纪富碱侵入岩的成因意义.岩石学报,30(7):2031-2040
阎国翰,牟保磊,许保良,何国琦,谭林坤,赵晖,何中甫,张任祜,乔广生.2000.燕辽-阴山三叠纪碱性侵入岩年代学和Sr,Nd,Pb同位素特征及意义.中国科学(D辑),30(4):383-387
张拴宏,赵越,刘建民,胡健民,宋彪,刘健,吴海.2010.华北地块北缘晚古生代-早中生代岩浆活动期次、特征及构造背景.岩石矿物学杂志,29(6):824-842
张招崇,王永强.1997.冀北印支期碱性岩浆活动及其地球动力学意义.矿物岩石地球化学通报,16(4):214-217
郑建平,路凤香.1999.胶辽半岛金伯利岩中地幔捕虏体岩石学特征:古生代岩石圈地幔及其不均一性.岩石学报,15(1):65-74
Chi JS and Lu FX.1996.Kimberlites on the North China Craton and Features of Paleozoic Lithospheric Mantle.Beijing:Science Press,1-292(in Chinese)
Dobosi G.1989.Clinopyroxene zoning patterns in the young alkali basalts of Hungary and their petrogenetic significance.Contributions to Mineralogy and Petrology,101(1):112-121
Han BF,Kagami H and Li HM.2004.Age and Nd-Sr isotopic geochemistry of the Guangtoushan alkaline granite,Hebei Province,China:Implications for Early Mesozoic crust-mantle interaction in North China Block.Acta Petrologica Sinica,20(6):1375-1388(in Chinese with English abstract)
Huang XL,Niu YL,Xu YG,Chen LL and Yang QJ.2010.Mineralogical and geochemical constraints on the petrogenesis of post-collisional potassic and ultrapotassic rocks from western Yunnan,SW China.Journal of Petrology,51(8):1617-1654
Loucks RR.1990.Discrimination of ophiolitic from nonophiolitic ultramafic-mafic allochthons in orogenic belts by the Al/Ti ratio in clinopyroxene.Geology,18(4):346-349
Nisbet EG and Pearce JA.1977.Clinopyroxene composition in mafic lavas from different tectonic settings.Contributions to Mineralogy and Petrology,63(2):149-160
Niu XL,Yang JS,Feng GY and Liu F.2015.Mineral chemistry of biotites from the Fanshan ultramafic-syenitic complex and its petrogenetic significance.Acta Geologica Sinica,89(6):1108-1119(in Chinese with English abstract)
Ren KX,Yan GH,Mou BL,Cai JH,Li FT,Tan LK,Shao HX,Li YKand Chu ZY.2004.Geochemical characteristics and geological implications of the Hekanzi alkaline complex in Lingyuan County,western Liaoning Province.Acta Petrologica et Mineralogica,23(3):193-202(in Chinese with English abstract)
Shao JA,Lu FX,Zhang LQ and Yang JH.2005.Discovery of xenocrysts in basalts of Yixian formation in West Liaoning Province and its significance.Acta Petrologica Sinica,21(6):1547-1558(in Chinese with English abstract)
Sun SS and Mc Donough WF.1989.Chemical and isotopic systematics of oceanic basalts:Implications for mantle composition and processes.In:Saunders AD and Norry MJ(eds.).Magmatism in the Ocean Basins.Geological Society,London,Special Publications,42(1):313-345
Tang GJ,Wang Q,Wyman DA,Li ZX,Xu YG and Zhao ZH.2012.Metasomatized lithosphere-asthenosphere interaction during slab rollback:Evidence from Late Carboniferous gabbros in the Luotuogou area,Central Tianshan.Lithos,155:67-80
Tang YJ,Zhang HF,Ying JF and Su BX.2013.Widespread refertilization of cratonic and circum-cratonic lithospheric mantle.Earth-Science Reviews,118:45-68
Tang YJ,Zhang HF and Ying JF.2014.Genetic significance of Triassic alkali-rich intrusive rocks in the Yinshan and neighboring areas.Acta Petrologica Sinica,30(7):2031-2040(in Chinese with English abstract)
Xiao WJ,Windley BF,Hao J and Zhai MG.2003.Accretion leading to collision and the Permian Solonker suture,Inner Mongolia,China:Termination of the Central Asian Orogenic belt.Tectonics,22(6):1069
