Wednesday, September 30, 2015

Finding a Thesis: Klondyke District

Some of you might remember, back in the distant past of this blog, a time when I was on my seemingly endless thesis-hunting journey, and I was just about to leave Belmont, the silver mining district and small town in central Nevada:
"I finished up looking around the old dumps, headed back over the pass, coasted downhill through Manhattan and back to Highway 8A, and then I turned left, to cruise south toward Route 6. My route would take me through Tonopah, past the Divide district, into the Palmetto Mountains, and on to Silver Peak."
I thought that Belmont had looked rather interesting, perhaps the most interesting of the areas I had seen so far, its dumps covered with quartz vein material containing as-yet unidentified ore minerals (unidentified to me, that is), but I nevertheless moved on toward my next target, the Klondyke mining district (AKA Klondike district, AKA Southern Klondyke district), an historic silver producing area not far south of Tonopah.

When I drove into the Klondyke district back in 1976, the only existing maps for the area consisted of the 1962 Goldfield 2° sheet (an AMS sheet) and the 1952 Mud Lake 15' map (in this case, also an AMS sheet; see more about these maps at an earlier blog post in this series). Both maps show U.S. Highway 95 on an old alignment that took it just west of the Klondyke area. These were the days before 95 was rerouted around Hasbrouk Peak in the 1970s (the route change appears to have taken place sometime between the issuance of the 1976-77 and 1978-79 Nevada road maps), and so the maps showed the Highway 95 I knew at the time. And, continuing with the theme of my thesis hunt taking me to, through, and by areas I would come to know more about in the future, it turns out that Hasbrouk Peak is essentially a small hill of gold, one that Former Mining Company would come to drill in the mid or late 1980s.

The 2° sheet shows very little detail; the 15’ map shows a little more:
Goldfield 2° sheet from the USGS via MSRMaps. The hills in the north-central part of the map comprise part of the Tonopah-Divide district, with Tonopah just off the map to the north. The Klondyke district sits in the center of the map in an area marked "Numerous mines."
A portion of the Mud Lake, NV 15' map, via the USGS Map Locator & Downloader. The hills of interest are nearly dead center. Only a few of many prospect pits, cuts, trenches, adits, and shafts are shown.
These maps make it look like it should be fairly easy to get to the low hills of the Klondyke district, but because of a highway right-of-way fence that blocked most dirt roads shown on the old maps, I ended up driving back and forth several times before finding the right road. I’m not really sure how long it took me to find the right road, nor do I know now which road finally took me through the fence, but I do know that I didn't get out of my ’72 Opel, grab the bolt cutters that I didn’t know to carry with me back then, and cut the fence, so I must have found a way around the fence. The old maps offer me no clues, nor do easily accessible air photos.

I did finally arrive at the white, pale orange, and brownish low hills of the area, hills underlain by Paleozoic carbonate and siliclastic units intruded by granite and alaskite.
Vertical beds!
The oldtimers had found enriched silver in quartz veins cutting the sedimentary formations, at least partly below a thrust fault. Chlorargyrite, a secondary silver mineral, was reported to be the dominant ore mineral, something that would have been key to my advisor, a tall lanky man whose interests ran to silver prospecting, silver discoveries, drilling silver properties, and secondary silver minerals (all things silver).

I banged on a few rocks, shook my head with wonder a few times, looked around the dumps for old bottles and such, and went back to the paved highway.

I revisited the Klondyke area a few years back while on my way into western Esmeralda County to check out a land sale. I got onto the old highway easily, and I nearly immediately found a decent road heading into the low hills. The old right-of-way fence was gone (or moved to the new alignment), and the turn into the area was quite obvious.
Looking north along old U.S. 95 toward Tonopah.
Looking south down old U.S. 95 toward Goldfield.
This turnoff to the low hills of the Klondyke district is obvious, and the fence has been removed.
A lizard!
The partly marbleized carbonates suggest a complex history of deformation and veining.
A piece of jasperoid shows a reddish brown color that I now think of as fairly typical of base metal or silver – base metal districts.
Old junk and mine workings and dumps. There are two shadowed cuts on a low hill in the distance to the left of the 55 gal drum, and a small cut in the dark area to the left of that.
This is the small cut in the dark area mentioned above. Ooh, what’s that I spot just below the bush on the right?
A sample tag. Someone has been here!
Anyone want to claim this sample number?
I headed back to the highway, realizing that I knew a lot more than I did on my first visit to the area, when I really wan't that sure of what I was looking at. I checked out the old alignments once again, and found this particular section that had gone entirely to dirt.
The old alignment joins the current alignment just beyond the first hill, and goes off toward Goldfield.
I then rejoined the active alignment of U.S. 95 and steered my way south toward Goldfield and beyond to the turnoff to the Palmetto Mountains.

