2008
Field Trip
Part 2 the Point of Rocks on US 95 just southeast of the Crystal/Pahrump turnoff
On the way to the location where the Point of Rocks limestones will be examined, there were some views back to the Striped Hills from the south on US 95:
There was also a good view of Skull Mountain (see the two eyes and nose in black on its left face? that's what it was named for):
The first stop was at the Pahrump/Crystal road--US 95 junction to again see the Spring Mountains and imagine it coming northwestward at us and at the same time moving more to the west at its northern extent, creating that bulldozer blade effect (what actually happened, as explained at the previous stop, was that where we awere standing moved toward the Spring Range, to the southeast along the Las Vegas Valey Shear Zone, but if we had been standing here during that movement it would have appered that the Spring Range was moving toward us. A scientific description of the "flower" at the Point of Rocks is given in this abstract by Damian Piaschyk and Tom Anderson available on the internet (click on this sentence to read it):
Next we imagined ourselves in the place of the limestones across the road as this blade dug under them and propelled them up and build up pressure that ended up pushed them forward toward the Spring Range:
Just a bit further north the rock lies horizontally but has been pushed up and forward:
Next we drove 'south' on US 95 for just a few miles until we came to a very broken up section of limestone. The way we were asked to imagine this section was to picture it compressed by the forward motion of the LVVSZ (see previous page) and its bulldozer blade, and being squeezed together because the land mass behind it did not give. The result looks like a flower in two dimensions, squeezed at the stem and a petal being pushed up in both directions and falling away from the stem. If that is the right way to picture what happened to this rock, this photo would be the "petal" that fell toward the north:
According to our geologist guide, in the center of this formation there is a 1,000-foot thick section of limestone that is now only a few hundred feet thick. As this material got squeezed that layer fractured and became spread out over a larger area, allowing the rock above it to move away from the source of the pressure more easily.
And The "petal" to the south was cut to allow US-95 to slide by, and it shows the kind of phenomenon in miniature that we were told about on the opposite side. Here some sizable chunks were pushed around making dust of a layer along which it moved:
A similar bit of ground rock (vertical here and looking a bit brownish) shows up in this next photo as well:
What does this wall look like without the road-cut? Quite rough and broken as well:
So the road-cut gives us a glimpse of the innards of this broken up formerly horizontal series of limestone beds:
Never discount the ability of life to find itself a home, these beauties grow along US 95 at the base of this stack of broken rock:
Now we take up US 95 again and go south until we approach the place where a road heads west to a village called Cold Creek. The road lies between the two state prisons located just south of Indian Springs, Nevada.
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