宁夏香山群为一套遭受轻微区域变质的陆源碎屑岩,并夹有少量碳酸盐岩和硅质岩,属于深水浊流沉积,从下到上可分为徐家圈组、狼嘴子组和磨盘井组.长期以来对香山群的研究主要集中在时代探讨上,而在其他方面较薄弱.本文以徐家圈组为主要研究对象,从浊积砂岩的碎屑颗粒类型百分含量、常量元素和微量元素等方面对其沉积时的大地构造环境进行了综合研究.结果表明:碎屑颗粒类型显示出典型的被动大陆边缘;常量元素的判别则出现了不确定性;微量元素则显示出了过渡性质.因此,香山群徐家圈组沉积时大地构造环境可能不是简单的被动大陆边缘,其物源极有可能来自被动大陆边缘、活动大陆边缘和大陆岛弧之间的带有过渡性质的源区.%The Xiangshan Group in Ningxia is dominated by deep-water turbidity current deposits which are mainly a set of low metamorphic terrigenous clastic rocks intercalated with minor carbonate rocks and cherts.The Xiangshan Group is divided into three formations.which are from bottom to top Xujiajuan Formation, Langzuizi Formation and Mopanjing Formation.As relatively much research work was devoted to the formation epoch while the study of other aspects was insufficient in the past, the authors have made an integrated study of tectonic settings from the framework modes, major elements and trace elements of terrigenous sandstones in Xujiajuan Formation, which comprises the lower part of Xiangshan Group.Some conclusions have been reached: ① the framework modes suggest a typical passive margin; ② the discrimination diagrams for major elements suggest a result of uncertainty; and ③the discrimination diagrams for trace elements suggest a transition tectonic setting.Thus, the tectonic setting during the deposition of Xujiajuan Formation of Xiangshan Group was not a simple passive margin, but most probably a transition source area among the passive margin, the active margin and the continental island arc.
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