Singular-Value Decomposition (SVD) for Extraction of Gravity Anomaly Associated with Gold Mineralization in the Tongshi Gold Orefield, Western Shandong Province, East China
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摘要: 基于MATLAB平台编制的奇异值分解(SVD)程序有效地应用于铜石金矿田1∶50 000重力数据分解.首先，利用奇异值分解将重力数据分解为一系列的特征值空间；然后运用多重分形技术确立反映不同层次控矿因素的特征空间值的临界值，最后将这些具有不同控矿因素特征的特征空间值按一定的规则进行数据重构.结果获取三幅刻画不同尺度控矿因素的重力异常图像.(1)区域控矿地质因素是位于平邑火山沉积盆地(重力异常值-56~-974 μm/s2)南西侧NW向基底隆起(重力异常值-55~567 μm/s2)的鞍谷部位(重力异常值-55~51 μm/s2)，这里为构造上的局部拉张区，控制铜石杂岩体以及所有金矿床的整体分布，是金成矿的有利地段.(2)局部控矿因素是具有重力负异常特征(重力异常值-339~-11 μm/s2)的铜石杂岩体和围绕杂岩体形成的具有环形重力正异常(重力异常值37~345 μm/s2)接触交代带，斑岩型金矿化位于岩体内部，矽卡岩型金矿化形成于接触带中，而隐爆角砾岩型和卡林型金矿化形成于接触交代带外围；因此，岩体及其环形接触交代带是金矿成矿的潜在地段.(3)具体控矿因素是NE和NW向重力异常反应的两个方向断裂交汇域，几乎所有金矿化都位于这些交汇域，因此，这里是金成矿的远景地段.(4)铜石金矿田具有典型的多重因素控矿的复杂性特征.Abstract: A singular-value decomposition (SVD) program on a MATLAB platform was effectively used to handle gravity signals for the Tongshi gold field. Firstly. The gravity signals are firstly decomposed into different eigenimages with singular-value decomposition method. Secondly, the thresholds between the eigenvalues reflecting different layers of ore-controlling factors are established by multi-fractal method. Finally the eigenvalues with different layers of ore-controlling factors were rebuilt on certain mathematical rules. This yielded three layers of two-dimensional singular-value images that meticulously depict ore-controlling factors in different scales respectively. (1) The regional ore-controlling factor is a saddle valley with the gravity anomaly values varying from -55 to 51 μm/s2 of the NW trending swell with the gravity anomaly values varying from -55 to 567 μm/s2 on the SW side of the Mesozoic volcanic sedimentary basin with the gravity anomaly values varying from -56 to -974 μm/s2. The saddle valley might be tectonically an extensional area where the Tongshi complex pluton and all gold deposits are located and thus this area is a favorable area for gold deposits. (2) The local ore-controlling factor is the Tongshi complex pluton with a negative circular gravity anomaly varying from -339 to -11 μm/s2 and the ring contact metasomatic mineralization zone around the Tongshi complex with the positive gravity anomaly varying from 37 to 345 μm/s2. The porphyry gold occurrences are located within the Tongshi intrusive complex and Skarn iron-copper-gold occurrences are located in the inner contact metasomatic zone between the intrusive complex and its host rocks. Crypto-breccia and Carlin-type gold deposits are located at the outer contact metasomatic zone between the intrusive complex and its host rocks. Thus the two areas are potential areas for gold deposits. (3) The concrete ore-controlling factor is crossing areas between the NE trending faults and NW trending faults reflected by the two trending gravity anomaly zones. Almost all gold deposits are located within crossing areas and thus these areas are prospective areas for gold deposits. (4) The Tongshi gold field has a typical complexity with multi-layers of ore-controlling factors.
