I headed up to the high hillsides on nearby Mingus Mountain to collect some specimens of Banded Iron Formation (or BIF as it's often called) which litters the surface around 7000 feet on the mountain top.
BIF is and interesting and very ancient rock composed of alternating layers of red Jasper and black/silvery hematite.
It is theorized that this rock formed approximately 2 billion years ago when the earth was just beginning to develop an oxygen atmosphere. The oxygen reacted with the abundant dissolved iron in the water and would precipitate out and form reddish chery/Jasper silica layers alternating with the reduced blackish iron when the oxygen was depleted-only to repeat the cycle over millions of years.
Now the former coastal deposits sit at almost 7000 feet in elevation on Mingus Mountain.
Similar BIF can be found in South Africa, the upper peninsula of Michigan (which I collected as a teenager in the 1970s) and huge deposits in Australia that have been mined for the iron. The Jetome deposits are some of the oldest and it's fascinating to think that this area was once the edge of a continent but has been thrust upwards by tectonic forces.
I'll probably try to cut and/or tumble some pieces to see how beautiful they are but even in their raw state they are still beautiful and fascinating to me.
