eEight International Geostatisitcs Congress, Chile, 2008

1. Application of categorical variables to improve estimation in the Amapari Lateritic Gold Mine, Brazil Francisco J. da Silva(UFRRJ) Luis P. Braga(UFRJ) Claudio G. Porto(UFRJ) Alfredo R. Nunes(MPBA) Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

2. DATA Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

3. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

4. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 The Amapari gold mine is situated in the Amapá Estate, North Brazil, where humid equatorial climatic conditions prevail. Under these conditions weathering is extremely aggressive resulting in thick regolith profiles of lateritic nature where the gold distribution differs substantially from that observed in the fresh ore.

5. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 The complexity of the lateritic profile is due to the multiform characteristics of the alteration process which makes it difficult to properly define geological boundaries.

6. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 The redistribution of the gold grades due to weathering factors creates a geometry for the mineralization which hardly conforms with mapeable units in a more traditional sense. In reality, the alteration process creates an intricate geological framework which strongly conditions the spatial modelling.

7. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

8. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

9. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

10. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

11. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 CLUSTERING

12. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

13. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

14. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

15. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

16. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 Cluster1: 775 cases Cluster2: 3,504 cases

17. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 VARIOGRAM MODELLING

18. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 Cluster1

19. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 Cluster2

20. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 Cluster1 + Cluster2

21. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 VALIDATION

22. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

23. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 1 VALIDATION BLOCK F HOLE CLUSTER 1 F HOLE CLUSTER 2 FD HOLE (“TRUE VALUE”)‏

24. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 1 VALIDATION BLOCK F HOLE FD HOLE “ TRUE VALUE” USUAL KRIGING NEIGHBOURHOOD (KP)‏ F HOLES

25. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 1 VALIDATION BLOCK F HOLE CLUSTER 1 F HOLE CLUSTER 2 FD HOLE “ TRUE VALUE” CLUSTER 2 BASED NEIGHBOURHOOD (KMCKP)‏

26. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 1 VALIDATION BLOCK F HOLE CLUSTER 1 F HOLE CLUSTER 2 FD HOLE “ TRUE VALUE” CLUSTER 2 BASED NEIGHBOURHOOD (KMCKP)‏

27. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 1 VALIDATION

28. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 1 VALIDATION

29. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 1 VALIDATION

30. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 2 VALIDATION

31. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 2 VALIDATION BLOCK “ TRUE VALUES” F HOLE CLUSTER 1 F HOLE CLUSTER 2 FD HOLE TRUE VALUES = KRIGING BLOCK VALUES F + FD HOLES

32. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 2 VALIDATION BLOCK “ TRUE VALUES F HOLE USUAL KRIGING NEIGHBOURHOOD (KP)‏ F HOLES

33. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 2 VALIDATION BLOCK F HOLE CLUSTER 1 F HOLE CLUSTER 2 CLUSTER 2 BASED NEIGHBOURHOOD (KMCKP)‏

34. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 2 VALIDATION BLOCK F HOLE CLUSTER 1 F HOLE CLUSTER 2 CLUSTER 2 BASED NEIGHBOURHOOD (KMCKP)‏

35. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 2 VALIDATION

36. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 SET 2 VALIDATION

37. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 CONCLUSIONS

38. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

39. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008

40. Eight International Geostatistics Congress. Santiago, Chile, December 1-5, 2008 THANK YOU !