I just back from Tokyo and I hit the ground running to Utah!
Utah has some of the most stunning scenery in the US, the gems and minerals there are world class and sometimes you stumble upon a super volcano!
While out looking for topaz & beryl I wandered into the Indian Peak Caldera, which was a super volcano that erupted 30 million years ago. For years geologists were puzzled by formations in the area and finally in 2013 students and geologists from BYU put the puzzle pieces together and discovered what may be the world's largest supervolcano.
The line down the center of the image above is the border between Nevada & Utah. The caldera spanned about 30 miles across. The eruption, known as the Wah Wah Springs eruption was 5000 times more powerful than the Mt. St. Helens eruption in 1980 and 30 times more powerful than the 3 super eruptions from Yellowstone. The Wah Wah eruption spewed 5,500 sq. km of magma. The deposits left by the eruption are 15,000 feet in some areas! Scales of this size are hard to imagine.
30 million years of erosion, place tectonics and additional eruptions have made the caldera invisible to the laymen. The new mountain ranges that sit on top of the caldera have some of their own volcanic cones though.
This was one of several massive rhyolite cones left over from past volcanic eras. It sits just on the edge of the Indian Peak Caldera. While I din't find any topaz big enough to take home, there were tiny crystals on the road, I did find some beautiful chalcedony in rhyolite.
Gettin to this spot was a 1 hour drive down dirt road in desolate countryside.
Before heading out to Indian Peak Caldera I spent the morning rockhounding an old open pit mine outside of Cedar City. It's an old iron mine that produces incredible magnetite, hematite, siderite, amethyst and apatite specimens. It's also one of many massive open pit iron mines in the area known as the Iron Mountain District, Iron County.
The main iron ore vein is in the center of the photo. The dar streak on the back wall.
It's a hideous looking thing that measures about 4 feet wide, but inside of it and off to it's sides are awesome mineral specimens.
The white streaks you see in the vein are apatite crystals. Apatite is a yellow/green phosphate gemstone that is pretty mesmerizing when you see it, then again most gemstones are, especially when you dig them yourself.
These apatite specimens are from Mexico.
It's very hard getting the apatite crystals out of the matrix from Utah though. I did find some loose pieces, but I sent them off to Japan today. Here is a terminated crystal and a specimen.
Apatite with siderite covered magnetite.
The triangle crystals are magnetite. They usually form pyramidal crystals like these.
This mine however also produces octahedral magnetite crystals that are much rarer.
The octahedrals evaded me this time, but I know they are there and I will find them some day.
I did find incredible specimens though like this siderite with apatite & magnetite.
The siderite is the brown mineral, greenish/yellow is apatite, black is the magnetite.
I also found specimens with some minerals I can't identify yet as well as amethyst, calcite & bladed hematite.
Calcite pocket in the rock.....
And out of the rock in 1 piece.
I also found onyx which was very strange. It was in the upper workings of the pit and hasn't been reported from this mine yet.
One last detail about this area, the road to this mine was part of the Old Spanish Trail that stretches from Mexico. It's hard to believe the Spanish traveled this far through California and Arizona on horseback to this area. Gold drove men to do crazy things.
I am doing this series backwards. This was my last day in Utah. The next post will be about my second day in Utah mining topaz, red beryl, crunch berries and uranium infused opal.
Here is a good video about the Indian Peak Caldera by BYU geologists.
