摘要
在分析前人对鄂尔多斯盆地东北部铀成矿模式研究的基础之上,对该区铀成矿控矿规律进行了详细研究,提出了鄂尔多斯盆地东北部4阶段铀成矿模式,即:①潜水氧化板状矿体形成阶段(中侏罗世直罗晚期);②早期层间氧化作用及主要卷状矿体形成阶段(中侏罗世直罗期末—早白垩世伊金霍洛初期);③油气还原保矿阶段(早白垩世伊金霍洛期末—东胜期初);④晚期层间氧化铀矿体改造叠加阶段(中新世至今)。指出研究区存在2期古层间氧化带和1期新层间氧化带砂岩型铀矿床,当各期层间氧化带相互叠合时,矿化明显加大变富,并认为研究区有利远景地段位于直罗组下段古河道两侧及下游迎水面一带,断层发育地段也是铀矿找矿的重点部位。
The complexity, diversity and imperfect comparability of metallogenic characteristics result in the situation that the same metallogenic conditions may not form completely identical ore deposits, and a metallogenic model based on one deposit does not have sufficient representativeness. Therefore, in prognosis and evaluation of different ore deposits in different areas, relevant metallogenic models should be established. Based on previous researches on the metallogenic model for sandstone-hosted uranium deposits in northeastern Ordos Basin, the authors studied in detail the uranium mineralization and ore-controlling regularities of that area. A four-phase uranium metallogenic model has thus been established： ① the formation of tabular ore bodies of phreatic oxidation zone （late Zhiluo epoch in middle Jurassic）, ② the interlayer oxidation in the early stage and the formation of major roll-front ore bodies （late Zhiluo epoch in middle Jurassic to early Yijinhuoluo epoch in early Cretaceous）, ③ oil and gas reduction and ore preservation （late Yijinhuoluo ,epoch to early Dongsheng epoch in early Cretaceous）, and ④the transformation and superposition of ore bodies of the interlayer oxidation zone in the late stage （Miocene to the present）. Studies show that there exist two stages of old interlayer oxidation zone and one stage of new interlayer oxidation zone in the study area, and that where two or three interlayer oxidation zones exist in the same place, the uranium ore body usually becomes large and rich. It is hence held that prospective areas seem to be such places as both sides of the paleo-river course of Zhiluo Formation, the upward position where groundwater meets, and the sectors of well-developed faults.
出处
《矿床地质》
CAS
CSCD
北大核心
2008年第3期415-422,共8页
Mineral Deposits
基金
国防科学技术委员会核能开发二期和国家“973”项目(编号2003CB2146)共同资助成果
关键词
地质学
鄂尔多斯盆地
砂岩型铀矿
成矿模式
层间氧化带
远景评价
geology, Ordos Basin, sandstone-type uranium deposit, metallogenic model, interlayer oxidation zone, prospective evaluation
