Application of integrated geophysical method in prospecting: A case study of the magnetite-type IOCG deposits in the Moon Mountain exploration area, Copiapo, Chile
-
摘要: 智利科皮亚波地区地处海岸山带东侧的智利铁带北段，已发现多个中—大型磁铁矿型IOCG矿床，该类矿床的形成与大洋俯冲背景下陆缘弧中性—铁镁质火山岩和火山-沉积建造中早白垩世中酸性岩浆岩的侵入中心密切相关。该成矿带大面积被第四系砂砾层覆盖，在成矿地质特征研究基础上，采用综合地球物理方法对覆盖层下隐伏矿床（体）进行定位预测成为技术关键并具有现实需求。通过深入研究科皮亚波地区磁铁矿型IOCG矿床的成矿地质特征，并采用航磁深部地质解译初选勘查靶区，结合磁铁矿型IOCG矿床成矿地质-物性参数统计分析，建立了勘查区磁铁矿型IOCG矿床成矿地质-地球物理异常模式，采用综合地球物理方法在月亮山勘查区第四系覆盖区圈定的深部靶位经钻孔验证，发现了大型隐伏磁铁矿型IOCG矿床。Abstract: Many medium to large magnetite-type IOCG deposits have been found in the Copiapo area of Chile, which is located in the north fragment of the Chilean iron belt on the east side of the coastal mountain belt. The formation of these deposits is closely related to the neutral mafic volcanic rocks in the continental margin arc under the background of ocean subduction and the intrusion center of Early Cretaceous intermediate-acid magmatic rocks intruded in the volcanic sedimentary formation. The metallogenic belt is largely covered by Quaternary gravel layer. Using integrated geophysical methods with metallogenic geological characteristics to locate the concealed deposits (ore-bodies) under the overburden has become a key technology and a practical demand. We conducted an in-depth study of the metallogenic geological characteristics of magnetite-type IOCG deposits in the Copiabo area, and interpreted the preliminary exploration target by aeromagnetic deep-geological interpretation. Combining the interpretation results with the statistical analysis of metallogenic geological-physical parameters of magnetite-type IOCG deposits, a metallogenic geological-geophysical anomaly model of magnetite-type IOCG deposits in the Copiabo area is established. A large concealed magnetite-type IOCG deposit was found and verified by drilling in the deep target area delineated in the Quaternary coverage area of the Moon Mountain exploration area by using the integrated geophysical method.
-
图 1 智利中北部阿塔卡玛断裂带和IOCG矿床
Figure 1. Atacama fault zone and IOCG deposits in north central Chile
图 2 智利科皮亚波区域地质-航磁异常综合图(据Arévalo, 1995修改)
Figure 2. Integrated map of regional geology and aeromagnetic anomalies in Copiapo, Chile(modified after Arévalo, 1995)
图 3 智利科皮亚波地区航磁△T异常和系列上延异常图
a—△T异常; b—上延高度1000 m; c—上延高度2000 m; d—上延高度5000 m
Figure 3. Maps showing aeromagnetic anomaly and anomalies upward in Copiapo, Chile
(a) △T anomaly; (b) Upward continue to 1000 m; (c) Upward continue to 2000 m; (d) Upward continue to 5000 m
图 4 勘查区(月亮山7号点)及外围地质简图
Figure 4. Geological sketch of the exploration area (Spot 7 in the Moon Mountain area) and the periphery
图 5 勘查区(月亮山7号点)IOCG型铁铜矿区磁异常平面图
a—原始磁异常; b—剩余磁异常
Figure 5. Plan of magnetic anomaly of IOCG iron-copper deposits in the exploration area (Spot 7 in the Moon Mountain area)
(a) Original magnetic anomaly; (b) Remnant magnetic anomaly
图 6 反演三维磁化率模型图
图中灰度体为反演磁化率≥0.65SI的磁性体, 灰度由浅至深表示反演磁化率由0.65→0.90SI
Figure 6. Model of three-dimensional magnetic susceptibility inversion (coordinate unit: m)
The gray volumns are the magnetic volumns with inverse magnetic susceptibility ≥0.65SI, and the grayscale from light to dark indicates that the inverse magnetic susceptibility changes from 0.65 to 0.90SI
