SANDSTONE COMPOSITIONS AND PALEOGEOGRAPHIC EVOLUTION OF THE UPPER TRIASSIC XUJIAHE FORMATION IN THE WESTERN SICHUAN BASIN, CHINA
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摘要: 以四川盆地西部上三叠统须家河组的砂岩组分为基础,详细分析该期研究区古地理的演化。在现有分层的基础上,按照Gazzi-Dickinson计点法,对研究区上三叠统须家河组的砂岩薄片进行统计、分析,并根据Dickinson等人的研究思路,对各段砂岩作以QmFLt, QpLvLs为端元成分的砂岩三角投影图。结果表明:在QmFLt图上,砂岩投点从须二段开始落于过渡再旋回和岩屑再旋回分区上,须三、须四段投点结果更加明显;在QpLvLs图上,砂岩投点也是从须二段开始落于褶皱—逆掩带分区上的,到须三、须四段投点结果也更加明显。结合研究区的沉积相特征,分析表明:龙门山逆冲带在须二期开始了逆冲推覆,并开始为研究区提供了沉积物质,研究区也从须二期开始演化形成川西前陆盆地;须三期,龙门山逆冲推覆体进一步强烈的运动,并开始成为研究区的主要物源区;须四期,受安县运动的影响,龙门山逆冲推覆体褶皱成山,研究区真正进入了以陆相沉积环境为主的演化期。Abstract: Based on the sandstone compositions analysis of the Upper Triassic Xujiahe Formation in Western Sichuan Basin,the authors tried to discuss the paleogeographic evolution of the study area.According to the current stratigraphic division,sandstone-chips were counted and analyzed with the Gazzi-Dickinson point-counting method.And the QmFLt & the QpLvLs triangular diagrams were established from Dickinson's research ideas.The triangular QmFLt plot show that sandstone compositions began locating Transitional Recycled Provenance and Lithic Recycled Provenance in the second section of the Xujiahe Formation (T3x2),and the results were more obvious in the third and fourth sections of the Xujiahe Formation (T3x3 and T3x4).The triangular QpLvLs plot show that sandstone compositions began locating Fold-Thrust Provenance in the second section (T3x2),and the results were also more obvious in the third and fourth sections (T3x3 and T3x4).Combined with sedimentary facies of the Xujiahe Formation in the study area,it was indicated that Longmenshan thrust belt began uplifting and providing the sediment in the second section (T3x2),and West Sichuan Foreland Basin began developing in the second section (T3x2);In the third section (T3x3),the Longmenshan thrust belt took place strongly uplifted and became the primary provenance area.Because of influence by the An'xian movement in the forth section (T3x4),the Longmenshan thrust belt uplifted and became a mountain which really changed the study area into terrestrial sedimentary environment.
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[1] 罗志立.龙门山造山带岩石圈演化的动力学模式[J].成都地质学院学报,1991,18(1):1～7. [2] 邓康龄.四川盆地形成演化与油气勘探领域[J].天然气工业,1992,12(5):7～12. [3] 刘树根.龙门山冲断带与川西前陆盆地的形成演化[M].成都:成都科技大学出版社,1993.1～167. [4] 李勇,曾允孚,伊海生.龙门山前陆盆地沉积及构造演化[M].成都:成都科技大学出版社,1995.1～92. [5] 刘树根,童崇光,罗志立等.川西晚三叠世前陆盆地的形成与演化[J].天然气工业,1995,15(2):11～15. [6] 颜仰基,吴应林.巴颜喀拉—川西边缘前陆盆地演化[J].岩相古地理,1996,16(3):16～29. [7] 郭正吾,邓康龄,韩永辉.四川盆地形成与演化[M].北京:地质出版社,1996.1～200. [8] 刘树根,罗志立,赵锡奎等.龙门山造山带—川西前陆盆地系统形成的动力学模式及模拟研究[J].石油实验地质,2003,25(5):432～438. [9] 贾东,陈竹新,贾承造等.龙门山前陆褶皱冲断带构造解析与川西前陆盆地的发育[J].高校地质学报,2003,9(3):402～410. [10] 胡晓强,陈洪德,纪相田等.川西前陆盆地侏罗系三角洲沉积体系与沉积模式[J].石油实验地质,2005,27(3):226～231. [11] 四川盆地陆相中生代地层古生物编写组.四川盆地陆相中生代地层古生物[M].成都:四川人民出版社,1984.1～622. [12] 林良彪.川西前陆盆地上三叠统须家河组沉积相及岩相古地理演化[D]:[学位论文].成都:成都理工大学,2005. [13] Dickinson W R,Suczek C C.Platetectonics and sandstone compositions[J].AAPG Bulletin,1979,63:2164～2182. [14] Dickinson W R,Beard L S,Brakenridge G R,et al.Provenance of North American Phanerozoic sandstones in relation to tectonic setting[J].GSA Bulletin,1983,94:222～235. [15] Dickinson W R.Interpreting provenance relations from detrital modes of sandstones[A].In:Zuffa G G,ed.Provenance of Arenites[M].Dordrecht:Reidel Publishing Co,1985.333～361. [16] Ingersoll R V,Bullard T F,Ford R L.The effect of grain size on detrital modes:a test of the Gazzi-Dickinson point-counting method[J].Journal of Sedimentary Petrology,1984,54:103～116. [17] 李叔兵,何鲤,柳梅青.四川盆地晚三叠世以来陆相盆地演化史[J].天然气工业,1999.19(增刊):18～23. [18] 汪泽成,赵文智,张林等.四川盆地构造层序与天然气勘探[M].北京:地质出版社,2002.1～287. [19] 邓康龄.四川盆地西部上三叠统岩相及其与油气关系的探讨[A].石油普查勘探局编.石油地质文集(7)沉积相[C],北京:地质出版社,1983.150～159. [20] 赵玉光,肖林萍.龙门山中生代前陆盆地时间地层格架及其盆地生长的动态模型研究[J].四川地质学报,1994,14(3):217～224. [21] 崔秉荃,龙学明,李元林.川西坳陷的沉降与龙门山的崛起[J].成都地质学院学报,1991,18(1):39～45. -
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