Post by mohs on Sept 10, 2021 14:33:33 GMT -5
That is what I'm trying to establish now mohs
I believe the buttes themselves are ancient granite with two layers of landslide coatings.
The southwest half of south Mountain is ~1.5 billion year old granite that was metamorphosed to gneiss.
The northeastern half is 25 million year old granite. in the middle is 22 million year old granite that caused the northeast corner to brecciate. Something later caused the outer layer to brecciate again making two layers, the outer layer finer than the inner.
That would provide the two slides.
The first slide was MOSTLY rhyolite.
The second slide was MOSTLY granite.
So far I haven't found of there being any rhyolite on South Mountain. Perhaps most of it was removed with the first slide, and the rest with the second?
Now, does the granite in the Barnes Butte Breccia match the granite from South Mountain?
I agree with the clastz originating from the
South Mountain Metamorphic Kinematic Complex …mostly
Where my confusion arises from is the process of the dates.
South Mountain up-thrusted & shredded the clasticz.
The thing is:
what fault block then upthrusted
& created the Papago's?
I have difficult time understanding
that clastz and the formation of the Pagago’s
in one swell swoop.
the clasticz came first.
Then the Buttes formed a long times after,,,,
just thinking out loud
Post by mohs on Sept 13, 2021 15:02:44 GMT -5
right on 1dave
not sure I ever saw that pictorial before
only vaguely familiar w/ the
Rocking w/ Rock website.
Thanks for posting!
was real informative in this here discussion
Hope he’s hounding healthily across the pond !
Now I just got back from quick inspection of Tempe Butte
have stopped a couple time this week
Still to hot to do anything serious
Besides a small trailsting
But I took a camera photo
have some thoughts on its development
will be posting my initial thoughts
so stay tuned
till then ...
Post by mohs on Sept 14, 2021 14:30:28 GMT -5
Here another conundrum
This is Tempe Butte
A quick shot from my Phone
After I fiddle and sweated figuring it out
Plus I had a hard shell taco
At Master Taco
But that another story…mostly
Tempe Butte is located at 50th street & University
That basically puts it in line 3 miles south off the Papago's
Not that much of a distance
The surrounding ground is fairly flat.
The grounds around Papago's are quite elevated
A humongous pediment of meta- granitoid.
Yet the upper halves of the Tempe Buttes
Are formed from what I consider to be metamorphic tuffacious rhyolite
Billions and billions of tons ejected from some way past distant super volcano !
From the Superstitions Mountains, mostly ?
Maybe, even from Utah
of even Yellowstone.
Anyway the pyroclastic flow was immense and that flow got buried and pressurized.
Some time later—a violent thrust uplifted this tuff
w/ a humongous granite pediment beneath. !
that the Tempe Buttes differs so much from their metamorphosed neighbors the Papago’s
is of note
They are so close by-- to be so different!
The first thing you notice is the absence of the red bed
Well...not prepared to go to far into this analysis
So till then….
I do have a thought
Which may account for the anomaly
of the Tempe Buttes and Papago Buttes
being so different in structure /
Especially the absence of the red beds
Tempe Buttes are on the south side of the Salt River !
The Papago’s on the north
It is hypothesized that the red beds originated from the north.
Is it possible that the Salt River stopped the southerly flow?
Any thoughts on this is 1dave
Post by mohs on Sept 15, 2021 10:06:17 GMT -5
Right on 1dave
Ya know we need to be wary of the Faustian bargain
Besides these geological concerns are deep
and these Buttes are deeper than known
At least my one corundum is answered!
What came first?
The Salt River or the CamelHead Formation ?
red bed flows were halted.
The Salt River existed
Hence--- the Salt River was there before the Buttes formation
Post by mohs on Sept 15, 2021 15:20:21 GMT -5
another anomaly I noticeed
This is the east side of the Tempe Butte
In this example that slope is peppered
w/ easily recognizable clasticz!
Granite and meta-rhyolite variety in brownish soiled matrix,
lacking that red beds of the Papa's
The west side of those Buttes seems to be totally different!
That slope is covered in a thick thick slick covering of what appears
to be frozen molten metamorphic pyroclastic rhyolite
And no easily seen clasticz !
Not sure how that occurs?
Butte I’ll come up with some far fetched idea, mostly
But ya know Dave your wise saying holds true in my Butte analysis
The theory may be wrong, . . . . but It's MINE!
Post by rockpickerforever on Sept 15, 2021 20:08:27 GMT -5
A few more AZ Red Rock Clasts for mohs
We've done a lot of traveling in AZ, we love the landscapes, and the rocks.
These first several photos were taken to the east of Alamo Lake. Red rocks, no lava or basalt.
One of my favorite pics from this trip
Mountains to the north side of lake.
Gash in center of mountain in above photo as seen through telephoto lens. There were some people mining for gold in this area.
This area was littered with some nice chalcedony roses.
Holes/shallow caves in rock cliff.
Bob for scale
More rocks and shrubbery. The rocks almost look like they are stacked in a wall.
This is much further into AZ. Swansea is a Ghost town in La Paz County in the U.S. state of Arizona.
The town is associated with a large, but ultimately unsuccessful, copper mining operation.
An arch seen on the way driving in.
Another shot of it.
I've got photos taken of the town, but since this thread is about AZ geology, I didn't post them here.
To learn more about Swansea, you can visit this web site: Swansea 2.0
Swansea was a past producer of Copper, silver, gold, iron.
Post by mohs on Sept 15, 2021 20:20:32 GMT -5
o that Buttifull Jean !
you probably know that part of Az a lot better than I
I'm ashamed to say I never been to Alamo Lake !
I plan on correcting that soon
drove by it w/ Rockoonz
on return from Washington St
brother would go fishing there decades ago
legendary trips ha
so its on my holy bucket list
I'm fooling w/ hotspot and internet provider crap
butte I';; be back
thanks for posting !!!
Post by mohs on Nov 1, 2021 16:42:27 GMT -5
So I took hike to inspect
Both sides have mica inclusions
Best I could tell
That fine grain side is really compacted
so hard- to determine
What would be the implication of mica free?
Post by mohs on Nov 2, 2021 10:44:11 GMT -5
right on Dave
maybe that one side is quartzite?
maybe all of it
hadn't consider that
it appeared to be granite
I may be wrong
just like the desert vanish
the underlying stone is quartzite
that contact zone is distinct
probably a scientific analysis
Age, type, location ectal...
Post by mohs on Nov 2, 2021 18:36:39 GMT -5
the Most important this is To Protect That Butte !
at all cost
right on 1dave
working on getting clearance
wild stories around here
about underground complexes
windows in the buttes
it was ww2 training facility
and POW camp
lots of secrets got traded...