UTAH PETRIFIED WOOD AND FLOWER CHILDREN

This is a two part story—one concerning South Dakota in 1967 and the second describing some petrified wood collected from Utah in 1968.  I hope that you will see the relationship!

In summer 1967 I was working in South Dakota for the State Geological Survey and trying to finish up my MS thesis.  My work took me to several sections of the state but at virtually every location my field assistant and I heard the musical anthem of the summer—San Francisco (Be Sure to Wear Flowers in Your Hair).  It was a haunting and peaceful song that sort of stuck in your mind and you wanted to hum along:

If you're going to San Francisco
Be sure to wear some flowers in your hair
If you're going to San Francisco
You're gonna meet some gentle people there

For those who come to San Francisco
Summertime will be a love-in there
In the streets of San Francisco
Gentle people with flowers in their hair

All across the nation such a strange vibration
People in motion
There's a whole generation with a new explanation
People in motion people in motion

It was the ultimate “flower power” song of the generation and sort of chronicled, and invited, gentle people to visit the city during the “Summer of Love”.  Now, in 1967 I was not about to wear flowers in my hair and instead sported a western battered black hat.  But, I was a dreamer and sort of wondered what it was really like in California.  Was it all peaceful and gentle with a perpetual spring?   However, my Midwestern, small-town, strong parental care upbringing did not allow me to “drop out” and join the migration.  I needed to work, I liked my job, and I needed to graduate, etc.  Later in life I did stop at Haight and Ashbury to see if any magic remained.  The only thing I saw-- several “old hippies” getting their picture taken by the street sign so they could return home and lie to their grand children: Yah, I was there for the love-in and saw Janis Joplin belt out a song.  Of course kids, I didn’t run around naked and I didn't inhale!  In 1967 the area was home to music by Jefferson Airplane, the Grateful Dead, and Big Brother and the Holding Company.  The place was rocking to a variety of "hard" music (for those days).  Back in the "hinterlands" the best we could do was crank up the 50,000 watt KOMA 1520 AM out of Oklahoma City--but only after after sunset!  Baby Boomers all over the Plains and Mountain West would head to their cars and run down the 6 volt batteries in short order listening to the latest hits of Rock n Roll.

In fall 1967 I had a “big week” as I graduated from South Dakota, traveled to Kansas, got married, and drove to Utah for more graduate school.  All worldly items were packed in our car—a 1959 Pontiac with a portable roof carrier.  Of course in those days such a car seemed about 50 feet in length (actually only 18) and was powered by a mighty 285 hp engine; the trunk was enormous.

A 1959 PONTIAC SIMILAR TO THE BEAST WE DROVE TO SALT LAKE CITY. NOTE THE SIZE OF THE TRUNK, AND THE "FINS".  WOW. PHOTO COURTESY OF WWW.CARNUT.COM.

 Actually, we were somewhat terrified as Salt Lake City approached—a couple of kids from small towns on the plains going to the “big city” (250k people then).  With less than $250 on hand we found a landlord willing to let up pay rent in two week increments.  But, I wanted to teach in a university and getting that degree was the path to that job.  It all worked out in the end—I graduated, got the university position, stayed in higher ed for 36 years, and am still married to the same wonderful person.  Life is good. 

One of the first places that I explored in Utah, looking for a dissertation project,  was a few miles east of Salt Lake City near an old mining town called Park City (if only I had bought property then).  This back valley (back of the Wasatch Mountains) was filled with early Tertiary “volcanics”, all sorts of wind-blown and water-lain tuffs intermixed with eruptive volcanics derived from the "Park City volcanic field".  In fact, hard-rock mining for metals (associated with the volcanics) commenced in ~1889 and lasted until the 1950’s.  Currently the local population mines the tourists who arrive by the tens of thousands!  

PARK CITY MINING DISTRICT, SILVER KING COALITION MINING COMPANY, CA. LATE 1800'S.  PHOTO COURTESY OF MININGARTIFACTS.HOMESTEAD.COM.

 Near Park City is a road intersection known as Silver Creek Junction, about where the current I-80 intersects with US 40.  Many of the rocks in this area seemed to have been deposited in a wet area or pond or something like that and petrified wood was common.  Much of it was opalized and sort of a yellow to orange color and was quite beautiful.  Today the land is developed and private, and generally collecting is off-limits as owners do not appreciate rock hounds digging holes.  I have one piece of that wood from those early collecting days.

PETRIFIED WOOD COLLECTED FROM SILVER CREEK JUNCTION.  WIDTH ABOUT 10 CM.

 OK, how does this Utah tidbit tie into Scott McKenzie?  In working on my dissertation I needed access to back country roads/trails between Park City and Evanston, Wyoming, and could not afford a jeep or pickup.  So, I purchased a 90 cc Kawasaki dirt bike and off I went.  In 1968 the “migration” to California by drop outs and/or partakers of magic potions was still evident and Utah was on the main road.  On one trip up a small highway to a back valley I came upon a VW bus trailing blue haze out the windows and chugging along, straining the engine.  Now, that Kawasaki was not the fastest bike in the world but it was speedier than the VW!  As I passed them with a wave I could see eleven long-haired friends of Jesus in a chartreuse microbus (as C. W. McCall sang in Convoy) singing along to McKenzie’s song blaring on the radio—they were heading west with a smile on their face and magic weeds in their pocket. 

