Gullrock - how to read parts per billion background gold ``The soil geochemistry survey consisted of 535 samples of B-horizon soils located immediately east of Gullrock Lake`` Gullrock`s gold was found in the ``B-horizon``, which is subsoil. It means the samples came from below the topsoil. One method they (Murgor, in 2014) could have used to gather the samples is shallow overburden drilling (just a few feet down, through the topsoil, into the subsoil).
The environment might look something like this:
Link, if......:
https://dr282zn36sxxg.cloudfront.net/datastreams/f-d%3Abbbfaa5db2d1fc88f80b54dc3aedc63f5db6e0bf7e89965b0033d1ab%2BIMAGE_THUMB_POSTCARD_TINY%2BIMAGE_THUMB_POSTCARD_TINY.1 The topsoil could be newer (displaced) soil (without gold, and arriving after the gold was disbursed to the surface). B-horizon subsoil could represent older soil - more representative of contents residing further below.
The gold findings in Gullrock`s B-horizon subsoil could suggest glacial smearing of gold from buried bedrock gold occurences. Maybe looking something vaguely like this:
Link, if.....:
https://vermilliongold.com/wp-content/uploads/2013/12/linden_grains.png Either way, it would be wise for us to hunt down the source of our subsoil gold. Something (more solid) nearby or below has suppiled the gold. I read that typical background values for tills in the area is around 3 parts per billion - .003 g/t Au.
I think the background gold values in (Gullrock`s) Anomaly A to D convert over to:
A - .002 to .035 g/t Au
B - .002 to .040 g/t Au
C - .002 to .028 g/t Au
D - .007 to .032 g/t Au
1) Anomaly A
- 500m of strike length and up to 100m in width (open to the west).
- Gold values from 2 to 35 times background.
2) Anomaly B
- 500m of strike length and up to 150m in width.
- Gold values from 2 to 40 times background.
3) Anomaly C
- Complex shape anomaly 300m x 250m in size.
- Gold values from 2 to 28 times background.
4) Anomalies D (east and west)
- Each 100m of strike length and up to 50m in width.
- Gold values from 7 to 32 times background.