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Ski
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PostFri Jun 19, 2020 2:06 pm 
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she said she found it on the beach near Seahurst in Burien. go figure.

thank you very much for your help. up.gif

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Brushbuffalo
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PostFri Jun 19, 2020 3:46 pm 
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99.99% chance it was tossed from someone's rock collection, or else from a  traintrack  bed or even road bed. Definitely not from a local outcrop......sometimes locals in some places refer to mystery rocks as meteorites!

I like the ol' guy who confidently told  me many decades ago: " There are three type  of rocks...flint rock, limey  rock, and old  field rock."
If it was only that simple! doh.gif

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Passing rocks and trees like they were standing still
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Kim Brown
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PostFri Jun 19, 2020 4:03 pm 
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Heads up; in order to assusage my guilt from interrupting their journey to the ocean trench, I liberated my rock collection by tossing them in to the Sauk River a few years ago. I tossed in rocks from the Teanaway River, the Pacific and Atlantic ocean, novelty rocks with scenes etched into them, and maybe even rocks from the city park in Etna,WY.

Someday, a geologist is going to really have an exciting day. Or a big headache. Or both.

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" I'm really happy about this! I have very strong good and horrible memories up there."  oldgranola, NWHs outdoors advocate.
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Ski
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PostFri Jun 19, 2020 5:15 pm 
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the person who found the rock wrote:
Cool.
Yes, its very strange.  I am 95% certain I picked up that rock on my beach.
If not there, then MAYBE at snoqualmie River last summer.  But it was a recent find, and I dont travel far.

(* if it was on the South Fork Snoqualmie, it would have been in the immediate vicinity of Exit 47 *)

(* and I think a good portion of my rock "collection" (such as it was) ended up dumped into the Nisqually River after I poured an "exposed aggregate" porch pad up at the cabin. most of those rocks came from Kalaloch Beach #1 *)

(* not sure what happened to the rocks I picked up while I was working on the road, but there were sure a lot of them. Wyoming and Colorado and Utah have some pretty interesting rocks. it's possible they're in a flowerbed somewhere over off East Vickery Road *)

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"I shall wear white flannel trousers, and walk upon the beach. 
I have heard the mermaids singing, each to each."
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reststep
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PostTue Jul 07, 2020 9:29 am 
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Brushbuffalo, I would be interested in hearing your comments about this rock formation. This is near Bark Shanty on the Quilcene River in Olympic National Forest.


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Malachai Constant
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PostTue Jul 07, 2020 10:28 am 
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Looks like pillow basalt from an underwater eruption. The entire west crescent of the Olympics are made of it.

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Brushbuffalo
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PostTue Jul 07, 2020 7:15 pm 
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reststep wrote:
about this rock formation. This is near Bark Shanty on the Quilcene River in Olympic National Forest.

I agree with MC. The Crescent Formation is mostly pillow basalt and is widespread on the north and east of the Olympic Peninsula such that as shown on a geologic map it forms a sort of 'basaltic horseshoe'. Pillow basalt is usually formed by underwater eruptions ( as with the Crescent formation) but can also develop as a low to moderate rate of flow of basalt flows into water from land. Rapid cooling forms a skin around  'fingers' of still-molten lava. Overlapping fingers produce a cross section of rounded blobs that reminded some geologist or other of pillows ( I like my pillow softer, thank you very much!).

The example shown in the picture doesn't show classic pillows. In fact it may be a basaltic breccia. Closer examination ( face-to- rock) would be revealing. I think this is probably a boulder (detached)  rather than bedrock (attached).

In a related bit of trivia I had the good fortune in my formative geologic year (1967) to be Tabor and Crowder's field assistant when they were first to  find pillow basalts in the NE portion of Olympic National Park, near Mt. Deception. Lucky also for me was that being in ONP this young field assistant didn't have to pack out rock specimens. bricks.gif

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reststep
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PostTue Jul 07, 2020 7:45 pm 
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Interesting, thank you. I am going to have to be on the lookout for more pillow basalt.

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gb
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PostWed Jul 08, 2020 1:08 pm 
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The bluffs along the Dosewallips road has great examples of Pillow lava. Mt. Constance itself has pretty solid rock that is essentially all Pillow basalt.
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Ski
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PostMon Jul 27, 2020 2:00 pm 
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and another mystery rock needing identifcation, if possible:

What rock is this?
What rock is this?

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"I shall wear white flannel trousers, and walk upon the beach. 
I have heard the mermaids singing, each to each."
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Brushbuffalo
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PostMon Jul 27, 2020 2:17 pm 
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Basalt.  Probably botryoidal in habit ( 'form' ). The bulbs could also be unbroken lava blisters. ( unlikely) or even miniature pillows, although pillows tend to be about  0.5 to a meter in diameter.

What is the scale and where did you get it,? From the background I'm guessing the specimen  is about the size of a football.

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Ski
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PostMon Jul 27, 2020 9:15 pm 
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the rock is about the size of an orange or a baseball - 3 inches x 4 inches (approx.)
absolutely no clue where it came from - possibly up near Snoqualmie Pass

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"I shall wear white flannel trousers, and walk upon the beach. 
I have heard the mermaids singing, each to each."
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Songs2
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PostTue Jul 28, 2020 6:05 pm 
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Brushbuffalo,

I came across an interesting photo in a trip report from the Lake Louise - Skoki Lakes (Banff) area. It is the 7th in this TR, captioned "Painted Landscape":
TR to Purple Mound
The author has some close-ups of the purple talus later in the TR.
I'd be interested to know what kind of rock is producing such a variety of color, especially that grand aubergine.
(Apologies; I don't know how to link the photo.)
Thanks!
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Brushbuffalo
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PostWed Jul 29, 2020 8:43 am 
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Usually purple is due to high iron content. Not uncommon in siltsone or  sometimes sandstone of deep marine origin.

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Ski
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PostWed Jul 29, 2020 8:59 am 
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Brushbuffalo - thank you again very much for your help. up.gif

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"I shall wear white flannel trousers, and walk upon the beach. 
I have heard the mermaids singing, each to each."
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