| On the basis of the data of regional unconformities in Xinlu area, 4 synthems are defined, they are following: pre-Cretaceous, Jiandeian, Qujiangian, and Quaternary. From Middle Proterozoic to Paleogene, 4 tectonic stages are divided, i.e. Pre-Cretaceous, Jiandeian(early phase of Early Cretaceous), Qujiangian(from latter part of Early Cretaceous to Paleocene), and Eocene-Oligocene. According to the rock deformations including conjugate shear joints and so on, the author researched the characteristics of the tectonic stress field from Cretaceous to Oligocene. The maximum principal compressive stress directions respectively were NW-SE in Jiandeian stage,NNE-SSW in Qujiangian stage, and near E-W in Eocene-Oligocene stage.Adopting the method of dislocation density of quartz, the paleo-stress values in Jiandeian stage were estimated. Using the method of mathematical modeling, the tectonic stress field in Jiandeian stage was better returned. The characteristics of magmatic activity was discussed in Early Cretaceous. In the respects of geotectonic location, volcanic eruption feature, volcanic rock type, tectonic condition and so forth, the Jiandeian volcanic rocks were on intimate terms with the mineralization of uranium.The author expounded the evolutionary process of the volcano-basement structure, the relations of the tectonic stress field and the structural evolution from Early Cretaceous to Oligocene, and the stages and the assemblages of the faulted structures.The author discussed the relationship of the tectonic stress field with the mineralization of uranium from Early Cretaceous to Oligocene. Under the actions of the the tectonic stress fields in Jiandeian and qujiangian stage, the fractures developed or again moved, thus the structures of the fluid passageway and housing for the uranium ore were formed. The intensity of the tectonic activity in Eocene-Oligocene stage clearly weaken; the uranium deposits were lightly destroyed or transformed thereby.
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