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Buju
Trad climber
the range of light
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Dec 26, 2009 - 01:01pm PT
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Hey Bryan!
My name is Roger and Greg may have mentioned to you about the work I have done for him both maping both morraines and the rock types of El Cap. I work and live in Tuolumne in the summer and would love to take a walk with you somtime and check out those beautiful features you have posted pictures of (I have a few pretty little nuggets I could show you myself). I hope to be in graduate school in about a year to continue with geology and would love to pick your brain.
Im on the east coast right now and unfortunatly ahve no acess to a TV and missed the show. congratualtions to all of you guys for getting the word out!
-Roger
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domngo
Trad climber
Ottawhere, Ontariwho
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Dec 26, 2009 - 01:08pm PT
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Hey Guys,
For anyone that missed the show you can catch it here at:
http://www.ninjavideo.net/cat/1492
along with the entire 1st and 2nd seasons. Just make sure you open the helper beta 0.3.10 at the top of the page or else you'll get an error for the video.
p.s. divx is needed
dom
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Minerals
Social climber
The Deli
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Topic Author's Reply - Dec 26, 2009 - 11:13pm PT
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Hey Roger!
I don’t remember Greg mentioning your name, but that doesn’t mean that he didn’t. I would love to help out more with mapping the SE face of El Cap – what an awesome project! I know that Greg has been pretty busy with stuff, but maybe at some point we can all look through some photos and walk the base.
Yeah, if you will be in Tuolumne again next season, we should certainly meet up and check out some cool rocks! I’d be psyched to see the areas that you know of too! Seems like I’m starting to run out of new areas to hike and geologize, short of doing overnight backpack trips.
Domngo, thanks for posting the link for the videos!!! It works! :) I was able to see the “Flash” version without any updates. Cool!
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Captain...or Skully
Social climber
Top of the 5.2-5.12 Boulder
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Dec 26, 2009 - 11:16pm PT
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Mmmmmmmm, geologizing.
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Minerals
Social climber
The Deli
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Topic Author's Reply - Dec 26, 2009 - 11:17pm PT
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WHAT…? You want more messed up metamorphic rock photos…?
OK!!!
Most of these photos have no object for scale (scale card, hammer, etc.); they are more artistic than scientific. Enjoy!
The following photos are from the May Lake area, Tuolumne. These metasedimentary rocks are over 500 million years old and have literally been to Hell and back. This “roof pendant” and other metamorphic rocks on the west side of the Tuolumne Intrusive Suite are part of what is called the Snow Lake block, a large section of the Earth’s crust that was carried about 400km northward along the Early Cretaceous, right-lateral Mojave-Snow Lake fault by tectonic forces. Some of these deformed sandstones are probably related to the Zabriskie quartzite in the Death Valley area and the Tapeats sandstone in the Grand Canyon area.
Foliation in metasedimentary rock
Foliation:
http://en.wikipedia.org/wiki/Foliation_(geology);
Metasedimentary rock
Metasedimentary rock and deformed granitic dikes
Folded metasedimentary rock
Folds:
http://en.wikipedia.org/wiki/Fold_(geology);
Offset bands in metasedimentary rock/migmatite
Metasedimentary rock/migmatite
Folded metasedimentary rock/migmatite
Folded metasedimentary rock/migmatite
Ptygmatic folding in metasedimentary rock
Migmatite:
http://en.wikipedia.org/wiki/Migmatite
148 million-year-old Independence Dike Swarm dike (dark rock) hosted in white marble, just outside of the western margin of the Tuolumne Intrusive Suite. This is another roof pendant sliver of metasedimentary rock, similar to what is exposed around May Lake
More info on the Independence Dike Swarm:
http://www.geolab.unc.edu/Petunia/IDS_Web_Site/FTG.html
http://gsa.confex.com/gsa/2003CD/finalprogram/abstract_51567.htm
The following photos are from the east side of the Tuolumne Intrusive Suite, in the Saddlebag Lake/Steelhead Lake areas, just outside of Yosemite NP. These metamorphic rocks are both volcanic and sedimentary in origin, and are younger than the metasedimentary rocks on the west side of the Tuolumne Intrusive Suite.
