Road Song: Copperhead Road

Steve Earle: Copperhead Road (lyrics)
Album: Copperhead Road, 1998

This is a classic road song with "road" right there in the title, courtesy once again of MOH. I can't say that I have any particular memories around this song, but the music video is quite evocative with respect to the eastern backwoods (which I remember well from my years back there), Vietnam, and what might be protecting the younger John Lee Pettimore III's current crop, which isn't moonshine.

Where it All Began, Part II

Continued from Where It All Began, which ended:

That, anyway, is one way to make a geologist, although I’m sure there are also other ways. One thing that geologists are sure of is the existence and viability of other ways — this idea is technically referred to as “multiple working hypotheses,” and it’s sometimes stated as, “if ten geologists mapped the same area, you’d end up with at least ten different maps."

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Half Dome

The western U.S. — from the subduction-bounded and transform-faulted Pacific coast to the uplifted and locally hog-backed eastern border of the Rocky Mountains — is a tectonically active region. This activity is revealed in the Mesozoic intrusion, cooling, and crystallization of the great Sierra Nevada batholith (65 to 210 million years ago), in the Holocene to Miocene faulting of the San Andreas fault system (0 to 35 million years ago), and in the Pleistocene to Pliocene uplift of the Sierra Nevada Mountains as a block (1 to 3 million years ago especially, with some uplift still continuing). The west coast has been an active continental margin for a long time — back, way back into the early Paleozoic and perhaps beyond into the Precambrian. I was born and grew up in this active geologic area.

When I was almost eleven, my family and I left the west coast semi-permanently and moved to the mostly inactive, even passive, continental margin of the east coast. The east coast — as geologists learned when the theories of continental drift and plate tectonics came together in the 60s and 70s — has been, for the most part, tectonically inactive since the Paleozoic era, with a smattering of activity in the Mesozoic, and even less activity since then (though not entirely zero). It took geologists years to figure out how plate tectonic theory could apply to such a long dead area (geologic history here and here). It’s now known to be a passive margin.

I never felt truly at home there: the mountains were not mountains, the coastlines were not coastlines — unless we drove all the way to Maine — and no huge masses of granite stuck out anywhere to provide a feeling of solidity or to remind me of home. Eventually, I found pieces of home in the granite quarry of Mt. Airy, North Carolina, and in unakite outcrops hidden somewhere amongst the creeping, overgrown underbrush of the Blue Ridge Mountains (unakite = altered granite). I was also rather partial to the kyanite of Willis Mountain, and enjoyed looking for twinned staurolite crystals. These, and other rocks and minerals, are reminders of the the Appalachians' earlier, more tectonically active heydey, but I was not introduced to them until relatively late in my east coast stage of life. I was a geologic orphan.

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When I returned to the west in 1975, I bypassed all known modes of geologic transportation — continental drift, wind and river transport, landslide, fault creep, thrust faulting, and valley rifting — and, instead, traveled across the continent in my ‘72 Opel, with everything I owned fitting inside except my full length mirror. I deposited myself like a graded bed on the east side of the Sierra Nevada and once again drew renewed strength from its high prominences and great length.

I was now in the province of the intermountain west, an area of complex and still unfolding geology, an area of tension and extension that formed, and still form, the quite obvious elevation extremes of basins and ranges that reach from the Sierra Nevada to the Wasatch Range. (Reno, Nevada, and Salt Lake City, Utah, are moving away from each other at a rate of about ½ inch per year.) The topography is simple and seemingly endless: up and down, up and down, up and down: corrugated or not corrugated, depending on how you like to characterize things. Dutton (1886) described our western ranges as looking like "an army of caterpillars crawling northward" — ranges of the Basin and Range province crawl northwestward across Arizona toward Nevada, and crawl northeastward across Nevada toward the Snake River plain.

