北山地区位于华北板块、塔里木板块和哈萨克斯坦板块交汇带,晚古生代构造演化倍受关注且久有争议,该地区晚古生代地层的研究对探讨大地构造演化具有重要意义.利用同位素定年、沉积相分析、粒度分析和碎屑成分统计分析方法对北山地区早石炭世红柳园组进行研究.在下部火山岩中获得LA-ICP-MS锆石U-Pb年龄为359.9±1.4 Ma,参考区域古生物资料,其形成时代应为早石炭世早期.红柳园组上部碎屑岩中发育大量浊流沉积构造和典型鲍马序列,其中砂岩成熟度较低,并且粒度分析结果显示具有浊流沉积的粒度特征,这些证据共同指示红柳园组为近物源浊流沉积.此外通过碎屑组分统计和Qt-F-L、Qm-F-Lt以及Qp-Lv-Ls图解对沉积构造背景进行了探讨,发现研究区红柳园组物源主要来自火山弧,表明其形成的构造环境应为与岛弧邻近的沉积盆地.%The Beishan orogenic belt is the juncture area of Paleozoic Kazakstan Plate, Tarim Plate and North China Plate.Much remains to be discovered concerning the Late Paleozoic evolution in Beishan area.Therefore, the study on Late Paleozoic stratigraphy is of great importance to reveal the tectonic evolution.Hongliuyuan Formation was studied by isotopic dating,sedimentary facies analysis, grain size analysis and statistical analysis of detrital components in this paper.The LA-ICP-MS zircon U-Pb age of the volcanic rock at the bottom of Hongliuyuan Formation was 359.9±1.4 Ma, refering to regional paleontological data, which belong to the Early Carboniferous.Clastic sediments in the upper developed a large number of turbidite sedimentary structures and typical Bouma sequence, sandstone maturity was much lower, and the results of grain size analysis showed the grain size characteristics of turbidite deposition, which jointly suggest that Hongliuyuan Formation should belong to near provenance turbidite.In addition, statistics of detrital components, Qt-F-L, Qm-F-Lt and Qp-Lv-Ls diagram were used to study sedimentary tectonic background.The results showed that sedimentary provenance of Hongliuyuan Formation in Suanjingzi area are mainly from volcanic arc, and its tectonic setting should be the sedimentary basin adjacent to island arc.
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