Orex Silver - Sandra Escobal Project

Orex Minerals (www.orexminerals.com) have been announcing some excellent drilling results from their Sandra Escobar project (optioned from Canasil Resources) located in Durango, Mexico.

Silver is hosted in an altered and highly permeable volcaniclastic rock that contains disseminated silver bearing minerals with broadly spaced stockwork veinlets, and recent results include intercepts of 32 meters grading 255 g/t silver, which looks excellent.

But we can do a huge amount of things with the data that has been included in the various press releases, presentations and on Orex's website about this project.

So let us see how good Sandra Escobar really is!

Methodology

• Drill-hole data was obtained from the various press-releases on the Orex website (link). The grades were calculated from the press releases and processed with Exploration Insights and Corebox’s Drill-hole Interval calculator (link).
• This provides accurate (but not exact) data on the residual grade of the hole intercepts if we remove the effect that narrow high grade intervals will have on the overall grade of the hole.

Data sources

• Assay data was sourced from the various Orex press releases and processed using the drill hole interval calculator to work out the residual grade (i.e. the grade of the holes not being skewed by the narrow, high grade zones) for each drill-hole.

• Drill-hole data was digitized from maps and sections provided by Orex that they included in presentation and with the press releases.

  • hole direction, dip and depths were not included in the press releases but has been estimated from the various cross sections provided 

•  Topography was downloaded from the Instituto Nacional de Estadistica y Geografia (INEGI - link) that provide topo maps and digital elevation models for all of Mexico.

• Air photos were obtained from Google Earth.

 This data was brought into Leapfrog Geo so that it could be displayed in 3D and we can see all of the data together, and pictures are so much easier to understand!

 

 Figure 1: Hole location and topography.

 

Figure 2: Cross Section A

 

Figure 3: Cross Section B

 

Figure 4: Cross Section C

We can see that silver grades are highest close to the surface, which probably suggests that it has been enriched by supergene processes (percolating groundwater moving and concentrating silver close to surface).

 We can model up the silver zone and build a grade model from the data included in the press releases.

 

 

The grey solid shows is what we think the extents of the silver horizon, where it hasn't been drilled, and the colored areas show the estimated grades of this zone where it has been drilled by Orex. We see that the highest grades drilled to date are where the the silver zone is closest to the surface, it appears that silver grades are decreasing with depth.

However, we can also gauge the potential of the mineralisation, we can quickly see that it is open to the NW, SW and S, demonstrating that the area that has been drilled to date is only a small part of potentially a very large zone.

We've also created a Leapfrog viewer file (link) of all of this data for you to download and view it for yourself. All you need is to do is download the free Leapfrog Viewer application (link), install it and go from there.