『Abstract
Data-driven prospectivity mapping can be undermined by dissimilarity
in multivariate spatial data signatures of deposit-type location.
Most cases of data-driven prospectivity mapping, however, make
use of training sets of randomly selected deposit-type locations
with the implicit assumption that they are coherent (i.e., with
similar multivariate spatial data signatures). This study shows
that the quality of data-driven prospectivity mapping can be improved
by using a training set of coherent deposit-type location. Analysis
and selection of coherent deposit-type locations was performed
via logistic regression, by using multiple sets of deposit occurrence
favourability scores of univariate geoscience spatial data as
independent variables and binary deposit occurrence scores as
dependent variable. The set of coherent deposit-type locations
and three sets of randomly selected deposit-type locations were
each used in data-driven prospectivity mapping via application
of evidential belief functions. The prospectivity map based on
the training set of coherent deposit-type locations resulted in
lower uncertainty, better goodness-of-fit to the training set,
and better predictive capacity against a cross-validation set
of economic deposits of the type sought. This study shows that
explicit selection of training set of coherent deposit-type locations
should be applied in data-driven prospectivity mapping.
Keywords: Cumulative frequency distributions; Logistic regression;
Evidential belief functions; GIS; Alkalic porphyry Cu-Au; Structural
controls; Geophysics; Geochemistry; British Columbia (Canada)』
1. Introduction
2. The test area and geoscience spatial data sets
3. Mineral occurrence favourability scores of univariate geoscience
spatial data
3.1. Deposits excluded from the analysis
3.2. Univariate derivative geoscience spatial data used in the
analysis
3.3. Analysis of spatial association
3.4. Results and discussion
4. Analysis and selection of coherent deposit locations
4.1. Concept
4.2. Logistic regression analysis
4.3. Results and discussion
5. Data-driven prospectivity mapping
5.1. Evidential belief functions
5.2. Training deposit locations
5.3. Thematic evidential data layers
5.4. Data-driven estimation and integration of EBFs
5.5. Estimated EBFs of evidential data layers and integrated
EBFs
5.6. Performance of prospectivity maps
6. Discussion
7. Conclusions
References