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图 1 铜石金矿田地质矿产分布(据Chen and Liu, 2000修编)
1.第四纪沉积物；2.白垩纪火山沉积岩；3.侏罗纪火山沉积岩；4.奥陶纪碳酸盐岩；5.寒武纪碳酸盐岩；6.太古代泰山群；7.燕山期闪长玢岩；8.燕山期正长斑岩；9.隐爆角砾岩；10.斑岩型金矿点；11.矽卡岩型金矿点；12.隐爆角砾岩型金矿床；13.卡林型金矿床；14.断裂；15.地质界线；16.不整合地质界线
Fig. 1. Geological map of the Tongshi gold field
图 2 铜石金矿田1∶50 000原始重力数据图像(金矿点图例见图 1)
Fig. 2. The original gravity data image surveyed at scale 1∶50 000
图 3 lnλ-lnE(λ|λ＞λi)对数图
使用最小二乘法拟合3条具有不同斜率的线段，分割点p=3，q=9，lnλ3=17.13，lnλ9=14.17
Fig. 3. ln-ln plot of λ-E with two break points
图 4 第1、2特征空间对应的重力图像(金矿床类型见图 1)
Fig. 4. Image corresponding to the 1st and 2nd eigenimages
图 5 第3至第8特征空间所对应的重力图像(金矿床类型图例同图 1)
Fig. 5. Reconstructed image from the 3rd to 8th eigenimages
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Cagnoli, B., Ulrych, T.J., 2001. Singular value decomposition and wavy reflections in ground-penetrating radar images of base surge deposits. Journal of Applied Geophysics, 48(3): 175-182. doi: 10.1016/S0926-9851(01)00089-1 Chen, Y.Q., Liu, H.G., 2000. Delineation of potential mineral resources region based on geo-anomaly unit. Journal of China University of Geosciences, 11(2): 158-163. http://www.cqvip.com/QK/84134A/20002/4000690583.html Chen, Y.Q., Zhao, P.D., Chen, J.G., et al., 2001. Application of the geo-anomaly unit concept in quantitative delineation and assessment of gold ore targets in western Shangdong uplift terrain, eastern China. Natural Resources Research, 10(1): 35-49. doi: 10.1023/A:1011581414877 Chen, Y.Q., Zhao, P.D., Liu, H.G., 2001. Accumulation and evolution of ore-forming composition of gold deposits in the western Shandong uplift terrain. Earth Science—Journal of China University of Geosciences, 26(1): 41-48 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQKX200101008.htm Cheng, Q.M., 2007. Mapping singularities with stream sediment geochemical data for prediction of undiscovered mineral deposits in Gejiu, Yunnan Province, China. Ore Geology Reviews, 32(1-2): 314-324. doi: 10.1016/j.oregeorev.2006.10.002 Cheng, Q.M., 2008. Non-linear theory and power-law models for information integration and mineral resources quantitative assessments. Math. Geosci. , 40(5): 503-532. doi: 10.1007/s11004-008-9172-6 Cheng, Q.M., Zhao, P.D., Chen, J.G., et al., 2009a. Application of singularity theory in prediction of tin and copper mineral deposits in Gejiu district, Yunnan, China: weak information extraction and mixing information decomposition. Earth Science—Journal of China University of Geosciences, 34(2): 232-242 (in Chinese with English abstract). doi: 10.3799/dqkx.2009.021 Cheng, Q.M., Zhao, P.D., Zhang, S.Y., et al., 2009b. Application of singularity theory in prediction of tin and copper mineral deposits in Gejiu district, Yunnan, China: information integration and delineation of mineral exploration targets. Earth Science—Journal of China University of Geosciences, 34(2): 243-252 (in Chinese with English abstract). doi: 10.3799/dqkx.2009.022 Freire, S.L.M., Ulrych, T.J., 1988. Application of singular value decomposition to vertical seismic profiling. Geophysics, 53(6): 778-785. doi: 10.1190/1.1442513 Glifford, G.D., 2005. Singular value decomposition & independent component analysis for blind source separation. HST582J/6.555J/16.456J, Biomedical signal and Image Processing, Spring 2005. Hu, H.B., Mao, J.W., Niu, S.Y., et al. 2005. Study on ore-forming fluids of the Guilaizhuang gold deposits in Pingyi, western Shangdong. J. Mineral. Petrol. , 25(1): 38-44 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-KWYS200501008.htm Li, Q.M., 2005. GIS-based multifractal/inversion methods for feature extraction and applications in anomaly identification for mineral exploration(Ph. D. thesis). York University, Toronto, Canada. 