BLM RAC: LOOKING FOR A FEW GOOD MEN AND WOMEN

The Bureau of Land Management (BLM) is the guardian of a very large parcel of public land in the state of Colorado- perhaps in excess of 8.4 million surface acres and controlling 29 million acres of subsurface mineral rights.  The BLM has a state office in Denver and Helen Hankins is the State Director (www.blm.gov/co/st/en.html).  The state is then divided into three districts:  Front Range District with headquarters in Canon City, the Northwest District headquartered in Grand Junction, and the Southwest District with offices in Montrose.  In addition, each of the District Managers is responsible for several field offices (that also have Managers).  For example, the Front Range District Office (FRDO) manages most BLM lands in Colorado east of the Continental Divide and has field offices located in Canon City (Royal Gorge), Saguache (San Luis Valley) and Salida (Arkansas Headwaters Recreation Area).  Each of the three state Districts have a citizen’s advisory committee (~12 members) that meets quarterly (as do most districts located in the western states).  I serve on the Front Range Resource Advisory Committee (RAC) and would encourage other interested rock hounds to consider service on these important councils.  We recently have studied such diverse items as feral horse populations, the Over the River Project©, geothermal leases, shooting ranges, and gold mining.  Since I represent the “dispersed recreation community” (things like rock hounding and recreational gold panning), I am always interested in any legislation or rule changes concerning collecting of rocks, minerals and fossils, and proposed changes to land access.

The Front Range Resource Advisory Committee is seeking nominations (self nominations are fine) for five new members (including dispersed recreation activities).  The deadline for receipt of nominations has been extended to June 4.  For information see:  http://www.blm.gov/co/st/en/BLM_Information/newsroom/2012/blm_extends_nomination0.html

UTAH AMETHYST AND GEORGE CLOONEY

BIG ROCK CANDY MOUNTAIN, MARYSVALE, UTAH.  PHOTO COURTESY OF RAY BOREN AND NASA'S EARTH SCIENCE DIVISION

One of my favorite movies is a loopy flick entitled Brother Where Art Thou directed by those talented brothers, Joel and Ethan Coen, in 2000—a great film for an interesting year, Y2K.  The movie had many memorable scenes and some fantastic music including the song Big Rock Candy Mountain:

Oh the buzzin’ of bees in the cigarette trees

and the soda water fountain,

at the lemonade springs where the bluebird sings

on the Big Rock Candy Mountain.  

 

Check out the music clip at: http://www.youtube.com/watch?v=KSGuBNopzBw&feature=player_embedded

Hearing the song always reminds me of a student field trip in Utah to a pile of volcanic rocks near the town of Marysvale. The most “famous landmark” of these volcanics is, get ready, Big Rock Candy Mountain.  So, in the "which came first game", I was able to learn that the song is some sort of a depression-era folk tune attributed to Harry McClintock (~1928) and recorded by several other artists including Burl Ives and Tex Ritter.  Our instructor told us that members of the local population placed a hand-made sign near the mountain proclaiming it as Big Rock Candy Mountain and the name stuck.  Today it is a tourist attraction—and an area of interesting geology. 

The area around Marysvale (Piute County, south-central Utah) is dominated by Oligocene to early Miocene volcanic rocks (27 Ma to 19 Ma) associated with a large stratovolcano complex complete with calderas (Hintze, 2005) ---similar in many ways to the current Cascade volcanoes of Washington and Oregon.  The volcanic pile is composed of drab-gray debris flows, lava flows, ash fall tuffs, and pyroclastic flows (ignimbrites).  The brightly colored volcanic rocks at Big Rock Candy Mountain are the result of percolating hot magmatic waters bleaching the normally dark volcanic rocks and leaving behind red, orange and yellow iron oxide stains (Hintze, 2005).

Topaz-bearing volcanic rhyolites (extrusive igneous rocks, rich in silica) in Utah are perhaps best known from the Thomas Range in the western part of the state.  These rhyolites have produced the famous topaz crystals of Topaz Cove, and some other interesting minerals (see blog post on 1 March 12)

Similar rhyolite flows are present in the Marysvale area and have produced some of the same semi-rare minerals such as bixbyite and pseudobrookite, but not the nice topaz crystals.  To make up for the absence of large topaz crystals the rhyolite at Marysvale gives up beautiful, terminated, water-clear, purple-tinged, quartz crystals.  The crystals are lithophysal in nature and collectors must bang on the rhyolite with crack hammers to locate the cavities.  The collecting area is on BLM land (I think but make certain you check with the local office) about 3 miles north of town on US 89 and then west on a gravel road.

mike

PURPLE TINGED QUARTZ CRYSTALS (AMETHYST) IN A RHYOLITE CAVITY; AT MARYSVALE, UTAH.  FIELD OF VIEW ~3 CM. WIDE.

