Tuesday, January 19, 2010

The Eureka Quartzite on Squaw Peak

Yes, it's the Eureka Quartzite again, this time on a 2416 m hill (7926 ft) known as Squaw Peak, located in White Pine County, Nevada, just above the small town of Ely.
Squaw Peak is the hill in the center of the photo, just a bit to the left of where Highway 50 is pointing before it turns to the right [MSRMaps map of Squaw Peak]. Highway 50 points almost straight at the Ordovician Eureka Quartzite, which is the second ledge below the cliffy top of Squaw Peak. The upper ledge is mapped as the Silurian Laketown Dolomite.
Here's another view of the Eureka Quartzite below Squaw Peak, this time in winter. Again, the quartzite is the lower, brownish cliff.
And again, looking to the northwest - this time the Eureka quarztite is cream colored and really stands out.
If you ever happen to stay in the Bristlecone Motel, near the junction of Route 6 east, Highway 50 east, and Highway 93 south with Highway 93 north, you'll have this view of the bright and shiny Eureka Quartzite in the morning. The quartzite thins to the north; I don't know if that's from stratigraphic or tectonic thinning or some combination of the two. I do know that the quartzite is moderately to strongly brecciated and cut by numerous fractures and faults showing nice slickenlines.
When coming in to town from the west (or the east, for that matter), you can easily pull over on the south side of the road - the main street, Aultman Street, is Highway 50 through the main part of Ely - and stop at the county park [a similar view with Google Maps].
Look to the north and there you have it: the Eureka Quartzite. It's the cliffy ledge of light-colored rock on the lower slope, below and to the right of the radio towers on Squaw Peak.
To get to the outcrop, take 7th street north across the railroad tracks and immediately turn right on a dirt road, Visa (Vista?) Grande Drive, which may or may not be marked. From that road, you can walk up onto the alluvial fan, and from there you can clamber up the steep and rocky talus slope to this exposure of the Eureka Quartzite. It's a white to cream-colored, shiny, hard, orthoquartzite. Some of the best of my current photos of the quartzite can be seen in this post about nesting ravens. After the snow goes off the mountain, I'll climb up and bring back some nice hand samples.

Some References:Brokaw, A.L., 1967, Geologic map and sections of the Ely quadrangle, White Pine County, Nevada: U.S. Geological Survey Map GQ-697, scale 1:24,000.

Brokaw, A.L., Bauer, H.L., and Breitrick, R.A., 1973, Geologic map of the Ruth quadrangle, White Pine County, Nevada: U.S. Geological Survey Map GQ-1085, scale 1:24,000.

See this post for links to many previous Eureka Quartzite posts and additional references.


Gaelyn said...

That Quartzsite sure stand out prominently on the peak. I especially like the sunrise shot.

Diane AZ said...

Interesting to see the different views of the Eureka Quartzite. Like Gaelyn, my favorite shot is the morning one. I like your nesting ravens post too.

Silver Fox said...

Now you know where to find it!

Susan Higgins said...

I love Geology! Your pictures and descriptions are great for a rock enthusiast.

Silver Fox said...

Susan, the quartzite is a long way from your location, so I guess these photos will have to suffice. Thanks for reading! :)