盐边群构造地层特征及其大地构造意义
|
摘要
Grenville期造山带存在于中晚元古代，是连接Rodinia各陆块的纽带。扬子陆块在Rodinia中的位置是近几年来的热点问题，愈来愈多的证据显示它的褶皱基底是Grenville期造山带的重要组成部分，盐边群是扬子陆块褶皱基底的组成部分，研究它的地质特征和大地构造属性，可以为研究扬子陆块在Rodinia中的位置提供重要的地质线索。
在野外和室内仔细工作的基础上，本文在以下四个方面取得了进步：
1．基于对盐边群中、小尺度变形构造进行构造解析，建立了区域构造格架，通过对褶皱枢纽和劈理的分析，提出盐边群第一期透入性变形构造的走向为北东东—南西西向。
2．根据新的区域构造格架和野外连续露头的叠覆关系，重新厘定了盐边群碎屑岩的地层序列以及各碎屑组的内含。
3．通过岩石特征和地球化学分析，确定了盐边群荒田组火山岩组合为洋脊玄武岩、洋岛玄武岩、洋岛安山玄武岩系列，说明这是洋壳残片，即典型的蛇绿岩套。经过初步的侵位机制分析，可知这套火山岩经历了海沟增生楔、弧前盆地基底，并接受了盐边群碎屑岩的沉积。
4．盐边群碎屑岩碎屑骨架颗粒统计分析结果和砂岩常量元素构造环境判断图解显示，它们所处的构造环境为活动大陆边缘，初步判定它们的原型盆地为弧前盆地。
基于以上结论，讨论了Grenville期造山带在康滇地区存在的可能性及其可能的展布走向，进而讨论了扬子陆块在Rodinia中可能的位置。
The Grenville-aged orogen is a tie to link most of the continental blocks in Rodinia, which existed during the period from late Mesoproterozoic through early Neoproterozoic. The position of Yangtze Block in Rodinia have been warmly discussed in the recent years. More and more evidences suggest that the fold basement of Yangtze Block is an integral part of the Grenville-aged orogen. The Yanbian Group, which resulted from post-Grenville orogen, outcrops in the Panzhihua area, Sichuan province. Hence, the studies on the geological features and geotectonic implications of the Yanbian Group can provide some clues to refine the position of Yangtze Block in Rodinia.
Based on the field working and lab analysis, the following conclusions were made:
1. The anatomy of small-scale to meso-scale deformational structures have resulted in the reconstruction of the structural framework of the Yanbian Group. The statistical analyses of the fold hinge and cleavages developed in the Yanbian Group suggest the trend of the first stage penetrating structures of the Yanbian Group is EEN-WWS.
2. Based on the new structural framework and the overlap relationships in every continuous outcrop, the new stratigraphic sequence of the Yanbian Group is put forward, which deeply changes the rock composition of every formation.
3. The analysis of the geochemical and petrologic characteristics features shows that the assemblage of volcanic rocks is the series of middle ocean ridge basalt, ocean island basalt and ocean island andesite basalt, which implies that it is the relic of the ocean crust, i.e. typical ophiolites. The primitive study on the emplacement mechanism suggests that the volcanic rocks had underwent the stages of the trench accretion and the basement of forearc basin, which received the elastics of the Yanbian Group.
4. Triangular diagram of the sandstone clastic compositions and the relationship diagram of major element suggest that the proto basin of the clastic rock of the Yanbian Group was a forearc basin, which was in an active continental margin.
Based on the above conclusion, the regional expression of the Grenville-aged orogen in the Kangdian Area and orogenic architecture is also discussed, and the refining position of Yangtze Block in Rodinia is proposed
在野外和室内仔细工作的基础上，本文在以下四个方面取得了进步：
1．基于对盐边群中、小尺度变形构造进行构造解析，建立了区域构造格架，通过对褶皱枢纽和劈理的分析，提出盐边群第一期透入性变形构造的走向为北东东—南西西向。
2．根据新的区域构造格架和野外连续露头的叠覆关系，重新厘定了盐边群碎屑岩的地层序列以及各碎屑组的内含。
3．通过岩石特征和地球化学分析，确定了盐边群荒田组火山岩组合为洋脊玄武岩、洋岛玄武岩、洋岛安山玄武岩系列，说明这是洋壳残片，即典型的蛇绿岩套。经过初步的侵位机制分析，可知这套火山岩经历了海沟增生楔、弧前盆地基底，并接受了盐边群碎屑岩的沉积。
4．盐边群碎屑岩碎屑骨架颗粒统计分析结果和砂岩常量元素构造环境判断图解显示，它们所处的构造环境为活动大陆边缘，初步判定它们的原型盆地为弧前盆地。
基于以上结论，讨论了Grenville期造山带在康滇地区存在的可能性及其可能的展布走向，进而讨论了扬子陆块在Rodinia中可能的位置。
The Grenville-aged orogen is a tie to link most of the continental blocks in Rodinia, which existed during the period from late Mesoproterozoic through early Neoproterozoic. The position of Yangtze Block in Rodinia have been warmly discussed in the recent years. More and more evidences suggest that the fold basement of Yangtze Block is an integral part of the Grenville-aged orogen. The Yanbian Group, which resulted from post-Grenville orogen, outcrops in the Panzhihua area, Sichuan province. Hence, the studies on the geological features and geotectonic implications of the Yanbian Group can provide some clues to refine the position of Yangtze Block in Rodinia.
