汤原断陷古近系宝泉岭组沉积特征及其对铀成矿作用的制约

本文以汤原断陷古近系宝泉岭组为主要研究目标层位,开展了沉积岩石学特征、古沉积环境特征、沉积体系特征及层间氧化带发育特征等方面的研究,探讨了宝泉岭组发育特征及其对铀成矿作用的制约。研究认为:(1)宝泉岭组砂岩类型主要为长石岩屑杂砂岩和岩屑砂岩,岩石具典型的低成分成熟度、低结构成熟度特征,具有近物源搬运的特征；(2)古近系宝泉岭组沉积时期为陆相淡水环境,古气候表现为温湿—干热气候,地球化学环境表现为还原环境,具较高的还原容量,有利于铀元素的还原沉淀；(3)宝泉岭组发育扇三角洲相,主要砂体表现为分流河道和水下分流河道两类,其中分流河道砂体应作为研究区下一步砂岩型铀矿找矿的主攻砂体类型。

Sedimentary characteristics of Paleogene Baoquanling Formation in Tangyuan fault depression and its constraints on uranium mineralization

In the paper, sedimentary petrological characteristics, paleosedimentary environment characteristics, sedimentary system characteristics, and interlayer oxidation zone development characteristics of the Paleogene Baoquanling Formation have been studied, the developmental characteristics of the Baoquanling Formation and its constraints on uranium mineralization have been discussed. Research suggests that:(1)The sandstone types of the Baoquanling Formation are mainly feldspathic lithic greywacke and lithic sandstone. The rocks have typical characteristics of low compositional maturity and low structural maturity, and are characterized by near source transport; (2) The Paleogene Baoquanling Formation was deposited in a continental freshwater environment, with a paleoclimate characterized by a warm humid dry hot climate, and a geochemical environment characterized by a reduction environment with high reduction capacity, which is conducive to the reduction and precipitation of uranium elements; (3) The Baoquanling Formation develops fan delta facies, and the main sand bodies are divided into two types:distributary channels and underwater distributary channels. The distributary channel sand bodies should be the main type of sand bodies for the next exploration of sandstone type uranium deposits in the study area.