Discussion Topic |
|
This thread has been locked |
scuffy b
climber
Three feet higher
|
|
|
Dec 21, 2010 - 07:07pm PT
|
Just the kind of answer I was hoping for. Thanks, I'll check those
links as well.
|
|
tuolumne_tradster
Trad climber
Leading Edge of North American Plate
|
|
|
Dec 21, 2010 - 09:11pm PT
|
To add to the story that Minerals describes above see Regional Tectonic Map below from Dickinson's 2008 paper "Accretionary Mesozoic-Cenozoic expansion of the Cordilleran continental margin in California and adjacent Oregon." Geosphere 2008;4;329-353. The map is a snapshot from the Paleozoic-Mesozoic time boundary (~225 MYA) showing the Cordilleran miogeoclinal rocks (stippled orange, that includes the Zabriskie & May Lake Quartzites) offset along a regional left-lateral strike slip fault.
The line of truncation was oriented northwest-southeast at a high angle to the northeast-southwest trend of Paleozoic tectonic elements crossing Nevada (Dickinson, 2000), and is delineated in California by the eastern limit of subsequently accreted Mesozoic tectonic elements. The truncated continental margin that formed near the Paleozoic–Mesozoic time boundary became the locus for subsequent circ#m-Pacific subduction of seafloor beneath California (Hamilton,1969). The diverse post–Middle Triassic accretionary belts underlying about half the width of California accumulated sequentially against the truncated continental margin.
|
|
tuolumne_tradster
Trad climber
Leading Edge of North American Plate
|
|
|
Dec 22, 2010 - 05:25pm PT
|
Here is a chronostratigraphic chart showing the age relationships for accreted terrains in Central & Northern California, including roof pendants in the Sierrasn (Dickinson, 2008).
Here's a map showing the location of these terrains, including the May Lake Quartzite (Dickinson, 2008).
|
|
tenesmus
Trad climber
slc
|
|
|
Dec 22, 2010 - 06:26pm PT
|
I've seen checkerboards like that about 200 yards from this boulder problem. Its all red and black and chunky. fun stuff.
|
|
tenesmus
Trad climber
slc
|
|
|
Dec 22, 2010 - 06:37pm PT
|
There are loads and loads of dikes at this place. When they start to erode,the granite around them usually goes first and you are left with these cool cracks and/or features to climb. Combined with a nice creek in the spring, tall pinons and isolation, its my new favorite place.
|
|
tuolumne_tradster
Trad climber
Leading Edge of North American Plate
|
|
|
Jan 21, 2011 - 01:48am PT
|
Angular unconformity between vertical Pre-Cambrian Uncompahgre Quartzite and flat lying Devonian Elbert Sandstone, Box Canyon, Ouray, Colorado
|
|
scuffy b
climber
heading slowly NNW
|
|
|
Jan 12, 2012 - 11:25am PT
|
Happy Birthday, Steno!! What a badass the guy was.
|
|
Reilly
Mountain climber
The Other Monrovia- CA
|
|
|
Jan 12, 2012 - 11:58am PT
|
The north side of Fitzroy...
|
|
Dos XX
Trad climber
Los Angeles, CA
|
|
|
Jan 12, 2012 - 12:44pm PT
|
Very Gneiss, Reilly :-)
|
|
Bob Harrington
climber
Bishop, California
|
|
|
Jan 31, 2012 - 10:54pm PT
|
Nevadella?
|
|
Fritz
Trad climber
Choss Creek, ID
|
|
|
Jan 31, 2012 - 11:16pm PT
|
I can't identify "Bite" species, but I love to find those guys in old rock. Central Utah, a few in S. Idaho, & one I found at nearly 10,000 ft. in the Candadian Rockies.
Bites is fun!
(Trilobites)
|
|
Darwin
Trad climber
Seattle, WA
|
|
|
Jan 31, 2012 - 11:40pm PT
|
The trilobite is way cool and Reilly, thanks for that wild Fitzroy photo.
Tenesmus thanks for combining some climbing with the geology thread. Which direction from SLC does that lie?
But my real question: Specifically, are there caves in the large body of calciferous rock in the White Mountains NE of Bishop, CA? If not, is the explanation as simple as lack of water to erode/dissolve the rock? How often do large bodies of calciferous rocks exist without caves?
|
|
scuffy b
climber
heading slowly NNW
|
|
High Quality, Bob!
|
|
Minerals
Social climber
The Deli
|
|
If you dig a square hole in a playa, 10 inches deep, and then pile up the dirt into a cone, which will disappear first – the hole or the cone?
|
|
Bob Harrington
climber
Bishop, California
|
|
Looks like the hole is in the lead, but it might take a while for this race to finish. Is that Blackrock Desert?
|
|
Minerals
Social climber
The Deli
|
|
Yes, the hole won the race, and eventually, there was just a slight bump where the cone sat. Now, there is nothing. But why did the hole win the race?
South of Black Rock – Granite Springs Valley, Bluewing/Adobe Flat.
That’s quite the fossil you’ve got there! Where’s Jaybro?
|
|
scuffy b
climber
heading slowly NNW
|
|
The hole also has more opportunity to experience water-related effects.
|
|
BASE104
climber
An Oil Field
|
|
Minerals pokes his head back up! I thought we had lost you.
I need to yack with you about the work I am doing. Very exciting stuff if you are into rock mechanics and intense stratigraphy.
|
|
|
SuperTopo on the Web
|
Let us know!