Based on the field working and lab analysis, the following conclusions were made:
1. The anatomy of small-scale to meso-scale deformational structures have resulted in the reconstruction of the structural framework of the Yanbian Group. The statistical analyses of the fold hinge and cleavages developed in the Yanbian Group suggest the trend of the first stage penetrating structures of the Yanbian Group is EEN-WWS.
2. Based on the new structural framework and the overlap relationships in every continuous outcrop, the new stratigraphic sequence of the Yanbian Group is put forward, which deeply changes the rock composition of every formation.
3. The analysis of the geochemical and petrologic characteristics features shows that the assemblage of volcanic rocks is the series of middle ocean ridge basalt, ocean island basalt and ocean island andesite basalt, which implies that it is the relic of the ocean crust, i.e. typical ophiolites. The primitive study on the emplacement mechanism suggests that the volcanic rocks had underwent the stages of the trench accretion and the basement of forearc basin, which received the elastics of the Yanbian Group.
4. Triangular diagram of the sandstone clastic compositions and the relationship diagram of major element suggest that the proto basin of the clastic rock of the Yanbian Group was a forearc basin, which was in an active continental margin.
Based on the above conclusion, the regional expression of the Grenville-aged orogen in the Kangdian Area and orogenic architecture is also discussed, and the refining position of Yangtze Block in Rodinia is proposed
引文
陈克强，汤加富，1995，构造地层单位研究．武汉：中国地质大学出版社，13-21．
陈岳龙，罗照华，刘翠，2001，对扬子克拉通西缘四川康定—冕宁变质基底的新认识—来自Nd同位素的证据．地球科学，V．26(3)，279-285．
从柏林，1979，岩浆活动与火成岩组合，科学出版社．
郭令智，施央申，1984，中国东南部地体构造研究．南京大学学报(自然科学)，20(4)：732-739．
郭令智，施央申，马瑞士，1977，论古海沟岛弧系的研方法及其意义．福建地质，(4)：1-24．
郭令智，施央申，马瑞士，1980，华南大地构造格架与地壳演化．见：26届国际交流地质学术文集，北京：地质出版社，109-116．
李继亮等，1983，四川盐边元古代蛇绿岩套的稀土元素特征．岩石学研究，(3)；37-47
卢华复，郭令智，施央申，马瑞士，1975，华南震旦纪地层与构造问题．南京大学学报(自然科学版)，11：121-136．
孙传敏，1994，四川盐边元古代蛇绿岩套中辉石的成因矿物学及其大地构造意义．矿物岩石，14(8)，1-16．
汤加富，1994，华南变质基底的组成、边界与构造演化．安徽地质，V．4(1-2)，104-111．
汤加富，1996，构造地层学的研究与应用．中国区域地质，V．2，97-107．
王鸿祯，1989，地层学的分类体系和分支学科—对修订中国地层指南的设想．地质评论，35(3)：271-276．
王五力，2000，试论构造地层学、非史密斯地层学和造山带地层学．地层学杂志，V．24，352-357．
王自强，张玲华，周洪瑞等，1991，扬子地台东南部和北部陆缘区中、晚元古代构造发展特征．见：王鸿祯主编，中国及邻区构造古地理和生物古地理，武汉：中国地质大学出版社，246-262．
吴传荣，胡立山，邓乾忠，王昌华，1995，中浅变质岩系构造地层单位基本特征及在地质制图中的运用(以武当山为例)．见：陈克强，汤加富主编，构造地层单位研究，武汉：中国地质大学出版社，73-83．
邢无京，1989，康定群的地质特征及其在扬子地台基底演化中的意义．中国区域地质，V．4，347-356．
许靖华，1980，薄壳板块构造模式与冲撞型造山运动．中国科学，(11)：1083-1089．
许志琴，候立玮，王宗秀，1992，中国松潘—甘孜造山带的造山过程．北京：地质出版社， 7-52．
张传恒，张世红，1998，弧前盆地研究进展综述．地质科技情报，V．17(4)，1-6．
张守信，1989，理论地层学——现代地层学概论．北京：科学出版社．1—34．
中国地层委员会编，1998，中国地层指南(草案)．全国地层委员会办公室印．
Brookfield, M. E., 1993, Neoproterozoic Laurentia-Australia fit. Geology, V. 21,683-686.