I was also in a region shaped by tectonic processes more subtle than those that created the definitive horst-graben topography of the Basin and Range, processes that were active long before the land now known as California even existed — before magma arose from the melting zone deep beneath the west coast’s subducting plate to form a batholith that is intermittently present from at least Mexico to the northern reaches of Canada, and even into Alaska. First, sedimentary layers and volcanic flows had accumulated in former oceans and basins; then, as part of repeated accretionary events beginning in the Paleozoic, western siliceous cherts, siltstones, and pillows had been pushed over eastern carbonates along a thrust fault hundreds of miles long: the Roberts Mountains Thrust.

Carlin Unconformity

I was in a land of slammed-together accreted terranes, of compression and obduction, of province-wide, low-angle reverse faults. I was also in a land of thin and hot crust, a land whose huge-caldera volcanism and volcanic pyrotechnics in the Tertiary could easily make the eruptions of Mt. St. Helens, Mt. Mazama, Mt. Pelé, and Krakatoa look puny. In short, I was in the Great Basin — a region that overlaps with the Basin and Range province but is by no means identical to it — where all rivers, creeks, and dry washes flow inward into inland lakes or dry playas, and not outward to the sea.

I was, at long last, in Nevada.

Nevada, the silver state, has long been known for its bonanza gold and silver, and has more recently been known for its no-seeum, low-grade, disseminated gold (not so low-grade anymore, but that's another story). After moving here, I expanded my horizons: Carlin-type gold deposits in 1976, eastern Nevada in 1980, and the Mojave desert in 1981. Because of my own expansion, I gradually came to know that I was in the land of detachment faulting: a land where extreme extension and tectonic denudation have exposed the tortoise-shell–shaped cores of metamorphic core complexes that cut through the North American Cordillera in a band running from north-central Mexico into British Columbia. Detachment faults — large, low-angle normal faults of regional extent — separate the ductilely deformed cores from the broken and faulted rock formations lying tilted and detached above.

I moved here in 1975 and have been extended, disseminated, and detached ever since.

Some References:
Cathro, R.J., 2010, Nevada-type gold deposits (Part 4): CIM Magazine, v. 5, no. 7, p. 88-90.

Dutton, C.E., 1886, Mount Taylor and the Zuni Plateau, p. 105-198 in Volume III of Report of the Secretary of the Interior; being part of the Message and Documents Communicated to the Two Houses of Congress at the Beginning of the First Session of the Forty Ninth Congress in Five Volumes: Washington, Government Printing Office.

Gilbert, G.K., 1890, Lake Bonneville: U.S. Geological Survey Monograph 1, 438 pp.

McPhee, John, 1981, Basin and Range: Farrar; Straus & Giroux, New York.

Troxel, B.W., and Wright, L.A., 1987, Tertiary extensional features, Death Valley region, eastern California: Geological Society of America Centennial Field Guide-Cordilleran Section, 1987, p. 123-132.

Seeking Exposure

USGS Photo: Grand Canyon National Park, Arizona. Sunset on Cedar Ridge on South Kaibab Trail. July 12, 1957, by E.D. McKee.

Field camp had been planned to be a rather usual affair, to be located somewhere in the overgrown, fault-erratic littered, carbonates of the greater Blue Ridge Mountains of the Appalachians. It was an upcoming event that I really hadn't give much though to, other than to think things like, "Well, maybe we'll map even more faults down valley drainages for lack of good exposure." It wasn't that I wasn't looking forward to field camp, which would theoretically make me a geologist, at least more of one than those who hadn't yet attended, but I was thinking it would simply be more of the same thing: a few more trilobites and ever more limestones. I'd tell you that they were all Ordovician limestones, but you probably wouldn't believe that, and I'd only be exaggerating. I had, however, long since discovered that guessing Ordovician as an age on an invertebrate Palaeontology test gave better than even odds of guessing right, and Silurian and Devonian weren't far behind for good guesses in case you thought you'd overused Ordovician. (Always know how to play the odds.)

Also, serving a sentence term in an overgrown, kudzu-infested, hot and humid field camp wouldn't be getting me any closer to my ultimate goal, that of returning to the west coast as soon as possible. I was, after all, already six years past the unrealistic deadline I had set for myself when I was going on eleven years old.