图 7 月亮山IOCG型铁铜矿区P2剖面综合断面图
Figure 7. Integrated section of Profile P2 of the IOCG iron-copper deposits in the Moon Mountain area
表 1 勘查区岩(矿)石磁化率参数测试统计表
Table 1. Statistical table of magnetic susceptibility parameters of rocks (ores) in the exploration area
岩矿石名称 标本数/块 SI/×10-3(国际单位制) ucgs(高斯单位制) 极值 平均值 极值 平均值 安山岩 34 9.47~25.50 14.81 754~2029 1179 安山质角砾岩 37 1.06~16.80 6.88 84~1337 547 构造角砾岩 33 0.13~8.27 3.70 10~658 294 硅化构造角砾岩 51 0.002~9.710 3.15 0~773 251 蚀变安山岩 31 0.22~6.84 2.62 18~544 241 闪长岩 162 14.70~68.50 39.10 1170~5451 3111 赤铁矿 65 0.14~21.70 6.95 11~1727 553 赤铁矿化硅化安山角砾岩 114 0.66~27.00 8.60 53~2149 688 磁铁矿化安山岩 28 24.80~124.00 55.30 1974~9868 4400 磁铁矿化硅化安山角砾岩 18 28.60~117.00 63.20 2276~9311 5032 磁赤铁矿 22 37.80~88.00 51.20 3008~7003 4074 磁铁矿 30 317~(>1000) 693.00 25226~(>80000) 55147 含铁铜安山质角砾岩 15 0.93~27.20 12.42 74~2165 988 含铜磁铁矿 9 77.10~526.00 195.80 6135~41858 15581 黄铁矿化硅化安山角砾岩 14 1.34~28.10 12.21 107~2236 971 表中">"表示大于 
下载: 导出CSV
表 2 勘查区岩(矿)石电阻率、极化率参数测试统计表
Table 2. Statistical table of resistivity and polarizability parameters of rocks (ores) in the exploration area
岩矿石名称 标本数/块 极化率/% 电阻率/(Ω·m) 最小 最大 平均值 最小 最大 平均值 赤铁矿 10 1.04 2.71 1.65 895.14 1835.30 1117.20 蚀变安山岩 6 0.69 1.89 1.20 147.09 813.03 529.80 安山岩 13 0.67 1.65 1.13 800.00 1350.96 1023.20 闪长岩 10 0.69 1.67 1.11 811.59 1822.71 1117.75 含铜磁铁矿 6 3.45 14.75 6.29 45.85 1430.97 330.58 磁铁矿 11 3.94 14.34 5.78 15.93 170.45 55.12 辉绿岩 2 0.76 1.00 0.88 160.84 485.56 323.20 构造角砾岩 13 0.45 2.11 1.19 853.03 1440.00 1116.29 黄铁矿化角砾岩 6 2.96 5.03 3.71 254.52 938.89 511.76
下载: 导出CSV
-
ARÉVALO C. 1995. MapaGeologico de La HojaCopiapo, III Región de Atacama[CM]. Servicio Nacional de Geología y Minería, Mapas Geológicos 8, escala 1: 100.000. BENAVIDES J, KYSER T K, CLARK A H, et al., 2007. The Mantoverde iron oxide-copper-gold district, III Región, Chile: the role of regionally derived, nonmagmatic fluids in chalcopyrite mineralization[J]. Economic Geology, 102(3): 415-440. doi: 10.2113/gsecongeo.102.3.415 BORICR, DÍAZ F, MAKSAEVV. 1990. Geología y Yacimientos Metalíferos de la Región de Antofagasta[Z]. Santiago, Chile: ServicioNacionalde Geologíay Minería, Boletín 40: 246. DALLMEYER R D, BROWN M, GROCOTT J, et al., 1996. Mesozoic magmatic and tectonic events within the Andean plate boundary zone, 26°-27°30'S, North Chile: constraints from 40Ar/39Ar mineral ages[J]. The Journal of Geology, 104(1): 19-40. doi: 10.1086/629799 ESPINOZA S, VIVALLO W, HENRIQUEZ F. 1994. Geologia y genesis de mineralizaciónmetalica en el distritoferrífero de Cerro Imán, Copiapó, Chile[J]. Congreso Geológico Chileno, 7: 799-802. FANG W X, LIU Y L, ZHANG S L, et al., 2009. Three types of continental geodynamics and metallogenic models for IOCG (Iron-oxide Copper Gold Deposits) from the global view[J]. Journal of Northwest University (Natural Science Edition), 39(3): 404-413. (in Chinese with English abstract) FANG W X, 2012. R & D on new mapping technology of geochemical Lithofacies in prediction and exploration for Iron-Oxide Copper Gold Deposits (IOCG)[J]. Advances in Earth Science, 27(10): 1178-1184. (in Chinese with English abstract) FANG W X, YANG X Y, GUO M H, et al., 2013. Relationships