Monday, May 2, 2016

My methodologies - part 1 - data sources

My methodology

 For most (if not all) of these projects I will not have had the chance to visit them, look at the drill-core, the surface geology or speak with the geologists associated with them. Essentially, I have access to exactly the same information that you do.

So, I wanted to write a series of posts explaining my data sources and methodologies I use to extract and interpret data from the various projects and prospects that will form the base for the posts on this blog.

Data sources

All of the data I use for my interpretations and to create 3D views for a project are obtained from public sources:
  • Drill-hole data: derived from technical reports, presentations and press releases.
  • Satellite images: sourced from Google Earth
  • The USGS public global topography data through their Earth Explorer website (link)
  • Surface data (e.g. geology maps, geophysics and geochemistry): technical reports etc.

     The geological and Ordnance surveys of many countries provide a large amount of free to download geography and geology data (e.g. geology maps, topo maps, stream sediment data etc.).

I’ll try to include a full list of data sources with my posts and any useful links, which I’ll add to the useful lists.

Drill-hole data

To be plot the drill-holes and see the drilling data in 3D you need 3 pieces of information:

  • Hole location - the Easting (x), Northing (y) and elevation (z) of where the hole was drilled from.
    • Generally this information is included in technical reports, but for new drill-holes I often have to  digitize the hole locations from plan maps included in press releases.
    • The elevation data is sometimes not included, but I can use the topo surface to create a relatively accurate elevation for each drill-hole.
  • The direction the hole was drilled (hole orientation)
    • This information is rarely included with press releases
    • I have to manually measure the hole orientations from plan maps in press releases.
  • The angle at which the hole was drilled (the angle of Dip)  
    • This information is generally not included in press releases. Occasionally this data is included in a "start of drilling" PR.
    • Typically this data is obtained from cross sections and plan maps that accompany PRs.
  • Hole length (the hole depth, or Target Depth).
    • Rarely included in press releases
    • I can measure a hole length from a cross section, or if I can’t do this, I’ll simple take the deepest assay interval and extend the hole 50m beyond it.

Data accuracy: Any data I have to digitize/measure is generally of medium quality and will have an error (depending on the map scale and quality of the images I work with) of between 5-20m.

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