金坛盆地云林凹陷古近系阜宁组石盐矿缺失原因研究

Causes of absence of common salt deposit in Paleogene Funing Formation of Yunlin sag in Jintan Basin

文章依据研究区内施工的二维地震勘查及钻探验证工程等相关资料,结合邻区揭露地层对比,分析了预测结果产生误差的原因,并对区域内较发育的断层对金坛盆地石盐成矿的影响进行了系统研究。结果表明单一地球物理方法勘查的不确定性,是使得预测结果产生误差的重要原因。区内DF1、DF2断层形成时间晚于阜宁组形成时间,对石盐沉积成矿不构成影响。形成于始新世―古新世F19正断层,导致位于该断层下盘的云林凹陷整体抬升,使得阜宁组含盐系地层被剥蚀,而位于该断层上盘的荣炳矿区阜宁组上段地层则发生同沉积加厚,形成石盐资源。

After comparison with exposed strata in adj acent region,this paper analyzed the cause of prediction errors and conducted systematic research on the influence of better developed faults on mineralization of com-mon salt deposit in Jintan Basin based on data related to on-going 2D seismic exploration and drilling verifica-tion proj ects.The results indicated that the uncertainty of single geophysical exploration was the main cause of prediction errors.Fault DF1 and DF2 were formed later than Funing Formation did,and they had no influ-ence on the sedimentary mineralization of common salt.Eocene-Paleocene normal fault F19 resulted in the uplift of Yunlin sag which was under the lower part of the fault,and it made the salt-bearing strata of Funing Formation suffer from denudation;upper strata of Funing Formation in Rongbing mining area which oc-curred in the upper part of the fault suffered from synsedimentary thickening and formed the resource of common salt.