【摘要】 高分辨率反射地震在探测深度和分辨率方面具有其它方法无法比拟的优势,为试验该方法在探测深部似"层状"矿床和控矿构造方面的探测效果,作者于2008年在安徽庐枞(庐江-枞阳)矿集区的罗河-泥河-大包庄矿区采集了2条10km的高分辨率反射地震剖面。尽管矿区构造较为复杂,但偏移剖面仍发现了很多与地质吻合的反射。白垩纪沉积盆地(红盆)呈现清晰的三层结构,反映该地区白垩纪以来在伸展构造背景之下沉积环境还存在阶段性变化;盆地之下的反射更可能为晚侏罗世的碎屑岩沉积或中三叠世的碳酸盐岩沉积,红盆之下可能不存在庐枞"耳状"火山岩盆地的另一半。火山岩层大致也呈现3层结构,火山沉积岩层(双庙、砖桥组)的厚度在800～1000m,火山沉积岩之下有明显的"穹隆"状反射,可能为与侵入体有关的隆起。对照精细建立的矿床地质剖面,发现罗河、泥河矿体能够产生清晰的反射,初步证实高分辨反射地震可以直接探测到矿体,但当矿体陡倾、或结构形态复杂、或空间尺寸较小时,对应矿体位置没有可辨识的反射。试验结果表明高分辨率反射地震可以用于探测深部控矿构造,在合适条件下,可以探测似"层状"矿体。更多还原

【Abstract】 High resolution seismic reflection method has the incomparable advantages over other methods in detecting depth and resolution.In order to test the effectiveness of this method in detecting deep stratiform-like deposit and ore-controlling structure,the author had collected two 10km long high-resolution reflection seismic profiles in Luohe-Nihe-Dabaozhuang mining area of Lu-Zong(Lujiang-Zongyang)ore district in Anhui Province in 2008.Although the structure of mining area is more complex,the migrated section has still showed many reflections which tallies with the geology.Cretaceous sedimentary basin(Cretaceous red basin)is showed a clear three-layer structure which indicate the stage changes in depositional environment under the extensional tectonics since Cretaceous.The reflections beneath the basin are more likely due to the clastic sediments of Late Jurassic,or the Carbonate sediments of Middle Triassic,and there may not exist the other half of the Lu-Zong volcanic terrane under the red basin.The volcanic strata also approximately presents three-layer structures,the thickness of the volcanic sedimentary strata(ShuangMiao Formation,ZhuanQiao Formation)is 800 to 1000 meters,there is obvious a "dome-shaped"reflection under the volcanic sedimentary rock,it is may be an intrusive related uplift.Compared with the finely builted deposit geological section,we can discover that Luohe and Nihe ore body have showed clear reflections,that initially confirmed the high resolution seismic reflection method can be directly used to detect the ore body,but when the ore body is steep and sloping,complex configuration and smaller size,it can not produce recognizable reflection.The test results show that high resolution seismic reflection method can be used to detect deep ore-controlling structure,even stratiform-like deposit in suitable conditions.更多还原