Strong foliation/lineation in metavolcanic rock; notice the alignment of the long axis of mineral grains
Folded phosphate layers in deformed siltstone, near Bennettville, behind Tioga Pass Resort
Banded metasedimentary rock on left, megacrystic Cathedral Peak granodiorite on right; this is a section of the contact between the Tuolumne Intrusive Suite and metamorphic “roof pendant” rocks to the east, Steelhead Lake area
Tightly-banded metasedimentary rock, offset by numerous brittle fractures, Steelhead Lake area
Tightly-banded metasedimentary rock, cut by secondary epidote veins (green); notice quartz-filled fractures in central epidote vein and clockwise rotation of individual segments during deformation, Steelhead Lake area
Tightly-banded metasedimentary rock, cut by aplite dike; both metavolcanic rock and dike are cut by younger, epidote-filled fractures
Epidote:
http://en.wikipedia.org/wiki/Epidote
Boudinaged granitic dike in well-foliated metavolcanic rock; the dike formed parallel to foliation and was subsequently stretched, squished, and pinched into separate segments during metamorphism; Shepherd’s Crest (granitic) in upper left section of photo
Boudinage:
http://en.wikipedia.org/wiki/Boudinage
Stretched-pebble conglomerate; pebbles/cobbles were deformed and stretched/flattened during metamorphism
Stretched-pebble conglomerate and bands of metasandstone/siltstone; pebbles/cobbles were deformed and stretched/flattened during metamorphism
Ptygmatic folding of granitic dikelet in stretched-pebble conglomerate
Deformed potassium feldspar (orthoclase) megacrysts along the contact of metavolcanic rock and Cathedral Peak granodiorite; notice the brittle offset of megacrysts along their centerline (Carlsbad twin plane), Cascade Lake shear zone, Steelhead Lake area
Got all of that??? ;)
Edit: My first two Wiki links don’t work – please cut and paste. (Damn parentheses…)
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TGT
Social climber
So Cal
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Dec 26, 2009 - 11:22pm PT
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Now THAT'S!!
Geoporn!
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Mighty Hiker
climber
Vancouver, B.C.
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Dec 26, 2009 - 11:25pm PT
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Some of Bryan's fascinating features may be in this photo of May Lake, from October 2008. Saw all sorts of interesting things while doing the traverse (loop hike) to it. Even at such a small scale, you can tell that rock's been bent, folded, mutilated and cooked.
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tuolumne_tradster
Trad climber
Leading Edge of North American Plate
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Dec 26, 2009 - 11:55pm PT
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AWESOME XXX Geoporn! Many thanks for those photos...especially the Snow Lake block photos. I didn't realize that there's Cambrian quartzite in the May Lake area. I'll have to hike up there next summer to check out those outcrops.
I've run across a lot of meta-volcanic rocks with epidote veins in the Mt Dana area and Cecile Lake near the Minarets. I think they're associated with Permo-Triassic collapsed calderas?
Are you putting "roof pendant" in quotes because you interpret these rocks differently?
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Captain...or Skully
Social climber
Top of the 5.2-5.12 Boulder
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Dec 27, 2009 - 12:29am PT
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Don't you DARE ask Minerals any more questions.........
Dude, He'll answer them.
Thanks for the link, Domngo......I don't have a TV, anymore.
Cool cameo for Smoke-a-fatty Ledge, too.
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tuolumne_tradster
Trad climber
Leading Edge of North American Plate
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Dec 27, 2009 - 12:37am PT
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Dude: who are you? his thesis adviser? is Minerals suppose to be working on his dissertation? instead he's starring in History Channel documentaries and responding to Taco queries?
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Captain...or Skully
Social climber
Top of the 5.2-5.12 Boulder
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Dec 27, 2009 - 12:40am PT
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Haha?
Whoa.
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tuolumne_tradster
Trad climber
Leading Edge of North American Plate
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Dec 27, 2009 - 01:14am PT
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I have no idea whether Minerals is a grad student working on his dissertation or not. Just a WAG.
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kaitb
climber
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Dec 27, 2009 - 10:11pm PT
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I have been fortunate to go on numerous geology hikes with Bryan (a.k.a Minerals) this past summer up in Tuolumne. I am a geology major and have learned tons of valuable information about the Tuolumne Intrusive Suite from him. I thought I would post some photos of Bryan in his element looking at rocks.
Thanks Bryan for all the great times this summer & for many more to come!
-Kait
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tuolumne_tradster
Trad climber
Leading Edge of North American Plate
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Dec 27, 2009 - 10:46pm PT
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Awesome photos Kait...thanks for posting them.
