黑龙江省三江盆地砂岩型铀矿找矿方向探讨

三江盆地是我国黑龙江省东北部重要的中—新生代盆地。本文从三江盆地铀源条件、中—新生代构造演化、构造格局、中—新生代古气候演化、主要盖层沉积建造特征及后生蚀变特征等方面进行研究，以砂岩型铀矿成矿理论为指导，对三江盆地砂岩型铀矿成矿条件进行了综合分析，在此基础上对盆地找矿方向进行了探讨。研究认为：盆地西部具有较好的铀源条件，好于盆地其他地段；盆地中生代以来存在早白垩世末—晚白垩世早期和古近纪末—新近纪早期两期构造反转，在构造反转作用的控制下形成了盆地的主要找矿目标层下白垩统猴石沟组和古近系宝泉岭组含煤碎屑岩；猴石沟组、宝泉岭组及富锦组在盆地内发育有良好的地层结构和岩性岩相条件，同时在局部地区发育有氧化带，其是砂岩型铀矿找矿的重要线索。盆地砂岩型铀成矿条件总体较好，其中西部坳陷为重点工作区，猴石沟组和宝泉岭组为重点找矿层位。

Discussion on Prospecting Direction of Sandstone-Type Uranium Deposits in Sanjiang Basin,Heilongjiang Province

Sanjiang basin is an important Mesozoic-Cenozoic basin in northeastern Heilongjiang Province. Based on the study of the uranium source conditions, Mesozoic-Cenozoic tectonic evolution, tectonic framework, Mesozoic-Cenozoic paleoclimate evolution, the sedimentary formation characteristics of the main caprock and the epigenetic alteration characteristics, the metallogenic conditions of the sandstone-type uranium deposits in Sanjiang basin is comprehensively analyzed under the guidance of the metallogenic theory of sandstone-type uranium deposits, and the prospecting direction of the basin is discussed. It is concluded that the uranium source conditions in the western part are better than those of other parts of the basin;Since the Mesozoic, two stages of tectonic inversion occurred from the end of the Early Cretaceous to the end of the Late Cretaceous and from the end of Paleogene to the Early Neogene. Under the control of the tectonic reversal, the coal-bearing clastic rocks of the Lower Cretaceous Houshigou Formation and Paleogene Baoquanling Formation are the main target strata for prospecting in the basin;The Lower Cretaceous Houshigou Formation and Paleogene Baoquanling Formation have good stratigraphic structure, lithologic and lithofacies with oxidized zones developed in the local area, which are important clues for finding sandstone-type uranium deposits;The metallogenic conditions of the sandstone-type uranium in the basin are generally better. The western depression should be the key area of exploration, while the Lower Cretaceous Houshigou Formation, Paleogene Baoquanling Formation and Neogene Fujin Formation should be the key horizons for prospecting.