准噶尔盆地南缘构造抬升剥蚀不均一性对砂岩型铀矿的制约

发布时间：2018-06-21 15:06

本文选题：准噶尔盆地南缘 + 镜质体反射率　；参考：《大地构造与成矿学》2017年05期

【摘要】：准噶尔盆地南缘与伊犁和吐哈典型产铀盆地成矿地质背景相似,然而,至今未发现铀矿床。现存铀矿(化)点主要受控于构造形态和抬升剥蚀程度,本文主要通过恢复准噶尔盆地南缘构造抬升剥蚀量,探讨构造抬升剥蚀不均一性对砂岩型铀成矿的制约,指出有利构造保矿的适宜地段。采用镜质体反射率(Ro)反演技术,结合目的层成岩作用研究,估算出四棵树和硫磺沟地区剥蚀量分别为2880~3680 m和2400~3680 m,相对较小。分析抬升剥蚀不均一性的形成机制发现,两个地区发育走滑断层主导的传递带致使抬升剥蚀量相对较小,主要表现为地层的逆冲缩量相对较小和发育不同的构造调节方式(盆山耦合方式)。四棵树地区主要发育逆掩冲断型盆山耦合方式,对后期铀成矿不利;硫磺沟地区发育冲隆-掀斜型盆山耦合方式,对铀成矿的保存较为有利。地表露头和深部钻孔均显示硫磺沟地区存在层间氧化带及其铀矿体的可能,是寻找剥蚀残留"古矿"的优选地段。
[Abstract]:The southern margin of Junggar Basin is similar to the typical uranium-producing basins in Yili and Tuha. However, no uranium deposits have been found so far. The existing uranium ore (mineralization) points are mainly controlled by the structural morphology and the degree of uplift and denudation. By restoring the amount of tectonic uplift and denudation in the southern margin of Junggar Basin, the constraints of structural uplift and denudation heterogeneity on sandstone-type uranium mineralization are discussed in this paper. It is pointed out that the favorable structure is suitable for ore preservation. By using vitrinite reflectance Ro) inversion technique and combined with the diagenesis study of the target layer, the denudation amounts of four trees and sulfur trenches are estimated to be 2880 ~ 3680 m and 2400 ~ 3680 m respectively, which are relatively small. By analyzing the formation mechanism of the inhomogeneity of uplift and denudation, it is found that the amount of uplift and denudation is relatively small due to the transfer zone dominated by strike-slip faults in the two regions. The main features are the relatively small thrusting volume of strata and the development of different structural adjustment modes (basin-mountain coupling mode). The coupling mode of thrust basin and mountain is mainly developed in Sikeshu area, which is unfavorable to uranium mineralization in late stage, and the coupling mode of chong uplift and tilting basin and mountain is developed in sulfur ditch area, which is favorable for the preservation of uranium mineralization. Both surface outcrop and deep borehole indicate the existence of interlayer oxidation zone and the possibility of uranium orebody in the Sulphulangou area, which is an optimal site for searching for "ancient ore" of denudation residue.
【作者单位】：核工业北京地质研究院;中国地质大学(北京)地球科学与资源学院;
【基金】：准噶尔盆地核能开发项目国家重点基础研究发展计划“973”项目(2015CB453004) 国防预研项目(3210402)联合资助
【分类号】：P619.14

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