Building drillhole databases and 3D modeling for a gold-silver mine

Using voluminous historical documentation, MDA-RESPEC built comprehensive drill-hole databases in 2017 for each of the two deposit areas that comprise the project.  These databases have subsequently been continually updated and subjected to extensive additional verification by Integra and MDA-RESPEC.

Three-dimensional models of late 1880s to early 1900s underground workings were created using original hand drawn long sections and plan maps from the historical high-grade mine.  These models were then transformed from the old mine grid into UTM coordinates.  As-built topographies that reflect open-pit mining undertaken from the late 1970s through to the late 1990s were also created.  These products, as well as new drilling and detailed geologic interpretations by Integra, were then incorporated into updated, highly detailed, Indicated-level gold and silver resource estimations of the two epithermal gold-silver deposits that presently comprise the project.  Three-dimensional modeling of the oxidation state of the mineralization of each deposit was also undertaken, which adds critical context to the application of the metallurgical test results that are being generated by Integra.

The updated modeling formed the basis of a recently disclosed preliminary economic assessment, the technical report for which was published under MDA-RESPEC letterhead on Oct. 22, 2019.