Geoscience Reference
In-Depth Information
r (x)
3
2.5
2
1.5
1
0.5
x
20
40
60
80
100
120
Fig. 12.33 Blue: original Pulacayo zinc values, with x representing horizontal distance in units of
2 m. Pink: universal multifractal simulation results for Levy index ʱ ¼ 1.8; co-dimension
C 1 ¼ 0.03 characterizing the “sparseness” of the mean field; and deviation from conservation
H ¼0.090. Both patterns were normalized to unity (mean ¼15.6 % Zn) (Source: Lovejoy and
Schertzer 2007 , Fig. 3a)
characterizes the deviation from conservation. A space-time universal multifractal
field for element concentration can be subject to change of its mean value in the
course of time. Even in static 3-D situations, incorporation of H into the model
provides increased flexibility. Lovejoy and Schertzer ( 2007 ) provide examples of
geophysical data for which the universal multifractal approach is applicable. This
includes applications to magnetic susceptibility data studied by Pilkington and
Todoeschuck ( 1995 ).
12.7.1 Pulacayo Mine Example
Figure 12.33 taken from Lovejoy and Schertzer ( 2007 ) shows a realistic universal
multifractal simulation for the Pulacayo orebody using the following three param-
eters: L´vy index
α ¼
1.8, codimension C 1 ¼
0.03 and deviation from conservation
H
0.090. This approach is explained in detail and illustrated by means of other
applications in a large number of publications including Lovejoy et al.( 2008 ),
Lovejoy et al. ( 2001 ), Schertzer and Lovejoy ( 1991a ), Schertzer and Lovejoy
( 1997 ), Schertzer et al. ( 1997 ) and Lovejoy and Schertzer ( 2013 ). The codimension
C 1 , which characterizes sparseness of mean field, and deviation from conservation
H can be derived as follows. First a log-log plot of the so-called “first order structure
function” ( cf . Monin and Yaglom 1975 ) is constructed (Fig. 12.34 ). Successive
moments are obtained for absolute values of differences between concentration
values for points that are distance h apart by raising them to the powers
¼
Search WWH ::




Custom Search