【摘要】 本文以16口钻井资料为基础,通过井震联合标定解释,获取累计5595km二维地震剖面的速度等特征物性参数,利用变速成图方法,初步编制出陕北奥陶纪盐盆主要含钾层段——马家沟组五段六亚段盐系等厚图,并进行相应的构造分异解析。提出在陕北盐盆奥陶系马家沟组五段六亚段沉积期,盆底总体表现为"两坳夹一隆"的构造样式,其中厚度大于150m的成盐凹陷主要有5个。西部盐坳的发现、东二盐凹被进一步分解为东、西2个次级盐洼、以及"两坳夹一隆"构造样式的提出,系本次研究取得的新进展和认识,表明陕北盐盆并非是一个"平底锅",其内部存在多个受同沉积断裂控制的、相对活动的次级盐凹,这些次级盐凹将有利于富钾卤水的汇聚,为可能的大规模海相钾盐成矿提供了足够的可容空间和有利的构造区位。更多还原

【Abstract】 Based on drilling data of 16 wells and integrated calibration interpretation of seismic data,the characteristic parameters(e.g.velocity) of the 2D seismic profiles with a total length of 5000 km were obtained.Using the variable velocity mapping method,the isopach map of the saliferous strata of the O2m65,which are the main potash rich strata in the Ordovician northern Shaanxi salt basin,was preliminarily worked out,and the tectonic differentiation in this region was also discussed.In the O2m65 stage of Ordovician period,the northern Shaanxi salt basin showed the tectonic pattern of "two depressions and one lifting",and there were five salt sags with the thicknesses of more than 150 meters in this region.Discovery of the western salt sags and recognition of Donger salt sag which can be divided into two sub-salt sags in east and west are the new progress made in this study,indicating that the salt basin in northern Shaanxi is not a pan-shaped basin but contains several secondary salt sags controlled by relatively active syndepositonal faults.These secondary salt sags will be helpful to accumulation of potassium materials and provide enough accommodation space and structural positions for the large marine potash formation.更多还原