between alkaline Ti-Fe-Rich Gabbros and iron-oxide copper-gold deposits in the Baixila Ore District, Yunnan[J]. Geotectonicaet Metallogenia, 37(2): 242-261. (in Chinese with English abstract) FANG W X, LI J X, 2014. Metallogenic regulations, controlling factors, and evolutions of iron oxide copper and gold deposits in Chile[J]. Advances in Earth Science, 29(9): 1011-1024. (in Chinese with English abstract) FANG W X, DU Y L, LI J X, et al., 2018. Large scale structural petrography mapping technology and prospecting prediction[M]. Beijing: Geological Publishing House: 1-394. (in Chinese) FANG W X, 2019. Magmatic intrusive tectonic system I: tectonic Lithofacies mapping and ore-predication[J]. Geotectonicaet Metallogenia, 43(3): 473-506. (in Chinese with English abstract) FANG W X, WANG S C, JIA R X, et al., 2021. Theoretical innovation, technology research and development, and frontiers on large-scale mapping of tectonic lithofacies[J]. Mineral Exploration, 12(7): 1488-1518. (in Chinese with English abstract) GIMENEZ M, ACOSTA G, ALVAREZ O, et al., 2019. The subduction of the Copiapó aseismic ridge, is the causing of the formation of metallic minerals deposits in North of Chile and Argentina?[J]. Geodesy and Geodynamics, 10(6): 471-476. doi: 10.1016/j.geog.2019.04.007 HERVÉ F, GODOY E, PARADA M A, et al., 1987. A general view on the Chilean-argentine Andes, with emphasis on their early history[M]//MONGER J W H, FRANCHETEAU J. Circum-Pacific Orogenic belts and evolution of the Pacific Ocean Basin. Washington: American Geophysical Union: 97-114. HITZMAN M W, 2000. Iron oxide-Cu-Au deposits: what, where, whenand why[M]//PORTERT M. Hydrothermal iron oxide copper-gold and related deposits: a global perspective. Adelaide: PGC Publishing: 9-25. LARA Land GODOY E. 1998. Mapa Geologico de La Hoja Quebrada Salitrosa, III Región de Atacama[R]. Santiago, Chile: Servicio Nacional de Geología y Minería, MapasGeológicos 4, escala 1: 100.000. LI J W, ZHU G R, ZHANG D Q, et al., 2009. Discovery of Dongjun lead-zinc-silver deposit in Inner Mongolia: an integrated application of geological, geochemical and geophysical prospecting methods[J]. Mineral Deposits, 28(6): 830-837. (in Chinese with English abstract) LI J X, FANG W X, LIU J J, 2011. Types and characteristics of regional tectonics and ore-field structures of iron oxide-copper-gold deposits in Chile[J]. Geology and Exploration, 47(2): 323-332. (in Chinese with English abstract) LI T C, YANG X Y, PENG X M, et al., 2015. Geological characteristics and prospecting criteria of the magnetite deposits in Cerro Iman-Cerro Lunar-Cerro Norte area, central-northern Chile[J]. Mineral Exploration, 6(1): 77-85. (in Chinese with English abstract) LIU R, MA J Q, LI Q C, et al., 2016. Gravity, magnetic and electric comprehensive geophysical prospecting for deep structures in HetaoBasin[J]. Journal of Geomechanics, 22(4): 943-954. (in Chinese with English abstract) LV Q T, MENG G X, YAN J Y, et al., 2019. Multi-scale exploration of mineral system: concept and progress: a case study in the middle and lower reaches of the Yangtze River MetallogenicBelt[J]. Geology in China, 46(4): 673-689. (in Chinese with English