Fractal analysis of the ore-forming process in a skarn deposit: a case study in the Shizishan area, China

Abstract

This paper presents a tool for analysing the element distribution and mineralization intensity. The Hurst exponents and a-f(a) multifractal spectrum are utilized to analyse the irregular element distribution in Shizishan skarn orefield, China. The Hurst exponents reveal the Cu, Ag, Au and Zn distributions in the skarn-dominated drill cores are persistent and those in marble-dominated drill core are nearly random; the persistence indicates the mineralized segments are repeatedly developed, with accordance to multi-layer structure of the ore-controlling bedding faults and orebodies. The small amin (minimum multifractal singularity) of the Cu, Ag and Au in M1 reflect bare mineralization. The amin also displays that the mineralization intensities are varied for distinct elements and for different locations, yet the similarity of the distinct ore-forming processes is manifested by constant amin/f(amin) ratio. The constant ratio indicates the wider mineralization range denotes a more compact concentration distribution. The compact distributions represent the wide Cu, Ag and Au mineralization in skarns, and the loose distributions reflect the bare Cu, Ag and Au mineralization in marbles. Moreover amin shows a positive correlation with Hurst exponents in the Shizishan skarn orefield. Using fractal analysis the author's show that although the mineralization intensities for different elements and different locations along the Shizishan skarn orefield is not consistent, similar mineralization processes can be correlated to similar fractal exponents.

Fuzzification of continuous-value spatial evidence for mineral prospectivity mapping

“…To define threshold prospectivity values for classification of the prospectivity models, we used the concept of fractals (Mandelbrot, 1977(Mandelbrot, , 1983Mandelbrot et al, 1984). Several fractal methods have been developed and successfully applied to classify values in maps to be used as spatial evidence of mineral prospectivity, such as geochemical anomalies (e.g., Cheng, 1995Cheng, , 1999Cheng, , 2007Cheng and Agterberg, 2009;Cheng et al, 1994Cheng et al, , 1996Cheng et al, , 2010Carranza, 2008Carranza, , 2010bCarranza, , 2010cDeng et al, 2009Deng et al, , 2010Deng et al, , 2011Wang et al, 2011b;Zuo, 2011a,b,c;Zuo and Cheng, 2008;Zuo and Xia, 2009;Zuo et al, 2009b), structures like faults (e.g., Zhao et al, 2011), and geological features (e.g., Ford and Blenkinsop, 2008;Wang et al, 2011a;Zuo et al, 2009a). Here, we used the concentration-area model (C-A) (Figs.…”

Spatial pattern and dynamic control for mineralization in the Pulang porphyry copper deposit, Yunnan, SW China: Perspective from fractal analysis

“…The concentrations of metallogenic metals in mineralized zones often exhibit skewed statistical distributions and similarities in spatial distributions across a range of scales of several magnitudes of difference, and can be described by various fractal models (Deng et al, 2009Gumiel et al, 2010;He et al, 2013;Luz et al, 2014;Monecke et al, 2001;Wan et al, 2010;Wang et al, 2011aWang et al, , 2012aWang et al, , 2012b. The fractal models mostly belong to the self-similar domain, including the box-counting model (Mandelbrot, 1983;Rehman et al, 2013), number-size model (Turcotte, 2002;Wang et al, 2010aWang et al, , 2010b, concentration-area model (Cheng et al, 1994;Zuo et al, 2013), and perimeter-area model (Cheng, 1995), and partly belong to the self-affine domain (Wang et al, 2007) and multifractal domain (Agterberg et al, 1996;Arias et al, 2011;Cheng, 1999Cheng, , 2012Deng et al, 2008Deng et al, , 2011Wang et al, 2011b;.…”

The multifractal nature of the Ni geochemical field and implications for potential Ni mineral resources in the Huangshan–Jing'erquan area, Xinjiang, China

“…When q N 1, the higher values from μ i (ε) are more dominant in χ q (ε), and vice versa; when q = 1, all the values of μ i (ε) are equally important in χ q (ε), and they replicate the original measure (Wang et al, 2011).…”