Correlation, Method of Least Squares, Linear Regression and the General Linear Model - Geomathematics: Theoretical Foundations, Applications and Future Developments - page 127

Table 4.4 Abitibi area; Variables selected by stepwise regression (Q¼0.5) of logarithmically
transformed copper per (10 10 km) cell on 55 geological and geophysical variables

Q

Rank Name of variable value Regression coefficient

0.14863

0 Constant term

0.36 · 10 9 1 Acidic volcanics mafic volcanics 0.00045

0.44 · 10 4 2 Granitic rocks acidic volcanics 0.00147

0.70 · 10 3

3 Acidic volcanics sediments 0.00182

0.45 · 10 4 4 Acidic volcanics iron formations 0.00334

0.63 · 10 3

5 Acidic volcanics aeromagn. anomaly 0.01958

0.14 · 10 3 6 Mafic intrusions acidic volcanics 0.00187

0.87 · 10 3 7 Metamorphic rocks iron formations 0.00618

0.91 · 10 2

8 Mafic intrusions metamorphic rocks 0.00129

0.32 · 10 1 9 Granitic rocks sediments 0.00037

10 Sediments Bouguer anomaly 0.13 0.00027

11 Mafic volcanics sediments 0.021 0.00017

12 Acidic volcanics 0.13 0.05068

13 Sediments aeromagnetic anomaly 0.12 0.00560

14 Sediments 0.14 0.01726

15 Ultramafics sediments 0.27 0.00049

16 Granitic rocks iron formations 0.30

17 Iron formations Bouguer anomaly 0.10 0.00490

18 Iron formations 0.19 0.40777

19 Mafic volcanic iron formations 0.09 0.00171

- Backward pass, No. 16 deleted 0.65
19 Iron formations aeromagn. anomaly 0.20 0.02133
20 Ultramafics iron formations 0.29 0.00332
21 Sediments metamorphic rocks 0.36 0.00025
22 Acidic volcanic methamorphic rocks 0.29 0.00123
23 Mafic intrusions mafic volcanics 0.41 0.00026
24 Granitic rocks 0.38 0.00128
25 Granitic rocks mafic volcanics 0.44 0.00003
26 Mafic intrusions sediments 0.50 0.00030
Figure 3.8 a was based on this run. The rank of the first 16 variables selected is the same as that
obtained by forward selection used for Fig. 4.10 (Source: Agterberg 1974 , Table L)

4.4.1 Incorporation of Recent Discoveries

Lydon ( 2007 ) has published a comprehensive overview of the economic and
geological contexts of Canada's major mineral deposit types accompanied by a
DVD with production and estimated reserves of Canadian mineral deposits includ-
ing large copper deposits in the Abitibi area. Between 1977 and 2007, there were
five major new discoveries (Ansil, Bouchard-Hebert, Bousquet-Laronde, Amos and
Louvicourt deposits), all within the vicinities of the 48 deposits known to exist in
1977. Revising our original 1968 data set (Agterberg et al. 1972 , Appendix 1) using
Lydon's data set, and including one 2008 estimate for the newly discovered Upper
Beaver ore zone near Kirkland Lake, Ontario (cf. www.queenston.ca/news/pdf/
080922.pdf ) , yields a combined set of 66 copper deposits containing 9.50 Mt Cu,