Yan GH,Mou BL,Xu BL,He GQ,Tan LK,Zhao H,He ZF,Zhang RH and Qiao GS.1999.Triassic alkaline intrusives in the YanliaoYinshan area:Their chronology,Sr,Nd and Pb isotopic characteristics and their implication.Science in China(Series D),42(6):582-587
Yang JH,Sun JF,Zhang M,Wu FY and Wilde SA.2012.Petrogenesis of silica-saturated and silica-undersaturated syenites in the northern North China Craton related to post-collisional and intraplate extension.Chemical Geology,328:149-167
Ying JF,Zhang HF and Tang YJ.2011.Crust-mantle interaction in the central North China Craton during the Mesozoic:Evidence from zircon U-Pb chronology,Hf isotope and geochemistry of syeniticmonzonitic intrusions from Shanxi Province.Lithos,125(1-2):449-462
Zhang HF,Ying JF,Shimoda G,Kita NT,Morishita Y,Shao JA and Tang YJ.2007.Importance of melt circulation and crust-mantle interaction in the lithospheric evolution beneath the North China Craton:Evidence from Mesozoic basalt-borne clinopyroxene xenocrysts and pyroxenite xenoliths.Lithos,96(1-2):67-89
Zhang HF,Goldstein S,Zhou XH,Sun M,Zheng JP and Cai Y.2008.Evolution of subcontinental lithospheric mantle beneath eastern China:Re-Os isotopic evidence from mantle xenoliths in Paleozoic kimberlites and Mesozoic basalts.Contributions to Mineralogy and Petrology,155:271-293
Zhang SH,Zhao Y,Liu JM,Hu JM,Song B,Liu J and Wu H.2010.Geochronology,geochemistry and tectonic setting of the Late Paleozoic-Early Mesozoic magmatism in the northern margin of the North China Block:A preliminary review.Acta Petrologica et Mineralogica,29(6):824-842(in Chinese with English abstract)
Zhang ZC and Wang YQ.1997.Indosinian alkaline magmatism in North Hebei Province and its geodynamic significance.Bulletin of Mineralogy,Petrology and Geochemistry,16(4):214-217(in Chinese with English abstract)
Zhang ZC.1999.Rock associations and petrogenesis of Indosinian alkaline complex of the North Hebei Province,North China.Scientia Geologica Sinica,8(1):65-76
Zhang Z,Zhang HF,Shao JA,Ying JF,Yang YH and Santosh M.2012.Guangtoushan granites and their enclaves:Implications for Triassic mantle upwelling in the northern margin of the North China Craton.Lithos,149:174-187
Zheng JP and Lu FX.1999.Mantle xenoliths from kimberlites,Shandong and Liaoning:Paleozoic mantle character and its heterogeneity.Acta Petrologica Sinica,15(1):65-74(in Chinese with English abstract)
Zhu YS,Yang JH,Sun JF,Zhang JH and Wu FY.2016.Petrogenesis of coeval silica-saturated and silica-undersaturated alkaline rocks:Mineralogical and geochemical evidence from the Saima alkaline complex,NE China.Journal of Asian Earth Sciences,117:184-207
陈斌,牛晓露,王志强,高林,王超.2013.华北克拉通北缘姚家庄过钾质超镁铁岩-正长岩杂岩体的锆石U-Pb年代学、岩石学和地球化学特征.中国科学(地球科学),43(7):1073-1087
池际尚,路凤香.1996.华北地台金伯利岩及古生代岩石圈地幔特征.北京:科学出版社,1-292
韩宝福,加加美宽雄,李惠民.2004.河北平泉光头山碱性花岗岩的时代、Nd-Sr同位素特征及其对华北早中生代壳幔相互作用的意义.岩石学报,20(6):1375-1388
牛晓露,杨经绥,冯光英,刘飞.2015.河北矾山超镁铁岩-正长岩杂岩体中黑云母的特征及其成岩指示意义.地质学报,89(6):1108-1119
任康绪,阎国翰,牟保磊,蔡剑辉,李凤棠,谭林坤,邵宏翔,李元崑,储著银.2004.辽西凌源河坎子碱性杂岩体地球化学特征及地质意义.岩石矿物学杂志,23(3):193-202
邵济安,路凤香,张履桥,杨进辉.2005.辽西义县组玄武岩捕虏晶的发现及其意义.岩石学报,21(6):1547-1558
汤艳杰,张宏福,英基丰.2014.阴山及邻区三叠纪富碱侵入岩的成因意义.岩石学报,30(7):2031-2040
阎国翰,牟保磊,许保良,何国琦,谭林坤,赵晖,何中甫,张任祜,乔广生.2000.燕辽-阴山三叠纪碱性侵入岩年代学和Sr,Nd,Pb同位素特征及意义.中国科学(D辑),30(4):383-387
张拴宏,赵越,刘建民,胡健民,宋彪,刘健,吴海.2010.华北地块北缘晚古生代-早中生代岩浆活动期次、特征及构造背景.岩石矿物学杂志,29(6):824-842
张招崇,王永强.1997.冀北印支期碱性岩浆活动及其地球动力学意义.矿物岩石地球化学通报,16(4):214-217
郑建平,路凤香.1999.胶辽半岛金伯利岩中地幔捕虏体岩石学特征:古生代岩石圈地幔及其不均一性.岩石学报,15(1):65-74