Dalziel, L. W. D., 1991, Pacific margins of Lautentia and East Antarctic-Australia as a conjugate riff pair: Evidence and implication for an Eocambrian supercontinent. Geology, V. 19, 598-601.
Fitzsimons, I. C. W., 2000, Grenville-age basement provinces in East Antarctica: Evidence for three separate collisional orogens. Geology, V. 28, 879-882.
Gianreto Manatschal, and Daniel Bernoulli, 1999, Architecture and tectonic evolution of
nonvolcanic margins: Present-day Galicia and ancient Adria. Tectonics, V. 18(6) , 1099-1119．
Gose, W. A., Helper, M. A., Connelly, J. N., Hutson, F. E., and Dalziel, L. W. D., 1997, Paleomagnetic data and U-Pb isotopic age determinations from Coats Land,Antarctic: Implications for late Proterozoic plate reconstructions. Journal of geophysical research, V. 102, 7887-7902．
Hoffman, P.F., 1991, Did the breakout of Laurentia rum Gondwanaland inside-out?. Science, V. 252, 1409-1411．
Hsu, K-J, Li, J., Chen, H-H., Pen, H. B., Sengor, A., 1990, Tectonics of South China: key to understanding west Pacific geology. Tectonophysics, V. 183: 9-39．
J.A.Pearce, 1982, Trace element characteristics of lavas from destructive plate boundaries. In: Thorpe,R.S.(ed.) Andesites, 525-548． John Wiley and Sons.
J.A.Pearce,S.J.Lippard & S.Roberts, 1984, Characterristics and tectonic significance of supra-subduction zone ophiolites. from: Marginal Basin Geology(Volcanic and associated sedimentary and tectonic processes in modern and ancient marginal basins),edited by:B.P.Kokelear and M.F.Howells;Geological Society Special Publication. No. 16, 77-94．
Jean-Paul Callot, Cecile Grigne, Laurent Geoffroy, and Jean-Pierre Brun, 2001, Development of volcanic passive margins: Two-dimensional laboratory models. Tectonics, V. 20, No.l, 148-159．
Karl E. Karkstrom, Stephen S. Harlan, et al. 1999, Refining Rodinia: Geologic Evidence for the Australia-Western U.S. connection in the Proterozoic. GSA today, V. 9(10) , 1-7．
Li, Z. X., Powell, C. McA., 1993, Paleomegnetic constraints on timing of the Neoproterozoic breakup of Rodinia and the Cambrian formation of Gondwana. Geology, V. 21, 889-892．
Li, Z. X., Powell, C. McA., 1993, Late Proterozoic to Early Paleozoic paleomagnetism and the formation of Gondwanaland. In: Findlay, R. H., et al, edl, Gondwana & assembly, evolution and dispersal. Rotterdam, Netherlands: A. A. Balkema, 9-21．
Li, Z. X.., 1998, Tectonic history of the major east Asian lithospheric blocks since the Mid-Proterozoic-asynthesis. In: Mantle dynamics and plate ineractions in East Asia. Geodynamics Series 27, by the American Geophysical Union, 221-244．
Li, Z. X.., Li, X. H., Kinny, P. D., Wang, J., 1999, The breakup of Rodinia: Did it start with a mantle plume beneath South China? Earth Planet Science Letters, V. 173: 171-181．
Li, Z. X., Li, X. H., Zhou, H. W., Kinny, Peter D., 2002, Grenvillian continental collision in south China: New SHRIMP U-Pb zircon results and implications for the configuration of Rodinia. Geology, V. 30(2) , 163-166．
Li, Z-X., Zhang, L., and Powell, C. McA., 1995, South China in Rodinia: Part of the missing link between Australia-East Antarctic and Laurentia: Geology, V. 23,407-410．
Li, Z-X., Zhang, L., Powell, C. McA., 1996a, Positions of the East Asian cratons in the Neoproterozoic supercontinent Rodinia. Australian journal of Earth Sciences, V. 43: 593-604．
McMenamin, M. A. S., McMenamin, D. L. S., 1990, The emergence of animals. The Cambrian breakthrough, Columbia University Press, New York.
