Abstract:Conglomerate of Laiyang group in Linsishan formation developed in Songjiagou gold deposit in Muping district in Yantai city of Shandong province. The conglomerate in this group has poor soring. There are not only nearly elliptic conglomerate with High grinding roundness, but also sharp conglomerate with no grinding roundness. It reflects the complexity of the conglomerate source area. In this paper, through analysis on zircon U-Pb ages of the debris in the conglomerate, it is determined that the zircon U-Pb ages of debris are 640~770Ma, 540~570Ma and 228±4Ma respectively. Through analysis on these age periods, it is indicated that Neoproterozoic granitic gneiss rock, the rock in Sinian era, Liulinzhuang sequence extrusive rocks may be the source rocks. According to the analysis on the outcropping of such rocks in the study area, two results are obtained from near source and long distance transport deposition. Comparing with previous achievements, it is concluded that the conglomerate source area is Sulu orogenic belt. It is showed that at the beginning of the formation of Jiaolai basin, the source area of the northeastern margin was dominated by Sulu orogenic belt. This understanding is of great significance to the study of geological events in different periods of the orogenic belt in Jiaodong area.
