Fortymile project;
Surveys can be found on the website. Surveys have been conducted for most of the mining districts. A link to the project report download can be found. Other Links to downloads for all of the documents related to the survey as well as recompiled updates can be found.
Remote prospectors must be willing to spend time beforehand;
Over the course of several years, I spent hundreds of hours going from one survey line to the next looking at data that was compiled. The survey shows almost different parameters that were measured. The survey began on the western side of the survey area. Survey lines were flown from north to south in alternating directions progressing toward the east. The helicopter flies at an average speed of around 90 miles per hour. That's a speed of about 120 feet per second. Measurements are made at a rate of 10 per second. That means data is acquired every 12 feet along the flight line. Occasionally, flight lines are reflown.
The points where data is acquired are called "stations". The stations are numbered from 0 to the end of the flight line. When I refer to hits, I will reference the flight line and the station on that flight line.
I often plot hits based on a Datum called WGS-84. The survey was flown using a datum called NAD-27. That creates an error in location of 100 to 500 feet. I also use an online mapping service. The hits can be plotted using the same Datum (NAD-27) as used in the survey. The exact location of hits probably is not critical. That's because a "deposit" is large.
When Remote Prospectors are using GPS for locating hits, it's important to know what the Datum is and set up the GPS receiver for the same Datum.
Armed with a GPS receiver, properly setup, prospectors can navigate their way to hits.
So, stick around!
- Geowizard
