While surveying well above timberline, I came across this interesting stone.?ÿ The rock is a quartz monzonite porphyry with phenocrysts of Carlsbad-twinned orthoclase in a fine-grained groundmass.?ÿ In layperson terms that means it is a quartz-rich rock that is close to granite in its composition with large visible crystals of a potassium-rich feldspar.?ÿ The squarish holes in the stone are casts of pyrite crystals that were weathered from the rock.?ÿ This chemical weathering is common for granitic-like rocks near hydrothermal mineralized veins.?ÿ Specifically the weathering is called QSP alteration, which stands for chemically altered quartz-sericite-pyrite (sericite is a microcrystalline mica mineral).
Of far more interest to surveyors, I found this stone laying (or is it lying) on the ground near the common corner of two mineral surveys.?ÿ The first two photos show the side of the stone chiseled for Cor. No. 3 of Sur. No. 165.?ÿ The last two photos are of the opposite side of the stone which is Cor. No. 7 of Sur. No. 166.?ÿ
The stone was initially set in 1874 to monument Cor. No. 3 of Sur. No. 145 and Cor. No. 7 of Sur. No. 146. The survey orders were cancelled by the GLO and reissued as Sur. No. 165 and Sur. No. 166. The first two photos clearly show a "6" chiseled over a "4" to correct the mineral survey number. No sense in discarding the old stone. Since I did not find the stone occupying the original corner, I included it in the mound of stone. I wanted to avoid another surveyor thinking that my pin and cap were set at the original corner position, so did not bury it upside down as a memorial. Nor did I wish for anyone that visits the corner to miss seeing the unique chiseling of the original stone.
?ÿ
Cor. No. 3
?ÿ
Cor. No. 7
?ÿ
A few years ago, I found these two stones in a waste pile next to an old mine a little further up the hill.?ÿ They were Cors. Nos. 1 and 4 of Sur. No. 166.?ÿ A smidgen of Colorado precipitation works just as well as Texas chalk to bring out the chisel marks.?ÿ Again this was originally Sur. No. 146.?ÿ I won't bore folks with detailed descriptions other than Cor. No. 1 is a Leadville limestone and Cor. No. 4 is a banded granitic gneiss.
?ÿ
Cor. No. 1
?ÿ
Cor. No. 4
GNEISS!!!!!!!
?ÿ
And it is in fact lying on the ground, I'm constantly making this egregious mistake by telling the dog to lay down and then my smarter half reminds me I'll be lying on the couch if i keep it up.....?ÿ?ÿ ;)?ÿ Awesome share, thank you!
A stone laying on the ground is having sex according to an English Professor decades ago.
sounds like the corner is caught between a rock and a hard place!
GNEISS!!!!!!!
?ÿ
And it is in fact lying on the ground, I'm constantly making this egregious mistake by telling the dog to lay down and then my smarter half reminds me I'll be lying on the couch if i keep it up.....?ÿ?ÿ ;)?ÿ Awesome share, thank you!
I thought you might like the photos Jitterboogie.?ÿ The stones are on the east side of the southern spur of Mt. Bross (above Mineral Park and south of the Dolly Varden Mine).
<iframe width="560" height="315" src="https://www.youtube.com/embed/15jpAclXrnY" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
Now you KNOW I was going to LIKE this post, right?! ??ÿ