Moores, E.M., 1991, Southwest U.S.-East Antarctic(SWEAT) Connection: Ahypothesis. Geology, V. 19,425-428．
Rainbird, R. H., Heaman, L. M., Young, G, 1992, Sampling Laurentia:Detrital zircon geochronology offers evidence for an extensive Neoproterozoic river system origination from
the Grenville orogen. Geology, V. 20, 351-354．
Rittmann, A., 1970, Note to contribution by V. Gottini on the "Serial character of the volcanic rocks of Pantelleria", Bull. Bolcanol., V. 33, 979-981．
Ross, G M., Parrisk, R., 1992, Belt Supergroup (Northwestern United States): Implications for age of deposition and prePanthalassa plate reconstructions. Earth and planetary science letters, V. 113,57-76．
Tracy D. Frank, 1998, "Molar-tooth" structure: A geochemical perpective on a Proterozoic enigma. Geology, V. 26, No.8, 683-686．
Van der Voo R., 1990, Phanerozoic paleomagnetic poles from Europe and North America and comparisons with continental reconstructions. Reviews of Geophysics, V. 28, 167-206．
陈岳龙，罗照华，刘翠，2001，对扬子克拉通西缘四川康定—冕宁变质基底的新认识—来自Nd同位素的证据．地球科学，V．26(3)，279-285．
从柏林，1979，岩浆活动与火成岩组合，科学出版社．
郭令智，施央申，1984，中国东南部地体构造研究．南京大学学报(自然科学)，20(4)：732-739．
郭令智，施央申，马瑞士，1977，论古海沟岛弧系的研方法及其意义．福建地质，(4)：1-24．
郭令智，施央申，马瑞士，1980，华南大地构造格架与地壳演化．见：26届国际交流地质学术文集，北京：地质出版社，109-116．
李继亮等，1983，四川盐边元古代蛇绿岩套的稀土元素特征．岩石学研究，(3)；37-47
卢华复，郭令智，施央申，马瑞士，1975，华南震旦纪地层与构造问题．南京大学学报(自然科学版)，11：121-136．
孙传敏，1994，四川盐边元古代蛇绿岩套中辉石的成因矿物学及其大地构造意义．矿物岩石，14(8)，1-16．
汤加富，1994，华南变质基底的组成、边界与构造演化．安徽地质，V．4(1-2)，104-111．
汤加富，1996，构造地层学的研究与应用．中国区域地质，V．2，97-107．
王鸿祯，1989，地层学的分类体系和分支学科—对修订中国地层指南的设想．地质评论，35(3)：271-276．
王五力，2000，试论构造地层学、非史密斯地层学和造山带地层学．地层学杂志，V．24，352-357．
王自强，张玲华，周洪瑞等，1991，扬子地台东南部和北部陆缘区中、晚元古代构造发展特征．见：王鸿祯主编，中国及邻区构造古地理和生物古地理，武汉：中国地质大学出版社，246-262．
吴传荣，胡立山，邓乾忠，王昌华，1995，中浅变质岩系构造地层单位基本特征及在地质制图中的运用(以武当山为例)．见：陈克强，汤加富主编，构造地层单位研究，武汉：中国地质大学出版社，73-83．
邢无京，1989，康定群的地质特征及其在扬子地台基底演化中的意义．中国区域地质，V．4，347-356．
许靖华，1980，薄壳板块构造模式与冲撞型造山运动．中国科学，(11)：1083-1089．
许志琴，候立玮，王宗秀，1992，中国松潘—甘孜造山带的造山过程．北京：地质出版社， 7-52．
张传恒，张世红，1998，弧前盆地研究进展综述．地质科技情报，V．17(4)，1-6．
张守信，1989，理论地层学——现代地层学概论．北京：科学出版社．1—34．
中国地层委员会编，1998，中国地层指南(草案)．全国地层委员会办公室印．
Brookfield, M. E., 1993, Neoproterozoic Laurentia-Australia fit. Geology, V. 21,683-686.
Dalziel, L. W. D., 1991, Pacific margins of Lautentia and East Antarctic-Australia as a conjugate riff pair: Evidence and implication for an Eocambrian supercontinent. Geology, V. 19, 598-601.
Fitzsimons, I. C. W., 2000, Grenville-age basement provinces in East Antarctica: Evidence for three separate collisional orogens. Geology, V. 28, 879-882.
