But how would I marshall more evidence? I went immediately to the mouth of the adit where there was an accumulation of tons of massive sulfide ore, that had been removed from the mine for purposes of crushing and metallurgical testing. I thought to myself, “Maybe I can spot a specimen of ore rock that reveals transposition.” All the rocks were dark grey to black, but within 15 minutes I picked up a chunk that looked like it could be a winner. That same afternoon I slabbed it (I had made up a portable diamond-bladded saw for work that summer), and discovered what you see here: a beautiful isoclinal intrafolial fold of sulfide ore, complete with axial plane schistosity. This find and what it represented was an important part of interpreting the ore deposit as a syngenetic massive sulfide deposit, originally deposited as a ‘strange’ rock type on the seafloor bottom in a volcanic arc setting.
Age & Formation
Tetagouche Group of Ordovician age, ~420 Ma.