Thursday, May 31, 2018

The Freaking Magnificent Great Unconformity

There is a geologic zone in the Grand Canyon scientists call the Great Unconformity but I have a friend that prefers to call it the Freaking Magnificent Great Unconformity.  I just got back from the Grand Canyon where I rafted from Lee’s Ferry to Phantom Ranch. A story is on its way about the Grand Canyon even though it's not exclusively from the Grand Canyon. I thought about this on the river often.

Redwall Cavern.
1.7 billion years ago, the earth had mostly cooled and the part of the earth we now call northern Arizona was likely under the sea but it isn't known. There strata in the inner gorge is composed of Zoroastrian Granite and Vishnu Shists, igneous rocks from the mantle of the earth. All those rocks with Hindu names haven’t done a damn thing in the last billion years or so except rise and fall with whims plate tectonics. Life wouldn't be around for a long time. When life rolled around at about 600 million years ago, Northern Arizona was under the sea. Sedimentary rocks formed on top of the shists and granites and they have microscopic fossils. As you walk up canyon the fossils get larger and more complex. There are “unconformities” in the layers that are basically places where millions of years are missing. The Great Unconformity is a place where 545 million year old Tapeats Sandstone rests on top of the Chuar group of Pre-Cambrian Rocks dating 825 million to a billion years old. Either no rock formed for about 400 million years or rock formed that was later eroded away. Either way, eons disappeared from the geologic story. There is a side canyon of the Grand called Nautiloid Canyon with fossilized nautiloids like those on my tattoo. Higher up in the canyon there are dinosaur fossils in places. After that evolution tottered. Life hasn't improved. Nothing tops the Velicoraptor, present company included. 

Nautiloid Fossil, Nautiloid Canyon.
Time moved along and the sea floor rose and the Colorado River was born as a meandering tropical river on a vast coastal plain much like the Amazon today. With time, the North American Tectonic Plate rose to 7,000 above sea level. The river stayed put at lower elevation but the land kept rising. The Grand Canyon was cut much like if you placed a knife on top of a cake and lifted the cake with the knife not moving. The river didn't cut down a mile deep but it did cut. The Kaibab Plateau rose and the river stayed put. 

Sometime after the mastodons went extinct and before the humans go extinct, I came along and rowed down the river in a rubber raft. I got back a few weeks ago. How is that act of running a river or my existence important in a grand scheme (pun intended) that includes Nautiloid fossils encased in rock for 300 million years? 

Once you find out you’re meaningless, 
you want to spend as much time under a waterfall as possible.Sydney at Stone Creek Falls

Every night I laid on the ground looking at stars so old and so far away that some of them could have died back when the velociraptors went extinct. The entire time span of the human race is VASTLY shorter than the Great Unconformity. Millions of species rose to existence and went extinct leaving no noticable trace of their existence. For a moment chew on the thought that eons can vanish from the face of the earth and that humanoids have been around for about 2 million years.









Life is short, do this whenever you can. Elevs Chasm.



All trace that humans ever existed could disappear from the planet with vastly more ease than not. What silliness it is for us to jockey for position in traffic to see who gets to work first to kiss the bosses ass? We want to build a wall to keep Mexicans out but lose sight of the fact that Mexicans and Americans share the North American Tectonic Plate for such a short period of time that it would suck to spend our short existence manufacturing differences or generating unnecessary divisions. I think once my shoulder I will learn how to play Mexican guitar. Considering how insignificant we are compared to geology, rowing rafts, climbing rocks, and camping out with friends makes a lot more sense to me than most anything else. 

My life matters a lot but only to me and to others that care about me. The universe is too big and the fossils too old to fret too much about the details.









In the vicinity of the Great Unconformity.

Tomorrow surgeons fix my shoulder but it involves considerable cutting. No climbing for me for a while. Maybe when I can climb again, I will head to one of the side canyons with Zoroastrian granite. Granite is dumb as a rock but in climbing granite that has been there for 1.7 billion years, we can gain wisdom.










I took this photo east of Phoenix near the Superstition Mountains. I drove by the sign, turned around, parked, and took photos of the sign from all angles.























Zoroastrian Granite, Grand Canyon









1 comment:

Vonne said...

Great read Carlos! It brings back memories of the rocks in the canyon. You’ll climb again! ER