倒楔运动与汶川特大地震的成因
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摘要
汶川特大地震的构造背景是"两堑夹一垒".中生代以来,龙门山倒楔顺行,由地垒发展成横弯背斜;其东侧的正硬楔下降,仍然是地堑,形成了四川盆地;其西侧的正硬楔上部演化成软楔,软楔运动造山,形成了松潘-甘孜高原.伴随楔块运动,主要来自于四川盆地正硬楔底部的富含挥发组分的岩浆,在茶坪山、龙门山等背斜圈闭内大量聚集.当圈闭内的流体能够冲破盖层时,便发生隐爆,形成了5.12汶川特大地震和余震及其山崩地裂等地质现象.
The tectonic background of the devastating earthquake in Wenchuan is"one horst trapped between two grabens ".Since the beginning of the Mesozoic era,the Longmen Moutain inverted wedge block kept direct motion as a horst and formed a cross-bend anticline.Whilst the upright hard-wedge in the east declined and also is a graben that formed the Sichuan Basin.The upright hard-wedge in the west became soft-wedge and then formed the Songpan-Ganzi plateau.Accompanied with the wedge block movement.The magma,which is characterized by abundance volatile composition at the bottom of the upright hard wedge in the Sichuan Basin,assembled in the anticline trap of Chaping and Longmen mountains.When such fluid in the anticline trap can break through the overlying strata,the occult explosion would occur and the fluid released.These factors might cause the 5.12 Wenchuan earthquake and related aftershock,the mountains fall and Earth splits as well as other geological phenomena.
The tectonic background of the devastating earthquake in Wenchuan is"one horst trapped between two grabens ".Since the beginning of the Mesozoic era,the Longmen Moutain inverted wedge block kept direct motion as a horst and formed a cross-bend anticline.Whilst the upright hard-wedge in the east declined and also is a graben that formed the Sichuan Basin.The upright hard-wedge in the west became soft-wedge and then formed the Songpan-Ganzi plateau.Accompanied with the wedge block movement.The magma,which is characterized by abundance volatile composition at the bottom of the upright hard wedge in the Sichuan Basin,assembled in the anticline trap of Chaping and Longmen mountains.When such fluid in the anticline trap can break through the overlying strata,the occult explosion would occur and the fluid released.These factors might cause the 5.12 Wenchuan earthquake and related aftershock,the mountains fall and Earth splits as well as other geological phenomena.
引文
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[4]刘斌夫.中国跨领域科学研究前卫学者首度解读汶川地震深层原因,2008-5-19发布.来源:新浪网.
[5]白思胜,张佐堂.论楔块运动与地震带的关系[J].灾害学,2006,21(3):85-87.
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[8]刘启元,陈九辉,李顺成,等.汶川8.0级地震:川西流动地震台阵观测数据的初步分析[J].地震地质,2008,30(3):584-596.
[2]张国民,邵志刚,刘桂萍,等.汶川8.0级地震构造动力成因分析[J].地震,2009,29(1):164-173.
[3]张培震.详解汶川大地震特征与成因.2008-6-27发布.来源:新华网.
[4]刘斌夫.中国跨领域科学研究前卫学者首度解读汶川地震深层原因,2008-5-19发布.来源:新浪网.
[5]白思胜,张佐堂.论楔块运动与地震带的关系[J].灾害学,2006,21(3):85-87.
[6]白思胜.倒楔运动与海原特大地震的关联性研究[J].宁夏师范学院学报,2010(5):57-61.
[7]张景廉,杜乐天,张虎权,等.汶川大地震与中地壳低速、高导层的成因关系初探[J].西北地震学报,2008,30(4):406-411.
[8]刘启元,陈九辉,李顺成,等.汶川8.0级地震:川西流动地震台阵观测数据的初步分析[J].地震地质,2008,30(3):584-596.
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