In fact, the 1960’s always reminded me of Charles Dickens’ description of the French Revolution (from A Tale of Two Cities, 1859): it was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us, we were all going direct to heaven, we were all going direct the other way.  The 1960’s were tumultuous to say the least and they certainly influenced the country (and the world) for decades to come.  However, they were interesting and I enjoyed my time during that period.  So, today whenever I hear San Francisco (Be Sure to Wear Flowers in Your Hair) on the “oldies station” I get a little nostalgic as it brings back brings back pleasant memories of youth--

Those were the days, my friend
We thought they'd never end We'd sing and dance forever and a day
We'd live the life we choose
We'd fight and never lose
For we were young and sure to have our way

                                                             sang by Mary Hopkins, 1968

  And, I begin to dream: would that bike have made it to San Francisco?

Rest in Peace Scott McKenzie (1939-August 2012). 

mike

STUMBLING UPON A FAIRBURN AGATE

FAIRBURN AGATE, 2012.  WIDTH IS ~5 CM.

I get sort of euphoric when stumbling upon an agate in the field (here defining an agate as included or banded chalcedony)!  I don’t really prioritize agates in my collection; however, I do have several different specimens representing a variety of “types”.  Of course, my favorites are the Fairburns, the official state gemstone of South Dakota.  Perhaps my fondness is due to a Fairburn ending up as the first “really good” agate that I collected---way back in the 1960’s.  Perhaps it is due to my allegiance to the state of South Dakota where I once picked up a university degree.  Perhaps it is because they are beautiful specimens and quite colorful!  Whatever the case, I like Fairburns (and Teepee Canyons; see my previous blogs on August 18 and June 17, 2012).  Both postings delve into great detail about collecting sites so will not be repeated here.

At any rate, I was back on the Fairburn beds in summer 2012 and for the second year in a row was successful!  Finding a Fairburn of any sort is becoming a nice accomplishment these days so I am quite pleased with my specimen.  It is not the nicest in the state, nor would it make the agate collecting books.  But, it is mine and that makes me happy!

mike

POLYMORPHS: ANATASE AND BROOKITE

Last Saturday I took the opportunity to attend a local estate auction where the handbill advertised thousands of rock, mineral and fossil specimens.  I thought---sure, “thousands”, no way and they are probably junk.  What a pleasant surprise was in store as there were “thousands” of specimens and while some were junque, many more were very nice and collectable.  Most of the fossils were local Cretaceous baculites and really not collectable.  There were also flats of pretty unspectacular microcrystalline quartz available and some went for quite a few bucks!  Why?  But then there were nice collectable individual specimens thrown into flats (beer cases) with about two thirds carrying correct labels.  Some of the flats contained specimens from a single locality such as unlabeled topaz-bearing rhyolite from western Utah.  Most other flats were mixed with perhaps the most interesting being opal (looked Australian) with barite (almost certainly Hartsel, CO).  I guess the packer saw that both were “shiny”. 

I had a great time visiting with, and bidding against (although very hard), about 9-10 other members of CSMS.  I would guess that the ten of us purchased the great majority of the collectable specimens.  The auctioneer would start out with a flat and request bids for any single specimen or two and then sell the remainder of the flat at a single price.  I thought that some of my buys were “quite good”!

One partial flat that I purchased had a small crystal of anatase, something that was not in my collection and a mineral not all that familiar to me ---but I wanted it.  So for $5 I was able to “get it” along with a beautiful, water-clear, double terminated, scepter quartz crystal, a piece of rhodochrosite (with crystals), a nice terminated apatite crystal, some gemmy-green, titanite (sphene) crystals, and several other specimens.  A great buy.

Driving home I kept probing the back recesses of my mind—what do I know about anatase?  Where had I seen specimen(s)?  Then something popped out, or turned on, and I remembered by blog about the mineral brookite (March 7, 2012).  There must be some relationship!  So, in examining the posting I noted my words, and there it was—anatase:  Brookite is a titanium dioxide, TiO_2, crystallizing in the orthorhombic system.  MinDat notes that brookite is one of five titanium dioxide minerals (rutile, anatase, akaogiite, unnamed) that occur in nature---all belong to different crystal systems!  So, anatase is a polymorph of brookite!

Anatase is in the Tetragonal System while brookite is orthorhombic; both are usually found in primary sources as single crystals.  I say primary since all of the polymorphs are not rare in concentrations of heavy minerals from sedimentary rocks.  Anatase has a hardness of about 5.5-6, an adamantine to metallic luster, and a dark steel blue to black color.  The source for the larger crystals seems to be secondary and derived, via hydrothermal solutions, from titanium-bearing minerals in igneous and metamorphic rocks (www.MinDat.org)

 

The specimen now in my collection has a label indicating that Minas Gerais, Brazil was the place of origin.  All-in-all, it was an exciting day.  Now, off to finding shelf space!

 

Anatase crystal from Brazil partially covered with a “clay mineral”.  Width at junction of crystal and clay is ~5 mm.

Brookite crystal from Arkansas.  Length is ~1.75 cm.

ADDENDUM, 5 June, 2103.  Partial large crystal of anatase from Cuiaba District, Minas Gerais, Brazil.  Length ~2.0 cm.

 

CRACKING ROCKS AT TEEPEE CANYON:AGATES

BISMARCK LAKE NEAR CUSTER, SOUTH DAKOTA-VIEW FROM THE CAMP SITE.

I have visited the Teepee Canyon agate area a couple of times in the last few years, but without much success.  On my initial visit I did not have the proper equipment and my undersized rock hammer was of little use.  I found a few agate fragments but certainly nothing to write home to momma about.  On my second visit I ran into a rain storm and the roads did not look very passable and I am somewhat terrified of lightening.  My momma did not raise no fools!

TEEPEE CANYON AGATES AT THE AMERICAN FEDERATION 2012 SHOW.

 But, I am persistent and in summer 2012 I was bound and determined to go back to the Canyon and pound on the rocks.  Teepee Canyon is located approximately18 miles west of Custer, South Dakota, about 2 miles west of Jewel Cave National Monument off U. S. 16.  As soon as travelers leave the Monument they should look to the west, up slope, and begin to spot piles of broken rocks, big pieces.  Sawmill Spring Road, (FS 456) leads off to the west and about a mile further West Teepee Canyon road takes off.  My best advice is to follow one of these roads/tracks and look for quarries where past prospectors have tried their luck.  The land is managed by the U.S. Forest Service and all previous claims have expired (as I understand it).  The gentleman in the local USFS office in Custer told me that only hand tools were allowed and to stay in the area of previous mining (I left the big fircrackers in the vehicle).  It is my understanding that after the fire of 2000 other agate producing areas external of the main Teepee Canyon site had been discovered.  I don’t know if these are claimed.  What I do know is that there are enough “big rocks” at Teepee Canyon to last me a lifetime!

THE DIGGINGS AT TEEPEE CANYON. 

 The agates are located in chert nodules housed within the lower Minnelusa Formation.  I suppose these nodules are the result of silica-rich meteoric waters circulating through the unit with resulting diagenesis producing the chert.  Why some nodules are agatized—I don’t have the slightest idea.  Just as I am uncertain how/why agates really form!  The formation of agates in several types of rocks is extremely complicated, even for the “experts”.

The Minnelusa sits on top of a widespread carbonate unit termed the Mississippian-age Madison Limestone, or the Pahasapa Limestone as it is generally known in South Dakota.  In the early part of the Pennsylvanian (younger than the Mississippian) the climate was warm and quite wet in the future South Dakota and a red soil developed on the Madison.  Later in the period marine waters returned and rocks of the Minnelusa were formed. The Minnelusa is an interesting rock unit composed of beds of sandstone, dolomite, and thick beds of anhydrite.  Braddock (1963) noted that dissolution of some of the anhydrite had caused numerous collapse structures and collapse breccias in the Black Hills.  Originally designated as Pennsylvanian in age, fossils in the Minnelusa indicate both a Pennsylvanian and Permian age.  I presume that since the agates seem to be in the lower part of the formation, they belong to the Pennsylvanian.  I was able to locate brachiopods in some of the beds at Teepee Canyon but am uncertain as to their exact age.

CHERT NODULES IN MINNELUSA FORMATION.

BRACHIOPODS IN MINNELUSA FORMATION.

The nodules at Teepee Canyon are composed of chert, often red to tan in color, and of various sizes.  Very few of these nodules are agatized so locating a good agate is “hard work”.  First of all, the enclosing carbonate matrix is mostly a fine-grained dolomite that is extremely hard and quite difficult to “break”; hence, the need for a large crack hammer, eye protection, heavy clothes, and preferably steel-toed boots.  Many prospectors/miners at Teepee Canyon have cut into the outcrop and removed “really large” pieces of dolomite to crack open.  I decided early on that sort of mining was not on my agenda and simply cracked open smaller pieces mined by others.  The nodules in the carbonate were quite numerous and it appeared, at least to me, that some of these would polish quite nicely.  But, I was after agates!  I found numerous smaller pieces, all fragments less than one-half inch long, but then—there it was, a real Teepee Canyon agate.  Now, it is nothing spectacular, perhaps 1.25 x 1.0 inches in size, but never-the-less it was mine, and it satisfied my yearning!  So, after about two and one-half hours of cracking rocks in a hot sun I decided to take my find and return to camp on beautiful Bismarck Lake by Custer State Park.

AGATE ROUGH COLLECTED SUMMER 2012.

RED SOIL DEVELOPED ON TOP OF MADISON FORMATION NEAR JEWEL CAVE NATIONAL MONUMENT.  SOIL FORMED IN A WET AND WARM CLIMATE.

 mike

REFERENCES CITED

Braddock, W.A., 1963, Geology of the Jewel Cave SW Quadrangle, Custer County, South Dakota: U.S. Geological Survey, Bulletin 1063 G.