Page 177 - Geochemical Anomaly and Mineral Prospectivity Mapping in GIS

178 Chapter 6

TABLE 6-V

Results of distance correlation calculations to quantify spatial association between occurrences of
epithermal Au deposits and intersections of NNW- and NW-trending faults/fractures, Aroroy
district (Philippines). Table entries in bold pertain to optimal spatial association.

AP Y max (m) r d jx d jy t-value* Proximal- r d jx d jy Distal- r d jx d jy
r
j
C 800 0.9765 15.075 0.9443 0.8399
N 800 0.9928 27.528 0.9837 0.9446
NE 600 0.9916 25.491 0.9835 0.9197
E 600 0.9776 15.404 0.9437 0.7355
SE 800 0.9958 35.928 0.9913 0.9705
S 900 0.9969 42.306 0.9923 0.9749
SW 800 0.9908 24.291 0.9765 0.9212
W 800 0.9869 20.250 0.9741 0.9191
NW 800 0.9980 52.751 0.9952 0.9758
*Calculated values of r d jx d jy are significantly different from zero; the critical t-value at

α=0.001 and ν=13-2=11 degrees of freedom is 4.025 (Davis, 2002).

trending faults/fractures shows that seven (or 54%) and ten (or 77%) of the 13
epithermal Au deposits are within 0.8 km and 0.9 km of intersections between NNW-
and NW-trending faults/fractures, respectively. These results are similar to the results of
the distance distribution analysis (see Figs. 6-10A and 6-10B).
Table 6-VI and Fig. 6-14D indicate that there is positive spatial association between

TABLE 6-VI

Results of distance correlation calculations to quantify spatial association between occurrences of
epithermal Au deposits and NE-trending faults/fractures, Aroroy district (Philippines). Table
entries in bold pertain to optimal spatial association.

AP Y max (m) r d jx d jy t-value* Proximal- r d jx d jy Distal- r d jx d jy
r
j
C 300 0.9926 27.094 0.9902 0.9513
N 300 0.9996 118.041 0.9993 0.9959
NE 300 0.9995 102.544 0.9993 0.9953
E 300 0.9857 19.433 0.9822 0.9138
SE 300 0.9986 62.821 0.9977 0.9893
S 300 0.9990 74.858 0.9983 0.9926
SW 300 0.9993 92.141 0.9989 0.9968
W 300 0.9989 71.849 0.9973 0.9901
NW 300 0.9991 76.211 0.9983 0.9917
*Calculated values of r d jx d jy are significantly different from zero; the critical t-value at
α=0.001 and ν=13-2=11 degrees of freedom is 4.025 (Davis, 2002).