Sierra Nevada / Cascade Mtn. Boundary ???

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aldude

climber
Monument Manor
Topic Author's Original Post - Apr 28, 2008 - 05:17pm PT
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Geography question : Where does the Sierra end and the Cascades begin? Some say the Sierra Buttes (above) in Sierra county are the northern terminus of the Sierra Nevada - others assign the boundary in Plumas county near the North Fork of the Feather River ( Grizzly Dome ) on highway 70. The Buttes are metamorphic - Grizzly Dome - granitic. I'm goin with Plumas Co. Thoughts?
Mighty Hiker

Social climber
Vancouver, B.C.
Apr 28, 2008 - 05:25pm PT
Wikipedia says the U.S. Sierra Nevada mountains (the original Sierra Nevada are in Spain) ends at Fredonyer Pass, which seems to be somewhere near Mount Lassen. (?) http://en.wikipedia.org/wiki/Sierra_Nevada_(U.S.);

The Cascade Range apparently goes from Mt. Shasta right through to the Fraser River, which somewhat surprises me - I'd somehow always thought that they were just in Washington and the south bit of B.C. http://en.wikipedia.org/wiki/Cascade_Range

The Cascades are named for cascades on the Columbia River where it breaks through the range, although maybe they're now submerged behind dams.
aldude

climber
Monument Manor
Topic Author's Reply - Apr 28, 2008 - 05:43pm PT
Ok then - Lassen County it is.

Here's a pic of Grizzly Dome - Plumas County.

BTW - the most popular climbing area in the county ! ? !

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Spencer Adkisson

Trad climber
Reno, NV
Apr 28, 2008 - 05:53pm PT
Mighty Hi,
Wikipedia is not the most reliable source for information in the world. I do alot of rockhounding, and grew up in Chico, so those hills are my stomping grounds. I would call the Feather River the dividing line between the Sierra Nevada and the Cascade Range. The rock type is granitic with contact metamorphism on the south side of the river, and quickly changes into a characteristic volcanic landscape with Mt.Lassen and the ancestral remnants of Mt.Tehema dominating the landscape. Bald Rock Dome and Big Bald Rock lie somewhat South, Southeast of the area of the Feather that I am considering the "line" (Grizzly Dome Tunnel/Elephant Butte). But you can't really draw a line and say it's one thing here, and another thing over there, b ecause there is probably about twenty miles or more of transition zone where the two regions overlap and mix.

You are probably thinking of the North Cascades in Washington, but the Cascades run the entire length from the Feather River to the Frazier River.

Does that help?
Mighty Hiker

Social climber
Vancouver, B.C.
Apr 28, 2008 - 06:00pm PT
I've driven up and down Interstate 5 many times, and the mountains seem awfully continuous to me - I'm not sure myself how or why they're divided into different ranges. There's a section from Mount Saint Helens to Mount Hood that isn't all that high, and other sections in southern Oregon and again south of Mount Shasta that are fairly low. So if the definition of a range is a contiguous group of mountains, more or less along a crest, it's not readily apparent why the entire distance from northern California to southern B.C. should be considered one range.

The dividing line between B.C.'s Coast Range and the Cascades is the Fraser River - but other large rivers divide the Coast Range. The range is still called the Coast Range, but those subdivisions sometimes have their own names, e.g. the Waddington Range.

Perhaps there's a geographer or geologist who could chime in and educate us about mountain nomenclature?

Yes, I'm well aware of the limitations of wikipedia, and the net generally, for reliable information.
Spencer Adkisson

Trad climber
Reno, NV
Apr 28, 2008 - 07:13pm PT
Ding-o,
What is your take on the Sutter Buttes? (Besides being PRIME wild pig hunting grounds)
rhyang

Ice climber
SJC
Apr 28, 2008 - 07:13pm PT
Lassen is also in the Cascades, according to the National Park Service :

"On May 22, 1915, an explosive eruption at Lassen Peak, the southernmost active volcano in the Cascade Range [...]"
Spencer Adkisson

Trad climber
Reno, NV
Apr 28, 2008 - 07:15pm PT
Yes, definitely a Cascade Volcano.
Jaybro

Social climber
The West
Apr 28, 2008 - 07:16pm PT
I'd almost go with the Feather river dividing point, but the Sierra Buttes, always look cascade-ish to me.
nita

climber
chica from chico, I don't claim to be a daisy
Apr 28, 2008 - 07:41pm PT
Nita's man, Andy, here (she asked that I chime in as I have a heavy burden of knowledge that I need to unload from time to time)

As a Chicoan for the last 20 something years and a natural history buff naked I can only tell you what I learned from a geologically fixated friend; #1 You can't judge a book by it's cover; translation; More recent geologic events may obscure the underlaying foundation of rock (ie. Mammoth).
#2 In Chico's case (as I am told) around Lake Almanor near the Hwy 89/36 jucnction the Sierran related granite takes a dive underground. The Keddie Mts nearby are the most above ground northern remnant.
#3 Feel free to prove me wrong. I can take it.