Previous Posts in this Series:
Thesis: Finding an Area
Finding a Thesis: Battle Mountain to Austin to Gabbs
Finding a Thesis: Pole Line Road
Finding a Thesis: Pole Line to Belmont

Tuesday, September 8, 2015

Way Too Much Smoke: Volcanoes (and Rivers and Ridges) in the Pacific Northwest

Mt. Jefferson
There I was minding my own business while flying north from RNO to SEA (that is to say, I was reading a thick book and trying to ignore a seatmate while crammed against the window near the rear of a Q400), when I looked out (to the east) and spotted the peak of an Oregon volcano sticking out through what I first thought was a low, thick cloud cover. I grabbed a few quick shots through a badly spotted and smeared window, while rapidly revising my reckoning about the cloud bank: no clouds, just a very dense blanket of smoke.

Whereas I first estimated I was somewhere over central Oregon south of Sisters or Bend, it soon became apparent that I was probably a little farther north than I thought — and it turns out I was between Sisters and Portland looking at Mt. Jefferson (first photo).
Mt. Hood
The photo above shows Mt. Hood barely sticking up above the dense smoke bank. Hard to say exactly, but it looks like the smoke is about 10,000 feet thick! Hood's peak sits at an elevation of 11,240 feet, and its south shoulder sits at somewhat above 10,400 or 10,600 feet (depending on what part of the shoulder we're actually looking at); the Portland outliers of Troutdale and Springdale in the foreground have elevations of about 100 feet and 300 feet, respectively. As a geographical point of interest, the larger, streamlined island on the north side of the wide Columbia River is Reed Island. The river beyond the island fades gradually and then disappears abruptly in the distance.
Mt. St. Helens
My first view of Mt. St. Helens was of what I call the back side (the south side). It's clearly not an ordinary Cascade volcano by today's standard of nice, symmetrical peaks, although several Cascade volcanoes are known to have created lateral blasts like the one St. Helens produced in May, 1980 — and maybe all or most have done something like that sometime in the past.
Mt. St. Helens
This second shot of Mt. St. Helens (above) shows the South Fork of the Toutle River in the foreground and Spirit Lake in the background.
Mt. St. Helens and Mt. Adams
Mt. Adams can be seen in the distance, barely sticking up above the smoke, even though it reaches an elevation of 12,277 feet!
North Fork Toutle River
This view of the Toutle River (Google Maps location) shows an area just above the Toutle River Sediment Retention Structure. The berg of St. Helens sits across from a green, tear-dropped-shaped "island" that is marked as hill 11227 on some topographic maps (e.g. this one at the USGS TNM 2.0 Viewer).
Smoke amid the low hills between Mt. St. Helens and Mt. Ranier
One last look at Mt. St. Helens
Mt. Ranier
Mt. Ranier, the tallest Cascade volcano at an elevation of 14,410 feet, rises above the smoke more than any of the others. The clouds obscuring its peak make it appear to be erupting (it wasn't).
A last view of Mt. Ranier, seen as the airplane descended toward SeaTac.
Smoky wisps interfinger with some low hills north of the airport after take off several hours later.
Photos taken 26August15 between 10:13am and 4:59 pm, PDT.

A Bit More about Mt. St. Helens:
Where in the West: Mt. St. Helens — LFD
Mt. St. Helens Field Trip — LFD
It's the 35th Anniversary of the Big Ba-Boom: Mount St. Helens and the May 18th Eruption — Rosetta Stones
Why Have Volcanoes in the Cascades Been So Quiet Lately?  — Eruptions