The Paleoproterozoic Xionger Group is widely exposed in the Xionger—Zhongtiao aulacogen (failed rift) in the southern margin of the North China craton. It records the most intense magmatism after the formation of the crystalline basement of the North China craton. The Xionger Group is occupied by volcanic lavas as well as minor sedimentary rocks and volcanic clastic rocks (4.3% in thickness). The sedimentary rocks occur as interbeds in the Dagushi and Majiahe Formations of the Xionger Group. Writers studied the sedimentary and geochemical characteristics of the siliciclastic rocks from the Dagushi Formation, in an attempt to elucidate the tectonic setting of the North China craton during the Paleoproterozoic. The Dagushi Formation contains conglomerate, sandstone, and mudstone, and could have been formed in fluvial and lacustrine environments. From bottom to top of the Dagushi Formation, the trace element contents (Sr, Ga, V) and ratios (Sr/Ba, Th/U, Zr/Rb) of the mudstone rocks reflected mainly a continental environment. But the later sequences indicate transgression, either due to basin subsidence or glacioeustasy. The compositions and their ratios of the major and trace elements of the mudstone rocks demonstrate that a derivation from main silicic source rocks and mixing a further higher proportion of mafic component. These siliciclastic rocks were derived mainly from the Archean and minor from Paleoproterozoic in the southern margin of the North China craton. The chemical index of alteration (CIA) indicates an intermediate degree of weathering. The clastic sedimentary rocks were deposited in a passive margin setting. The volcanic rocks of the Xionger Group formed in a continentalrift setting in passive continental margin.