211. Li, Q.M., Cheng, Q.M., 2004. Fractal singular value (Eginvalue) decomposition method for geophysical and geochemical anomaly reconstruction. Earth Science—Journal of China University of Geosciences, 29 (1): 109-118 (in Chinese with English abstract). http://d.wanfangdata.com.cn/Periodical/dqkx200401019 Li, Q.M., Liu, S.H., 2003. Geophysical signal decomposition by singular method and application in GIS. Process in Geophysics, 18(1): 97-102 (in Chinese with English abstrace). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DQWJ200301016.htm Lin, J.Q., Tan, D.J., Jin, Y., 1996. 40Ar/39Ar ages of Mesozoic igneous activities in western Shandong. Acta Petrologica et Mineralogica, 15(3): 213-220 (in Chinese with English abstract). http://www.researchgate.net/publication/284321888_40Ar39Ar_ages_of_Mesozoic_igneous_activities_in_western_Shandong Vrabie, V.D., Mars, J.I., Lacoume, J.L., 2004. Modified singular value decomposition by means of independent component analysis. Signal Processing, 84(3): 645-652. doi: 10.1016/j.sigpro.2003.12.007 Wang, S.C., Liu, Y.Q., Yi, P.H., et al., 2003. Gold deposits and the synthetic information metallogenic prognosis in gold deposit concentrated area. Geological Publishing House, Beijing (in Chinese). Yu, X.F., 2001. Ore-forming series and model of Tongshi gold field in Pingyi, Shangdong Province. Shangdong Geology, 17(3-4): 59-64 (in Chinese with English abstract). http://www.researchgate.net/publication/286785713_Ore-forming_series_and_model_of_tongshi_gold_field_in_pingyi Zhu, D.P., Zhang, X.M., Li, S.Q., et al., 2000. The mineralization types of Tongshi district of secondary volcanic complex rock mass in Pingyi County and their geological feature of mineralization. Gold, 21(8): 8-11 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-HJZZ200008002.htm 陈永清, 赵鹏大, 刘红光, 2001. 鲁西金矿成矿组分的聚集与演化. 地球科学——中国地质大学学报, 26(1): 41-48. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200101008.htm 成秋明, 赵鹏大, 陈建国, 等, 2009a. 奇异性理论在个旧锡铜矿产资源预测中的应用: 成矿弱信息提取和复合信息分解. 地球科学——中国地质大学学报, 34(2): 232-242. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200902001.htm 成秋明, 赵鹏大, 张生元, 等, 2009b. 奇异性理论在个旧锡铜矿产资源预测中的应用: 综合信息集成与靶区圈定. 地球科学——中国地质大学学报, 34(2): 243-252. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200902002.htm 胡华斌, 毛景文, 牛树银, 等, 2005. 鲁西平邑归来庄金矿床成矿流体研究. 矿物岩石, 25(1): 38-44. doi: 10.3969/j.issn.1001-6872.2005.01.008 李庆谋, 成秋明, 2004. 分形奇异(特征)值分解方法与地球物理和地球化学异常重建. 地球科学——中国地质大学学报, 29(1): 109-118. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX200401019.htm 李庆谋, 刘少华, 2003. GIS环境下地球物理信号的奇异值分解、多维分形特征与应用. 地球物理学进展, 18(1): 97-102. doi: 10.3969/j.issn.1004-2903.2003.01.016 林景仟, 谭东娟, 金烨, 1996. 鲁西地区中生代火成活动的40Ar/39Ar年龄. 岩石矿物学杂志, 15(3): 213-220. https://www.cnki.com.cn/Article/CJFDTOTAL-YSKW603.002.htm 王世称, 刘玉强, 伊丕厚, 等, 2003. 山东省金矿床及金矿床密集区综合信息成矿预测. 北京: 地质出版社. 于学峰, 2001. 山东平邑铜石金矿田成矿系列及成矿模式. 山东地质, 17(3-4): 59-64. https://www.cnki.com.cn/Article/CJFDTOTAL-SDDI2001Z1010.htm 祝德平, 张晓梅, 李守全, 等, 2000. 平邑县铜石次火山杂岩体区金矿化类型及其成矿地质特征. 黄金, 21(8): 8-11. https://www.cnki.com.cn/Article/CJFDTOTAL-HJZZ200008002.htm -
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