KAT Exploration Inc (KATX)

[ShortonCash]

between two boreholes, hence provide
additional information on the nature of the deposit

Maybe two bore holes are enough.....cuts the time frame way down....

3D stochastic inversion of gravity data using cokriging and cosimulation

Geological Survey of Canada, Continental Geoscience Division, Ottawa, Ontario, Canada. E-mail: [e-mail]

A new application has been developed, based on geostatistical techniques of cokriging and conditional simulation, for the 3D inversion of gravity data including geologic constraints. The necessary gravity, density, and gravity-density covariance matrices are estimated using the observed gravity data. Then the densities are cokriged or simulated using the gravity data as the secondary variable. The model allows noise to be included in the observations. The method is applied to two synthetic models: a short dipping dike and a stochastic distribution of densities. Then some geologic information is added as constraints to the cokriging system. The results show the ability of the method to integrate complex a priori information. The survey data of the Matagami mining camp are considered as a case study. The inversion method based on cokriging is applied to the residual anomaly to map the geology through the estimation of the density distribution in this region. The results of the inversion and simulation methods are in good agreement with the surface geology of the survey region.[/b

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http://meetingorganizer.copernicus.org/EGU2010/EGU2010-13289.pdf

In the mining industry, classic methods to build a grade model for ore deposits are based on kriging or cokriging
of grades for targeted minerals measured in drill core in fertile geological units.
As the complexity of the geological geometry increases, so does the complexity of grade estimations. For example,
in layered mafic or ultramafic intrusions, it is necessary to know the layering geometry in order to perform kriging
of grades in the most fertile zones.Without additional information on geological framwork, the definition of fertile
zones is a low-precision exercise that requires extensive experience and good ability from the geologist.
Recently, thanks to computer and geophysical tool improvements, seismic tomography became very attractive
for many application fields. Indeed, this non-intrusive technique allows inferring the mechanical properties of the
ground using travel times and amplitude analysis of the transmitted wavelet between two boreholes, hence provide
additional information on the nature of the deposit.

The results obtained from the stochastic tomography improve considerably the understanding of the geological
framework of the ground between boreholes. However, the commonly used algorithm like LSQR give a
useless result.
Lastly, the Bayesian approach has shown realistic results for the nickel, copper and cobalt estimations

.

Using stochastic borehole seismic velocity tomography and Bayesian
simulation to estimate Ni, Cu and Co grades.
Lorenzo Perozzi (1), Erwan Gloaguen (1), Stephane Rondenay (2), André Leite (3), Glenn McDowell (3), and
Robert Wheeler (3)
(1) Institut National de la Recherche Scientifique, INRS-Eau, Terre et Environnement, Université du Québec, Québec, Canada,
(2) Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, United
States, (3) Vale Inco, Toronto, Canada