San Celso Epithermal Silver Project, Zacatecas, Mexico
We were asked to create detailed 3D models of the geology and mineralisation for a project that covered a number of Spanish-era silver mines in Central Mexico.
A series of AutoCAD maps of the various mine workings and a number of excel spreadhseets containing the underground sampling data was provided.
Topography was acquired from INEGI (link) as an ArcGIS shp file and was imported into Leapfrog Geo and used to create a 3D topography surface. No surface geology map was provided, but using Google Earth, we were able to identify several additional mineralised structures and the large rhyolite stock that forms a prominant hill in the NW corner of the property.
The spreadsheets for the underground samples brought into Access database and modified so that the sample location and assay data could be linked together when imported into Leapfrog GEO.
WIth all of the data in Leapfrog, we could quickly create a 3D geology model. Each vein was modelled as a separate vein within a vein system, and using the satellite imagery, we could determine the paragenesis and cross-cutting relationships.
The stock was quickly modelled as a vertical intrusion that post-dated and truncated the silver veins.
The sampling data was then used to create a series of grade interpolants for each element to see if there were any trends in their distributions.
Economic mineralisation is found within narrow ore-shoots, that have limited horiontal extents and a distinct vertical trend.
The highest grades appear to be found at vein intersections.
Historic mining has focused on a small section of just 2 of the known veins. Several veins are vessentially unexplored.
Excellent potential to define additional areas of high grade mineralisation below the historic workings as they only exploited the veins to a depth of 120m.
The ability to view and interpret the data from this project in 3D gives us the opportunity to see if there are any distinct trends in mineralisation.
This has allowed us to create a targetted exploraion program to focus on the most prospective areas, that will minimise expenditures but maximise returns.