Tuesday, May 28, 2013

Road Song: Stories We Could Tell

This song always reminds me of "the life" -- that is, the life of an exploration geologist. You may have to click through to YouTube to listen to this original version, which is the one I know best.

John Sebastian: Stories We Could Tell (lyrics)
Album: Tarzana Kid, 1974
John Sebastian website (has auto-playing music turned on)

Here's another version, with the pixelated pictures evoking the kind of traveling I'm thinking of when I hear the music. You may still have to listen to it on YouTube.

Jimmy Buffett: Stories We Could Tell
Album: A-1-A, 1974
Jimmy Buffett website
So if you're on the road a-trackin' down your every night
And singin' for a livin' neath the brightly colored lights
And if you ever wonder why you ride the carousel
You did it for the stories you could tell
(emphasis mine)

Friday, May 24, 2013

Things You Find in the Field: Fauna on and near Rocks...OR...on and amongst the Flora

Blue belly lizard near some foliated andesite (this is the Great Basin Fence Lizard, or Sceloporus occidentalis longipes).
(click any photo to enlarge)
The lizard was rather skittish, and I couldn't get very close.
Read more about blue bellies in an earlier post.
A lizard of unknown denomination running over a lichen-covered outcrop.
A very small gray and white bird perched on a gray rock
atop an iron-stained outcrop (upper right).
Two shining leaf chafers or "Little Bears."
AKA Paracotalpa granicollis, a kind of scarab beetle.
And finally, a meadowlark atop a sagebrush.
I hear meadowlarks often, but am not always quite so lucky as to see them. This time, I was crossing a muddy little stream by a meadow, on my way to take the long way home (I didn't know it was *such* a long way, but oh well) when I heard this one singing.

Tuesday, May 21, 2013

Fault Breccia on Slickenside Ridge

Up above our last hiking stop on Slickenside Ridge, MOH and I came across this wonderful exposure of a breccia (hiking stick for scale).
Here's a closer view, showing massive and drusy quartz cementing  the breccia and filling vugs left in the rock.
This is a type of fault breccia — though I was so into my admiration of the breccia that didn't think to look for the fault  — and you can see hints of slightly oblique slickenlines on the smooth upper surface in the first photo.

In fact, it just occurred to me to show you what I mean, so here are two photos of that upper surface, one without drawings, one with.
Planar fault surface from the 1st photo, enlarged.
Same photo with some lines drawn in.
The possible slickenlines in the upper left are the ones I noticed first; the second possible slickenline direction shown in the lower right is vaguer, might be my imagination. More field work required!
A zoomed view of the "best" part of the breccia.
Looking northwest toward Winnemucca Mountain (hidden from view by my choice of framing).
Now I've walked back over to the spot where I left you in the last post, looking down Water Canyon toward the northwest. Just above the bright reddish orange dike rock on the right side of the photo, on the hill across the canyon, you can see the lower part of a rock wall first mentioned in this early post about the dikes.
Looking back down the hill and across the canyon.
And so now, as we turn to head back down the hill, we might think about investigating the rock wall on the far hill, the one we sometimes call "Dike Hill."

Sunday, May 19, 2013

Views from the Field: Humboldt River Basin

I've been out in the field on a fairly routine basis recently, taking pictures mostly of rocks and my hammer (for scale). Occasionally I take a photo or two looking off into the distance, or of other non-work items (like lizards) that I come across.

This photo looks more or less southwest across the southern part of the Humboldt Range, with the green, irrigated fields of the lower Humboldt River basin a few miles below Rye Patch Reservoir and just above the Humboldt Sink in view off in the distance. Location of the Humboldt Sink linked below.

The interesting shape of the juniper wood is what really caught my attention!

Tuesday, May 14, 2013

Slickenside Ridge #3

Coming up Slickenside Ridge past the last little slickenside, we came upon this whopper.

It's hard to tell from this photo, but fractured, brecciated, and slickensided dike rock on the far side of the fault plane is juxtaposed against more dike rock, which is what I'm standing on to take the photo. The fault is dipping more or less to the east, and the slickenlines are almost straight downdip (slightly oblique).
A closter view of the lower part of the slickenside.
An even closer view of the lower part of the slickensided surface.
Using the the direction of some of the steps in the slickensides in these photos, I deduce that the motion is normal, with the east or outcrop side down with respect to the west side. This direction would be expected in a Basin-and-Range setting, but the observed steps don't face uniformly upward, so I can't be sure of my interpretation without further work (offset of beds across the fault would be ideal).

We also noticed a nearby cross-cutting fault of minor displacement running about east-west, offsetting this fault and the faulted dike-dike contact by a few feet. Apparent offset across this cross fault was south side to the east (the fault was poorly exposed and dip direction wasn't obvious).
View of "Dike Hill" across Water Canyon.
We made it up to the notable first juniper tree, and stopped to look across the canyon at the dikes, which were blogged about here, here, and here.
We viewed the hill again a little higher up, from this little shadow created by an outcrop of  quartzite.

We then hiked up to our final outcrop and this view of Winnemucca Mountain (on the left beyond the town of Winnemucca) and the Santa Rosa Range (the bluish mountains on the far right).

Our hike wasn't over, though...

Thursday, May 9, 2013

Slickenside Ridge #2

A small set of slickensides, with slickenside float above, on Slickenside Ridge above the last locality, this time in quartzite only.
Looking uphill toward more dike rock, green grass, and blue sky. Quartzite is deep in shadow on the right.
What else will we find?

Monday, May 6, 2013

Slickenside Ridge #1

Slickenside Ridge is our personal name for a narrow ridge south of Water Canyon, south of an area that MOH and I sometimes call "Dike Hill." Here we are looking across toward Dike Hill, with a face of slickensided, slickenlined quartzite in deep shadow on the right. The contacts between the quartzite and the porphyry dikes, discussed most recently here, seem to be faulted almost everywhere on the lower part of Slickenside Ridge.
Slickensides on quartzite.
Slickenside with slickenlines; hand for scale.
I've reached over to place my hand in the photo, while trying to maintain my camera at verticality.
Slickenside and slickenlines; no hand for scale.
Now I've tried to maintiain verticality without having my hand in the photo. The outcrop was difficult to photograph because of rocks. The first photo not in shadow (second photo above) shows a less oblique, nearly downdip apparent orientation of the slickenlines than the photo above where I was trying hard to get a photo of the true orientation. Not really sure which photo reflects reality better, but I do think the slickenlines were somewhat oblique. (Too bad I don't usually hike with my Brunton!)
Gratuitous shot of spring wildflower: a buttercup, possibly this buttercup, also seen here, though they all look about the same to me.

Thursday, May 2, 2013

Things You Find in the Field: Pyramidal Objects #3

A few years back, while out taking a set of roads that makes a large loop starting from Highway 50 at either Garnet Hill or Ely, going either northeast or north and then going west, then heading north and west some more, and then running back south to Highway 50 at the Thirty Mile Road junction, MOH and I ran across this wooden pyramid at Summit Springs near Piscevich Summit (MSRMaps location and also see the Google Maps Location at the end of this post).
A closer view of the wooden pyramid.
Even closer.
I really don't know what this type of structure is used for, but went inside to take a look.
Inside view: a metal pipe runs up one wall and out the top.
Another inside view.
Possibly this small structure was used as a smoke house? (And although I don't see a lot of coating of the walls by creosote, some planks look darkened.)
Inside looking out toward a tree near the spring.
A second inside-looking-out view, this time past tree No. 2 toward the broad curve into Bothwick Creek canyon, which runs off to the north (right).