Gianreto Manatschal, and Daniel Bernoulli, 1999, Architecture and tectonic evolution of
nonvolcanic margins: Present-day Galicia and ancient Adria. Tectonics, V. 18(6) , 1099-1119．
Gose, W. A., Helper, M. A., Connelly, J. N., Hutson, F. E., and Dalziel, L. W. D., 1997, Paleomagnetic data and U-Pb isotopic age determinations from Coats Land,Antarctic: Implications for late Proterozoic plate reconstructions. Journal of geophysical research, V. 102, 7887-7902．
Hoffman, P.F., 1991, Did the breakout of Laurentia rum Gondwanaland inside-out?. Science, V. 252, 1409-1411．
Hsu, K-J, Li, J., Chen, H-H., Pen, H. B., Sengor, A., 1990, Tectonics of South China: key to understanding west Pacific geology. Tectonophysics, V. 183: 9-39．
J.A.Pearce, 1982, Trace element characteristics of lavas from destructive plate boundaries. In: Thorpe,R.S.(ed.) Andesites, 525-548． John Wiley and Sons.
J.A.Pearce,S.J.Lippard & S.Roberts, 1984, Characterristics and tectonic significance of supra-subduction zone ophiolites. from: Marginal Basin Geology(Volcanic and associated sedimentary and tectonic processes in modern and ancient marginal basins),edited by:B.P.Kokelear and M.F.Howells;Geological Society Special Publication. No. 16, 77-94．
Jean-Paul Callot, Cecile Grigne, Laurent Geoffroy, and Jean-Pierre Brun, 2001, Development of volcanic passive margins: Two-dimensional laboratory models. Tectonics, V. 20, No.l, 148-159．
Karl E. Karkstrom, Stephen S. Harlan, et al. 1999, Refining Rodinia: Geologic Evidence for the Australia-Western U.S. connection in the Proterozoic. GSA today, V. 9(10) , 1-7．
Li, Z. X., Powell, C. McA., 1993, Paleomegnetic constraints on timing of the Neoproterozoic breakup of Rodinia and the Cambrian formation of Gondwana. Geology, V. 21, 889-892．
Li, Z. X., Powell, C. McA., 1993, Late Proterozoic to Early Paleozoic paleomagnetism and the formation of Gondwanaland. In: Findlay, R. H., et al, edl, Gondwana & assembly, evolution and dispersal. Rotterdam, Netherlands: A. A. Balkema, 9-21．
Li, Z. X.., 1998, Tectonic history of the major east Asian lithospheric blocks since the Mid-Proterozoic-asynthesis. In: Mantle dynamics and plate ineractions in East Asia. Geodynamics Series 27, by the American Geophysical Union, 221-244．
Li, Z. X.., Li, X. H., Kinny, P. D., Wang, J., 1999, The breakup of Rodinia: Did it start with a mantle plume beneath South China? Earth Planet Science Letters, V. 173: 171-181．
Li, Z. X., Li, X. H., Zhou, H. W., Kinny, Peter D., 2002, Grenvillian continental collision in south China: New SHRIMP U-Pb zircon results and implications for the configuration of Rodinia. Geology, V. 30(2) , 163-166．
Li, Z-X., Zhang, L., and Powell, C. McA., 1995, South China in Rodinia: Part of the missing link between Australia-East Antarctic and Laurentia: Geology, V. 23,407-410．
Li, Z-X., Zhang, L., Powell, C. McA., 1996a, Positions of the East Asian cratons in the Neoproterozoic supercontinent Rodinia. Australian journal of Earth Sciences, V. 43: 593-604．
McMenamin, M. A. S., McMenamin, D. L. S., 1990, The emergence of animals. The Cambrian breakthrough, Columbia University Press, New York.
Moores, E.M., 1991, Southwest U.S.-East Antarctic(SWEAT) Connection: Ahypothesis. Geology, V. 19,425-428．
Rainbird, R. H., Heaman, L. M., Young, G, 1992, Sampling Laurentia:Detrital zircon geochronology offers evidence for an extensive Neoproterozoic river system origination from
the Grenville orogen. Geology, V. 20, 351-354．
Rittmann, A., 1970, Note to contribution by V. Gottini on the "Serial character of the volcanic rocks of Pantelleria", Bull. Bolcanol., V. 33, 979-981．
Ross, G M., Parrisk, R., 1992, Belt Supergroup (Northwestern United States): Implications for age of deposition and prePanthalassa plate reconstructions. Earth and planetary science letters, V. 113,57-76．
Tracy D. Frank, 1998, "Molar-tooth" structure: A geochemical perpective on a Proterozoic enigma. Geology, V. 26, No.8, 683-686．
Van der Voo R., 1990, Phanerozoic paleomagnetic poles from Europe and North America and comparisons with continental reconstructions. Reviews of Geophysics, V. 28, 167-206．
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |