Saturday, February 19, 2011

Another Follow-Up, on the Subject of Gold...

on a previous post (January 19, 2001) I copied a post from my other blog, on the presence of gold in a local stream. Just a small amount, judging by the tiny grains I have seen so far, but it is gold, nonetheless. The small, unnamed creek is a small tributary of the Chattahoochee River and the place I usually pan is about 1/4 mile from the river.

Now that I have had some time to think about it and revisit the place several times, there are two likely sources for the gold. It should be noted that this area is within a geologic feature called the Brevard Fault Zone (or Brevard Zone of Cataclasis), which has been (at various times) interpreted as a thrust fault, a normal fault, or as a large strike-slip fault. The rock types around here are mylonites, phylonites, muscovite button schists, sheared gneisses, quartzites, garnet muscovite schists, graphite schists,...things that wouldn't normally suggest the presence of gold.

The only thing I have seen along this particular creek (I need to explore more of the creek) that might be a likely source of gold is; 1) A siliceous, brecciated zone, with eroded, angular cavities in the rock suggesting past (sulfide?) mineralization; or 2) Eroded, old Chattahoochee River gravels and sands.

What remains is for me to "pan my way up" the creek to the point where the gold stops, i.e., I am upstream of the source. There are several branches of this creek, which cris-crosses several local roads, but there are enough wooded areas where I can collect sand samples, to take home for refinement panning. I use a screen atop a small bucket to sieve out the gravel and larger sand, leaving fine- to medium-grained sand within the bucket (which is obviously easier to carry).

I hope to get at least some of the searching over with before snake season begins.

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