Fortunately, due to unforeseen and overall unpleasant circumstances, I ended up taking two semesters off at the end of my junior year, and I ended up working downtown at the Smithsonian Institute (pushing papers, not rocks or fossils). It was my dad who suggested that I go to field camp somewhere in the west, a thoughtful suggestion made as a not-quite-desperate attempt to pull me out of the gray, cloudy and smoggy doldrums I had fallen into.

USGS Photo: Coconino Sandstone at O'Neill Butte,
viewed from Kaibab Trail, July 1957, by E.D. McKee

And so, the application process — of which I remember very little — began, and I applied to several field camps, finally deciding on a camp that would begin by hiking part way into and then out of the Grand Canyon, and would end up at a mapping project in the Swisshelms.

USGS Photo: Sunset Crater, by E.D. McKee. A real volcano!

Yes! Bright, brilliant geology everywhere, just the way I had always — after growing up near the Sierra Nevada — thought it should be. And rocks besides limestones! And volcanic rocks that weren't old and decrepit greenstones of nearly unimaginable age!

My geologic imagination was reignited at field camp in Arizona, and my goal to return west hardened. I came to Nevada a mere two years after my western, bright sunshiney, wide open field camp experience.

The story still makes me smile. ☺

The first rendition of this story for an unpublished Accretionary Wedge, Accretionary Wedge #11: Field Camp, includes a few stories.

This post is an entry to Accretionary Wedge #27, hosted this month by Lockwood at his favorite coffee shop (and blog of that name) Outside the Interzone. Go there to read about more significant geological experiences.

Where it All Began

OR

"How Did a Nice Girl Like You Become a Geologist, Anyhow?"

As continued from How did I become a Geologist?

I was often asked this question, especially in my early years as a geologist — the question was usually asked by strangers, mostly men, who I had just run into out in the field: prospectors and would-be prospectors, landowners, ranchers, and even other geologists. Really, you'd think people could be a little more inventive than to reuse that worn phrase so many times. The question seemed to imply some kind of wrongness in my choice of careers, and some other kind of wrongness that I'd managed to meet them out in the field — a "field" where I presumably didn't belong.

I've run into that question from Yuma to Gabbs, from Hog Ranch to Okanogan, and from Juneau to Fairbanks, and I wondered at the question every time it was asked. (The song Tucson to Tucumcari seems to be a most applicable song: my exploration travels have taken me, on legitimate business, to the places in the song: Tucson, Tucumcari, Tehachapi, and Tonopah.) I usually stuck to my routine answer, "My dad was a geologist," an answer that made sense and explained everything, at least it did for all those who asked the question. It didn't really explain things to me, nor did it tell the curious or suspicious questioners much about me.

The Making of a Geologist:
I'd like to say that it all started on Highway 8A, in Nevada, but it didn't. Nor, I suppose, will it end there, although it could. It all really started before I was born.

I was conceived and born while my dad was in grad school continuing his studies as a geologist at UO. Upon my birth, we moved almost immediately to central California, where I grew up with the foothills of the Sierra Nevada as my backyard playground, and with the northern Sierra Nevada towering above me. In those days, you could see the Sierra from Sacramento, you could see Half Dome from the Central Valley (you still can, just not routinely), and you could see Mt. Shasta from a bridge on Highway 40, now I-80, the road to San Francisco (at least, that's the way I remember it).

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I began life downstream from the headwaters of the McKenzie River of the southern Cascades, where I was like a little geologic formation myself, filling in the lowlands of a wide valley. The deposition and formation of my early life continued after my parents moved to another vast lowland: the Great Valley of California. Sediments formerly and actively depositing from seas or rivers, and rivers meandering and flowing between levee walls to the delta and into the bay, were all a part of this early life of mine — a life buttressed by the strength and continuity of the granite of the Sierra Nevada batholith, which formed the backbone of my early life.

While I was growing up in this serene and stable-looking area, my dad was at work as a geologist (the area, which is not far from where faults of the San Andreas fault system run through the San Francisco Bay Area, is far from geologically serene or stable, as many of you know). We routinely traveled from there into the McKenzie River and Willamette Valleys, up and over the crest of the Cascade Mountains, and up and down the Oregon coast; we meandered around the Sierra Nevada foothills, into the Sierra Nevada, to Yosemite and Lake Tahoe; and we made these traverses during all the seasons of the year.

The Carlin Unconformity, with old Highway 40 and the Humboldt River meandering past.

Roadcuts were magnets to my father, so we stopped and looked at them any time we went out for a drive. We collected rocks everywhere we went, and we went to lots of places. By the time I was five, I had seen the famous unconformity in Carlin Canyon, NV, and I had collected slate from eastern Nevada, granite from the Sierra, andesite from the foothills, asbestos from northern California, and agate from Oregon.

It probably also helped that I have rock collectors on my mother's side of the family, and that I grew up inspecting (and adding to) their collections of agate, geodes, barite roses, and other seashore and desert goodies. All these connections, collections, and early explorations combined might be enough to make a geologist out of anyone, but my brother, less than three years younger than I, who remembers much of this time period, did not become a geologist.

What truly did it, I think — what made me into a geologist, that is — was that I was born with a North Arrow in my head: you know, the kind of north arrow you find on any good map, one that continually and consistently points north. I guess that's a little like asserting that I was born with little magnetite or iron oxide pieces in my brain, so I can navigate the way geese or other birds supposedly do. Anyway, as far back as I can remember (possibly back to 1 or 1.5 years old), all my memories come with accurate north arrows engraved on them: that window faced east, that bed faced north, that street ran east-west, and you turned south into that driveway.

It's possible that later knowledge and directional orientation (when did it start?) has superposed North Arrows on my old memories, but maybe not: the arrows hold true for houses I was in when I was ≤1 years old, ≤1 to 4.5 years old, 4.5 to 5 years old, 5 to 6 years old, and so on. I have only revisited one or two of the early houses as an adult, and two of the early houses I have not revisited at all. For the latter two houses, my North Arrow memories check out with the house-detail memory of my mother ("Well, after you came in the front door, the master bedroom was immediately to the left...") along with the directional memory of my dad (who doesn't remember where the rooms of the houses were but does know that the front door faced east).

My dad was also born with a built-in North Arrow, as far as I can figure out, and consequently has been turned-around only once in his life. (I've been lost or turned-around three times that I can remember: once in fog, once in a dense forest, and once in fog in nearly impenetrable brush.) My natural directionality and 3-dimensional thinking (the latter is a requirement to be a geologist and the former is highly recommended) were both reinforced every time we, as a family, traveled anywhere or stopped at any roadcut. Probably the words north, south, east, and west were in my vocabulary by the time I was three, along with the words rock hammer and roadcut, so it remains a little difficult to pull out the built-in part from the added-to-later part — but the built-in part was there, of that I am sure.

That, anyway, is one way to make a geologist, although I'm sure there are other ways. One thing that geologists are sure of is the existence and viability of other ways — this idea is technically referred to as "multiple working hypotheses," and it's sometimes overstated as, "if ten geologists mapped the same area, you'd end up with at least ten different maps."

This story may be continued in another form later...

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Seatrain I'm Willin' on the Seatrain album (1970)

A classic road song.

Unakite!

I thought about following a recent trend of daily rock, outcrop, and mineral posts by making one such post per week, then reality hit me over the head and I backed off. This week, however, I have a nicely polished specimen of unakite to show off, even though the specimen isn't mine: I photographed it in Alaska.

