摘要
地球物理勘探在众多岩浆铜镍硫化物矿床的发现中起着重要的作用.相对于围岩,硫化物矿石在电学、密度和磁化率等物理性质方面有着显著的差异性,产生高重力、高磁力、高极化和低电阻的地球物理异常,是岩浆铜镍硫化物矿床传统地球物理勘探方法的理论基础.造山带中铜镍硫化物矿床通常具有小岩体成大矿的特征,以中亚造山带的东天山和喀拉通克地区最为突出.这类矿床通常表现出复杂的岩体形态、产状、岩相构成、赋矿岩相和矿体空间展布,给传统地球物理勘查工作提出挑战.国外铜镍矿最大探测深度已达到4000m,最大开采深度也达到2450m,而我国同类矿床分别只有1600m和900m左右,亟待提高.以高分辨率浅层地震波反射、地-井瞬变电磁法、井中重力勘探和航空电磁法为代表的地球物理新进展则为这一问题带来新思路,可能代表着铜镍硫化物矿床大深度精细勘探的发展趋势.
Geophysical explorations have played an important role in the discovery of many magmatic Cu-Ni sulfide deposits.Comparing to the surrounding country rocks,sulfide ores posses strong anomaly in many physical properties including electrical property,density and magnetic susceptibility,leading to the geophysical anomalies of higher magnetic force,higher gravity,higher polarizability and lower resistivity,which is the theoretical basis of the traditional geophysical methods for magmatic Cu-Ni sulfide deposits.In Central Asian Orogenic Belt（CAOB）,the deposits mostly show the characteristic that large Cu-Ni deposits occurred in small intrusions,especially in Eastern Tianshan Ni-Cu belt and Kalatongke ore district.These Ni-Cu deposits occurred in CAOB are so much complicated in intrusion size,occurrence,lithofacies,orebearing lithology and space distribution of orebodies,making the traditional geophysical exploration in the orogenic belts is more difficult.The maximum exploitation depth of foreign NiCu deposits has reached more than 4000 meters,and the largest mining depth is 2450 meters.Whereas,the similar type of deposits are only 1600 meters and 900 meters respectively,which needs to be improved. Recent development in geophysical technology,including high-resolution shallow-level seismic reflection,borehole transient electromagnetic method,borehole gravity and airborne electromagnetic,throw light on these problems,and may represent the development tendency of fine exploration for Cu-Ni deposit in the near future.
出处
《地球物理学进展》
CSCD
北大核心
2014年第6期2800-2817,共18页
Progress in Geophysics
基金
国家自然科学基金重点项目(41030424)
新疆有色集团东天山、喀拉通克铜镍硫化物矿床预测评价研究项目联合资助