Andy ps Kleinfelter's airplane party in Bishop was a hoot!
Jaybro

Social climber
The West
Apr 28, 2008 - 08:01pm PT
If you wade into the water of Sardine lake and listen closely, you hear Jack Nicholson ordering Rye (wheat?) toast. Cascades, I say!

It don't all gotta be the same age/consistency. think of the Minarets.

-Maybe the Cascades are a subset of the S.Buttes?
tom woods

Gym climber
Bishop, CA
Apr 28, 2008 - 08:16pm PT
How 'bout the Trinity Alps. I always heard that the granite there was the same pluton? as the sierra. The're pretty far north in California.

Tom
Mighty Hiker

Social climber
Vancouver, B.C.
Apr 28, 2008 - 08:22pm PT
No doubt the creation "scientists" have an explanation for it all.
Jaybro

Social climber
The West
Apr 28, 2008 - 08:24pm PT
I always avoid orgiastic antlers...
ontheedgeandscaredtodeath

Trad climber
San Francisco, Ca
Apr 28, 2008 - 08:27pm PT
Yeah, where do the alps and the marble mountains fit in? Are they outliers or part of one of the major ranges? The Marbles don't look the alps, cascades or sierra.
Ed Bannister

Mountain climber
Riverside, CA
Apr 28, 2008 - 08:28pm PT
If you think of the sierra, as the uplifted batholith of that special recipie slow cooled granite we love, Andy, Nita's man, is correct.
rhyang

Ice climber
SJC
Apr 28, 2008 - 09:23pm PT
The Trinity Alps and Marbles are part of the Klamaths.
aldude

climber
Monument Manor
Topic Author's Reply - Apr 28, 2008 - 09:25pm PT
[/url]

" Cascade Buttes " ........hmmmm, doesn't sound rite.

Was skiing up there last week and lo & behold saw a vien of what I thought to be gold bearing quartz !! With the price of gold being what it is , I'll be up there with the bulldog and and some boulder-buster powder this summer. Maybe bag some more routes as well - BTW , any of yooze guys/gals ever climb there? I'm compiling a list of climbs in the area - please post up ***
tom woods

Gym climber
Bishop, CA
Apr 28, 2008 - 09:26pm PT
The trinities are very different from the marbles, but in many places simalar to the sierra. Geography and Geology, I guess are two different forces working on our conversation.

Tom
nature

climber
Santa Fe, NM
Apr 28, 2008 - 09:53pm PT
Lassen is part of the Cascade range.

I have a Friends of the Pleistocene field trip guide from about 10 years back where we went out and explored the Cascade/Sierra boundary. If I feel so inspired I might bust it out. Only problem is the damn thing is about 600 pages long. Trip Leader got GRILLED for the monster :-).

(not that I remember much from my Daze at Humboldt but I did do graduate work in Geology - Papajoto did as well and he confirms on Lassen).

Edit: Lassen is the southern extent of Cascadia extrusive volcanism. Around the Lake Almanor area any basalt north of there is Tertiary and part of the Cascade complex. Basalts south or there are Cenezoic (or older) and part of either the Sierra Nevada or are Sierra Nevada roof pendants (country rock that existed >40Ma [before intrusion]). If you run into granitic like rock (less than 10% of Sierra Nevada rock is a true Granite - mostly it's grano-diorite) you are in Sierra Nevada Terrane.

Double Edit: I can't believe I just pulled that sh#t out of my head. I studied dirt not igneous petrology. Some times mud sticks :-)

Triple Edit: If I recall correctly there is reason the Trinities are similar to the Sierra. They were once a part of the Sierra but right later sheering associated with onset of the San Andrea's transported them north. Crustal banding and intrusion of the Cascadia volcanics now sammich that terrane between the two (gotta knock out some cob webs on this one).
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