abstract) MAO J W, YU J J, YUAN S D, et al., 2008. Iron oxide-copper-gold deposits: characteristics, present research situation and ore prospecting[J]. Mineral Deposits, 27(3): 267-278. (in Chinese with English abstract) MARSCHIK R, FONTBOTÉ L, 1996. Copper(-iron) mineralization and superposition of alteration events in the Punta del Cobre belt, northern Chile[M]//CAMUS E, SILLITOE R H, PETERSON R. Andean copper deposits: new discoveries, mineralisation, styles and metallogeny. Littleton, USA: Society of Economic Geologists, Special Publication 5: 171-189. MARSCHIK R, FONTBOTÉ L, 2001. The Candelaria-Punta del Cobre iron oxide Cu-Au (-Zn-Ag) deposits, Chile[J]. Economic Geology, 96(8): 1799-1826. MATHUR R, MARSCHIK R, RUIZ J, et al., 2002. Age of mineralization of the CandelariaFe oxide Cu-Au deposit and the origin of the Chilean iron belt, based on Re-Osisotopes[J]. Economic Geology, 97(1): 59-71. doi: 10.2113/gsecongeo.97.1.59 MCCAFFERTY A E, PHILLIPS J D, HOFSTRA A H, et al., 2019. Crustal architecture beneath the southern Midcontinent (USA) and controls on Mesoproterozoic iron-oxide mineralization from 3D geophysical models[J]. Ore Geology Reviews, 111: 102966. doi: 10.1016/j.oregeorev.2019.102966 MPODOZIS C, RAMOS V, 1990. The Andes of Chile and Argentina: circum-Pacific council for energy and mineral resources[J]. Earth Science Series, 11: 59-90. OYARZUN R, OYARZÚN J, MÉNARD J J, et al., 2003. The Cretaceous iron belt of northern Chile: role of oceanic plates, a superplume event, and a major shear zone[J]. Mineralium Deposita, 38(5): 640-646. doi: 10.1007/s00126-003-0359-y RAMÍREZ L E, PALACIOS C, TOWNLEY B, et al., 2006. The MantosBlancos copper deposit: an upper Jurassic breccia-style hydrothermal system in the coastal range of northern Chile[J]. Mineralium Deposita, 41(3): 246-258. doi: 10.1007/s00126-006-0055-9 RYAN P J, LAWRENCE A L, JENKINS, R A, et al., 1995. The Candelaria copper-gold deposit, Chile[J]. Arizona Geological Society Digest, 20: 625-645. http://www.researchgate.net/publication/284671519_The_Candelaria_copper-gold_deposit_Chile SHEN P, SHEN Y C, LIU T B, 2011. Geophysical-geological prospecting models for positioning prognosis of hidden metal deposits[J]. Earth Science Frontiers, 18(3): 284-292. (in Chinese with English abstract) http://search.cnki.net/down/default.aspx?filename=DXQY201103029&dbcode=CJFD&year=2011&dflag=pdfdown SILLITOE R H, 2003. Iron oxide-copper-gold deposits: an Andean view[J]. Mineralium Deposita, 38(7): 787-812. doi: 10.1007/s00126-003-0379-7 SILLITOE R H, PERELLÓ J, 2005. Andean copper province: tectonomagmatic settings, deposit types, metallogeny, exploration, and discovery[M]//HEDENQUIST J W, THOMPSON J F H, GOLDFARB R J, et al. Economic geology one hundredthanniversary volume 1905-2005. Littleton, Colorado: Society of Economic Geologists: 845-890. SKIRROW R G, MURR J, SCHOFIELD A, et al., 2019. Mapping iron oxide Cu-Au (IOCG) mineral potential in Australia using aknowledge-driven mineral systems-based approach[J]. Ore Geology Reviews, 113: 103011. doi: 10.1016/j.oregeorev.2019.103011 STEIGER R H, JÄGER E, 1977. Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology[J]. Earth and Planetary Science Letters, 36(3): 359-362. UYEDA S, KANAMORI H, 1979. Back-arc opening and the mode of subduction[J]. Journal of Geophysical Research, 84(B3): 1049-1061. doi: 10.1016/0012-821X(77)90060-7 VILA T. 1996. Geology of the MantoVerde copper deposit, northern Chile: a specularite-rich, hydrothermal-tectonic breccia related to the Atacama fault zone[M]//CAMUS F, SILLITOE R M, PETERSEN R. Andean copper deposits: new discoveries, mineralization, styles and metallogeny. Littleton, USA: Society of Economic Geologists, Special Publication 5: 157-170. VIVALLO W, ESPINOZA S, HENRÍQUEZ F. 1995. Metasomatismo y alteraciónhidrotermal en el Distrito Ferrífero Cerro Negro Norte, Copiapó, Chile[J]. RevistaGeológica de Chile, 22: 75-88. ZHAI Y S, 2007. Earth system, metallogenic system to exploration system[J]. Earth Science Frontiers, 14(1): 172-181. (in Chinese with English abstract) http://en.cnki.com.cn/Article_en/CJFDTOTAL-DXQY200701017.htm ZHANG X C, 2003. The characteristics of the overseas iron-oxide Cu-Au deposits and the present situation of the studies[J]. Advance in Earth Sciences, 18(4): 551-560. (in Chinese with English abstract) 方维萱, 柳玉龙, 张守林, 等, 2009. 全球铁氧化物铜金型(IOCG)矿床的3类大陆动力学背景与成矿模式[J]. 西北大学学报(自然科学版), 39(3): 404-413. https://www.cnki.com.cn/Article/CJFDTOTAL-XBDZ200903010.htm 方维萱, 2012. 论铁氧化物铜金型(IOCG)矿床地球化学岩相学填图新技术研发[J]. 地球科学进展, 27(10): 1178-1184. https://www.cnki.com.cn/Article/CJFDTOTAL-DXJZ201210021.htm 方维萱, 杨新雨, 郭茂华, 等, 2013. 云南白锡腊碱性钛铁质辉长岩类与铁氧化物铜金型矿床关系研究[J]. 大地构造与成矿学, 37(2): 242-261. doi: 10.3969/j.issn.1001-1552.2013.02.008 方维萱, 李建旭, 2014. 智利铁氧化物铜金型矿床成矿规律、控制因素与成矿演化[J]. 地球科学进展, 29(9): 1011-1024. https://www.cnki.com.cn/Article/CJFDTOTAL-DXJZ201409005.htm 方维萱, 杜玉龙, 李建旭, 等, 2018. 大比例尺构造岩相学填图技术与找矿预测[M]. 北京: 地质出版社: 1-394. 方维萱, 2019. 岩浆侵入构造系统Ⅰ: 构造岩相学填图技术研发与找矿预测效果[J]. 大地构造与成矿学, 43(3): 473-506. https://www.cnki.com.cn/Article/CJFDTOTAL-DGYK201903008.htm 方维萱, 王寿成, 贾润幸, 等, 2021. 大比例尺构造岩相学填图理论创新、技术研发与发展方向[J]. 矿产勘查, 12(7): 1488-1518. doi: 10.3969/j.issn.1674-7801.2021.07.003 李建旭, 方维萱, 刘家军, 2011. 智利铁氧化物-铜-金矿床区域定位构造-矿田构造类型与特征[J]. 地质与勘探, 47(2): 323-332. https://www.cnki.com.cn/Article/CJFDTOTAL-DZKT201102026.htm 李进文, 朱广仁, 张德全, 等, 2009. 内蒙古东珺铅锌银矿床的发现: 地物化综合找矿勘查方法的运用[J]. 矿床地质, 28(6): 830-837. doi: 10.3969/j.issn.0258-7106.2009.06.011 李天成, 杨新雨, 彭晓明, 等, 2015. 智利中北部赛罗伊曼-月亮山-赛罗诺尔戴磁铁矿矿床地质特征与找矿标志[J]. 矿产勘查, 6(1): 77-85. doi: 10.3969/j.issn.1674-7801.2015.01.010 刘嵘, 马见青, 李庆春, 等, 2016. 重磁电综合地球物理探测河套盆地深部结构[J]. 地质力学学报, 22(4): 943-954. doi: 10.3969/j.issn.1006-6616.2016.04.012 吕庆田, 孟贵祥, 严加永, 等, 2019. 成矿系统的多尺度探测: 概念与进展: 以长江中下游成矿带为例[J]. 中国地质, 46(4): 673-689. https://www.cnki.com.cn/Article/CJFDTOTAL-DIZI201904002.htm 毛景文, 余金杰, 袁顺达, 等, 2008. 铁氧化物-铜-金(IOCG)型矿床: 基本特征、研究现状与找矿勘查[J]. 矿床地质, 27(3): 267-278. doi: 10.3969/j.issn.0258-7106.2008.03.001 申萍, 沈远超, 刘铁兵, 2011. 隐伏矿体定位预测的地球物理-地质找矿模型: 以地质与EH4双源大地电磁测深技术结合为例[J]. 地学前缘, 18(3): 284-292. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201103029.htm 翟裕生, 2007. 地球系统、成矿系统到勘查系统[J]. 地学前缘, 14(1): 172-181. doi: 10.3321/j.issn:1005-2321.2007.01.017 张兴春, 2003. 国外铁氧化物铜-金矿床的特征及其研究现状[J]. 地球科学进展, 18(4): 551-560. doi: 10.3321/j.issn:1001-8166.2003.04.011 -
下载:
图(7) / 表(2)
计量
- 文章访问数: 651
- HTML全文浏览量: 271
- PDF下载量: 88
- 被引次数: 0
