A processing technique of step effect in concentration-area multifractal method
HAN Deng-Hui1(), GAO Shun-Bao2(), ZHENG You-Ye1,2, CHEN Xin1, JIANG Xiao-Jia1, GU Yan-Rong1, YAN Chen-Chen1
1. Faculty of Earth Resource, China University of Geosciences(Wuhan), Wuhan 430074, China 2. Geological Survey, China University of Geosciences(Wuhan), Wuhan 430074, China
In the geochemical stream sediment survey, obvious differences in geochemical backgrounds of different geological bodies will affect the anomaly delineation and even lead to enhancement of anomalies irrelevant to mineralization, which weakens the mineralization-related weak anomalies. In this paper,the influence of step effect data on the fractal distribution form is discussed from the mathematical view based on the superposition law of fractal distribution, and an improved method for eliminating step effects in concentration-area fractal theory is proposed.In this method, the authors divide the study area based on geochemical background and then discuss fractal distribution forms respectively.The result shows that this method can accurately filter irrelevant lithology information and identify weak anomalies caused by mineralization in low-background sub-zone. It is applicable to the extraction of geochemical mineralization-related anomaly in the areas seriously affected by lithology.
Deng-Hui HAN,Shun-Bao GAO,You-Ye ZHENG, et al. A processing technique of step effect in concentration-area multifractal method[J]. Geophysical and Geochemical Exploration,
2020, 44(6): 1420-1428.
Tectonics and position regional map of Gangdise(a)[27], sketch map of regional mineral resources(b) and geological map(c) in Pujie area 1—upper Carboniferous-lower Permian Laga formation(C2P1l); 2—lower Permian Angjie formation(P1a); 3—Paleocene Dianzhong formation(E1d); 4—Eocene Nianbo formation(E2n); 5—upper Cretaceous Jiangba formation(K2jb); 6—intrusions; 7—Quaternary sediments(Q); 8—Duijiala reverse fault
参数
Au
Ag
Cu
Pb
Zn
Cd
W
Sn
Mo
Bi
As
Sb
Hg
P
Mn
B
平均值
0.85
0.10
13.57
55.21
77.90
0.19
3.45
5.79
0.89
0.60
36.77
1.91
0.03
400.26
628.07
54.30
标准差
2.63
0.77
14.17
148.16
84.91
0.38
5.44
16.75
1.17
1.49
367.71
3.59
0.01
229.32
478.59
30.56
富集系数
0.99
1.73
0.8
2.91
1.15
2.34
3.56
2.76
1.44
3.33
8.36
5.63
0.55
0.73
1.08
2.59
变异系数
3.11
7.45
1.04
2.68
1.09
2.02
1.58
2.89
1.31
2.49
10
1.88
0.42
0.57
0.76
0.56
地层
衬值
Au
Ag
Cu
Pb
Zn
Cd
W
Sn
Mo
Bi
As
Sb
Hg
P
Mn
B
第四系
1.32
1.33
1.27
1.15
1.16
1.17
1.02
1.55
0.98
1.12
1.52
1.18
1.03
1.19
1.11
1.07
昂杰组
1.6
1.17
1.72
1.04
1.29
1.17
1.03
1
1.06
1.24
1.24
1.24
1.2
1.52
1.23
1.61
晚白垩—始新世岩体
0.92
1.17
0.91
0.86
1.03
1
1.01
0.83
1.06
0.74
1.05
0.75
0.94
1.47
1.05
0.94
年波组
1.48
1.83
0.62
2.07
1.15
2.17
1.35
2.35
0.98
1.68
4.04
1.66
0.72
0.6
1.11
0.72
拉嘎组
2.02
1.25
1.83
1.07
1.36
1.28
1.09
1
0.99
1.16
1.27
1.11
1.29
1.52
1.14
1.38
典中组
0.9
2.17
0.63
1.66
1.07
1.5
1
1.1
1.28
0.96
0.92
1.13
0.91
0.75
1.02
0.77
Statistic characteristic geochemistry exploration data from Pujie area
Geochemistry contour map and background division from Pujie area a—geochemical contour map of Cu; b—geochemical contour map of Zn; c—geochemical contour map of Au; d—geochemical background division from Pujie area; 1—subzone of Carboniferous-Permian sedimentary strata;2—subzone of Paleogene volcanic strata
Concentration-area double logarithmic plot and section lines fitting patterns of Ag(a),Pb(b),Zn(c),Au(d),Sn(e),W(f) in whole-area from Pujie area
Concentration-area double logarithmic plot and section lines fitting patterns of Ag(a),Pb(b),Zn(c),Au(d),Sn(e),W(f) in subzone-1 from Pujie area
Concentration-area double logarithmic plot and section lines fitting patterns of Ag(a),Pb(b),Zn(c),Au(d),Sn(e),W(f) in subzone-2 from Pujie area
元素
全区
分区
元素
全区
分区
1区
2区
1区
2区
C编号
数值
C编号
数值
C编号
数值
C编号
数值
C编号
数值
C编号
数值
C1
0.069
C1
47.809
C1
0.369
C1
78.946
C1
76.254
C2
0.482
〗
C2
79.604
Ag
C2
1.599
Zn
C2
110.59
C2
109.262
C1
0.725
C3
241.29
C2
1.608
C3
363.735
C3
349.865
C3
19.204
C3
17.948
C4
780.408
C1
107.037
C1
109.4
C1
6.6796
C1
8.324
Pb
C2
409.117
C1
437.8
W
C1
6.475
C3
1036.91
C2
858.428
C2
13.377
C1
5.56
C1
2.926
C1
2.329
C1
2.072
C2
10.253
C2
4.808
Sn
C1
18.236
C1
12.306
Au
C2
26.379
C3
16.652
C2
66.535
C3
71.253
C2
180.047
C2
182.435
Inflect points of fitting straight line in concentration-area double logarithmic plot from two subzones and whole-area of Pujie area
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