Although currently residing in Alaska, this chunk of unakite is from the Blue Ridge Mountains of Virginia. (It's been around.) Unakite, a gemstone sometimes used as a building stone, is a metamorphosed or altered former granitic rock, with a type locality in the Unaka Range of the Great Smoky Mountains of eastern Tennessee and western North Carolina. Callan Bentley describes the origin of typical Blue Ridge Mountains unakite as being a 1.1 billion year old granitoid that got metamorphosed "during Alleghanian mountain-building, between 300-250 million years ago."
This enlargement shows an epidote veinlet cutting some of the reddish pink potassium feldspar in the upper right corner. That's an antique 10X Triplet hand lens for scale.
Here you can see a tiny quartz veinlet cutting the pistachio-green epidote, the reddish-pink K-spar, and the irregular gray masses of quartz.

I first visited the locality where this unakite was collected way back in my undergrad days while on a field trip led by W.D. Lowry. Later, probably while on an outing to some great camping location in the Blue Ridge Mountains, I visited this site with my entire family. My dad collected this particular piece of unakite—somewhere east of Charlottesville, on an east-west road south of the main east-west road heading west from Charlottesville (now I-64), on the west side of the mountains.

I thought maybe I could find the location in Google Street View, but that search was pointless until I did a little research on unakite localities near Charlottesville. And guess what? I think I found our site: somewhere on Highway 56 about one to two miles east of Vesuvius, VA, near an old unakite quarry, possibly between this roadcut and this roadcut. There's a chance that we were on some back road south of Highway 56, but still somewhere within the general Irish Creek–Big Mary's Creek–Little Mary's Creek unakite collection area of Rockbridge County, VA.

I have my own unakite around somewhere, either on a shelf or in a box at the lake. It's one of my favorite rocks, probably because of it's spectacular color, and also because it's likely one of the first rocks I collected as a budding, first- or second-year geologist. (Or maybe a Virginia trilobite was one of my first collections?)

Ron Schott's unakite pebble.

Andrew Alden's polished unakite.

Firsts

Photo from Talking Proud.

A meme of sorts has been started: What was your first geology field trip - by Geology News, and What was your first geology tool, by the Lost Geologist.

On the first subject: I took many field trips at very young ages to places like Yosemite, Lake Tahoe, and Crater Lake, and also traveled across the country at the age of 5 collecting rocks from roadcuts (I may still have a few of those rocks). My first formal geology field trips took place during my third quarter of college (1971) and in the years immediately following. Many of the field trips were short affairs, going to roadcuts to draw the structure, seeking out stream bottoms to find outcrops of mostly Ordovician strata and finding occasional trilobites while doing so, and traveling across the wide, green countryside looking for thrust fault erratics. One trip that stands out particularly in my mind was a trip taken during an Economic Geology class to a kyanite mine. Perhaps this trip stands out because not only was the kyanite fun to collect, it was probably my first tour through a mine and mill. I don't have any pictures from that trip as far as I know. The photo above is a picture of the largest producing kyanite mine in the world at Willis Mountain, Virginia; it is probably the mine we went to on the field trip. More photos of the kyanite mine and the countryside surrounding it can be found at Talking Proud.

The company mining the kyanite, Kyanite Mining Corporation, is the same company that was producing in the 1970's. Their history, more photos, and a bit about how kyanite is now processed can be found through links on their home page.

On the second subject: the first geology tool that I remember thoroughly was my dad's Brunton compass (I probably had a rock hammer and hand lens prior to field camp; those are long gone). I first had use of that compass when I went to field camp in 1973; I kept the Brunton and used it for work for a very long time, into the 1980's, when I was finally given a company compass to use. Sometime after that, I reluctantly returned the old Brunton compass to my dad; he presumably has been using it to carefully measure strikes and dips up and down all of Alaska's many paved roads, and possibly up and down the Alcan. Now, if he will submit a photo of the compass to this blog, I will duly post it. (The posting of that photo might have to wait until I get a new computer; I have only limited means when editing these posts, and adding photos after posting is something I don't think is possible under current operating conditions - no cursor movement!)

UPDATE: Kyanite Mining at Willis Mountain, Virginia - field trip at NOVA Geoblog.