So Minerals = Bryan Law? The guy who drives the truck with the Plutonic plate and put up a route on Dozier by the same name? also featured in photo on p166 of the latest SuperTopo Tuolumne Free Climbs guide?
I finally matched up the beard...sorry I'm a little slow.
Plutonics, Cheetos & Everclear, Cheesburger & Beer, Dastardly Rascal, Slasher, Metalhead...Thanks for taking the time & effort to put up these high quality, well-protected routes.
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Captain...or Skully
Social climber
Top of the 5.2-5.12 Boulder
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Dec 28, 2009 - 12:03am PT
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That would be the Man.
Now he's a TV star, as well as a rockstar(of many facets).
Cheers, Bryan.
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Mighty Hiker
climber
Vancouver, B.C.
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Dec 28, 2009 - 12:05am PT
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Minerals, in his element. Caught momentarily without hand lens.
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tuolumne_tradster
Trad climber
Leading Edge of North American Plate
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Dec 28, 2009 - 12:29am PT
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BASE104: are you on a rig right now? Where are you drilling? I used to sit wells back in the 1980s when I worked in the oil patch.
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Jan
Mountain climber
Okinawa, Japan
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Dec 28, 2009 - 12:37am PT
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Thanks for an interesting thread. It brought back many memories of my childhood and hiking around the Colorado Rockies with my father who was a geologist.
He worked on a seismograph crew looking for oil in Texas when I was really young, and then got into mining. He should have been a teacher since my mother was right when she said a mine is just a hole in the ground that you pour money into.
Geologists tend to be romantics and gamblers in my experience, and always super interesting characters.
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tuolumne_tradster
Trad climber
Leading Edge of North American Plate
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Dec 28, 2009 - 12:43am PT
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Don't tell my Mother I'm a geologist, she thinks I'm a piano player in a brothel.
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Minerals
Social climber
The Deli
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Topic Author's Reply - Dec 28, 2009 - 01:50am PT
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Holy smokes! This thread is supposed to be about geology and rocks in Yosemite, NOT ME!!!
I really appreciate all of your nice comments! Thank you!
Anders, as far as your photo of May Lake goes, I think most of my photos are from the south shore of the lake, to the left of your photo. Most of what can be seen in your photo is Hoffmann granite (El Capitan granite), which is almost 10 million years older than the oldest unit in the Tuolumne Intrusive Suite in that area (tonalite of Glen Aulin). Yeah, there are some really neat rocks around the lake. For anyone who is interested in geology or simply looking at bizarre rocks but hasn’t been to May Lake, I highly recommend it. And, it’s only 1.2 miles to the lake. Just before you get to the final switchbacks to the lake, check out all of the fragments of metamorphic rock (xenoliths) that are caught up in Half Dome granodiorite and the tonalite of Glen Aulin.
“Dude: who are you? his thesis adviser?”
LOL!!!!!
Tradster, don’t worry about Skully; he’s just being himself. :) I haven’t been in school since 2003, but I need to go back for that piece of paper. In the mean time, I have been trying to learn what I can on my own, from the rocks and from professors that I help in the field.
As a geologist, what do you do for work now?
Yes, there is a lot of epidote on the flanks of Mt. Dana and I think you are correct in your collapsed caldera assumption.
Some work by my Reno professors on the Tioga Pass Caldera:
http://bulletin.geoscienceworld.org/cgi/content/abstract/111/11/1714
I put roof pendant in quotes because I didn’t think that everyone was familiar with the term; maybe that was a bit misleading. As you know, pretty much any older metamorphic rock that is hosted in the Sierra Nevada Batholith can be referred to as a roof pendant because it existed before magma intruded to form all of the granitic rock and is usually found near the top of the batholith.
Ugg… the photo on p. 166… (cringe)… Glad to hear that you have enjoyed the new routes, Tradster!
Cheers back at ya, Skully!!! :)
BASE104 hooked me up with one of the coolest things that a geologist could have – a copy of Annals of the Former World, personally signed by John McPhee with a personal note to me. How cool is that? Thanks again, Mark! And thanks for posting more about what you are working on! Let’s see your maps!
Kait, thanks for posting those photos – they bring back great memories! And, I can’t think of anyone who I would rather hike around and look at rocks with! ;)
Kait and altered volcanogenic metasedimentary rock, Mt. Dana
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