REFERENCES CITED

Hintze, L. F., 2005, Utah's Spectacular geology; How It Came To Be: Department of Geology, Brigham Young University, Provo.

FROM THE FILM

(Nothing to do with amethyst but my favorite quote; warped mind?)
MOVIE SCENE

Delmer, Pete and Everett sitting around a campfire "enjoying" dinner.

  

DELMAR: Care for some gopher? 
EVERETT (George Clooney): No thank you, Delmar. One third of a gopher would only arouse my appetite without bedding it down.
DELMER; Oh, you can have the whole thing. Me and Pete already had one apiece. We ran across a whole... gopher village. 

POST SCRIPT

So the question in my mind, and probably only in mine, is just exactly what were Delmer and Pete really eating down there in rural Mississippi in 1937?  Gopher--that much we know.  But "gopher" is sort of a generic term like "Coke" referring to just about any soft drink.  In the Midwest "gopher snakes" refer to Bull Snakes (Pituophis catenifer).  Gopher Tortoises (Gopherus polyphemus) are "land turtle" found in the southeastern U.S.  But, most people think of a "gopher" as some little furry creature that burrows into the ground.  And, in fact, there is a family of rodents known as the Geomyidae that are the Pocket Gophers.  In the movie, it was obvious the little animal roasting over the fire on the skewer was a small mammal, about the size of a Pocket Gopher, so count out the tortoises and snakes.  And, unfortunately, the Pocket Gophers since their range does not include Mississippi!  The roasting dinner was too small for a Woodchuck (Marmota monax) and too big for any of the "mouse" species found in the state.  The Eastern Woodrats (Neotoma floridans) might fit the size bill; however, I have never heard these animals called "gophers".  That leaves the Eastern Chipmunk (Tamias striatus), a furry little burrowing rodent, as the best suspect; but, it seems somewhat small compared to the roasting animal!  And, have you ever tried to catch a chipmunk?  Oh well, life goes on.

A MINNESOTA GOLDEN GOPHER---THE "REAL THING", AND FANS OF THE UNIVERSITY OF MINNESOTA BASKETBALL TEAM.  PHOTO COURTESY OF U OF M.

FROM THE FILM

THE U.S. CIVIL WAR AND UTAH LANDSCAPE

The years 2011-2015 are being remembered in the U.S. as the sesquicentennial of the American Civil War.  I have always been interested in this epic part of American history, but even more so during this remembrance period.  There are literally hundreds of books and articles being published each year during this celebration. It seems impossible to read all of them, or even browse the bookshelves.  A couple of months ago, in early March, Civil War buffs remembered the Battle of Hampton Roads, one of the most important naval battles in the nation’s history.

In 1861 President Lincoln decided on a policy of blockading ports of the Confederate states---part of General Winfield Scott’s Anaconda Plan to “strangle” the south!  Scott was known as “Old Fuss and Feathers”, and was Commanding General of the United States Army for the last 20 years of his 47 year career!  So, from Virginia down the Atlantic Coast and over into the Gulf Coast and up the Mississippi River, Union ships patrolled the waters trying to intercept Confederate ships (or sympathetic privateers, mostly British blockade runners) transporting supplies into ports, or out with cotton (for sale in Europe).  Although the blockade runners were fairly successful in getting in and out of ports, the small size of their cargo holds did not allow much commerce, and the Union captured somewhere in the neighborhood of 1500 ships over the course of the conflict.  In summary, the blockade was successful.

SCOTT'S PLAN TO STRANGLE THE C.S.A. WITH THE USE OF A NAVAL BLOCKADE.  PHOTO FROM LIBRARY OF CONGRESS.

One of the most important ports, to both the Union and the Confederacy, was the area known as Hampton Roads, the estuarine mouth of the James River as it flows into Chesapeake Bay.  Although the Confederacy controlled the south part of the estuary at Norfolk and Portsmouth, the Union had strongholds at Fort Monroe on the north (on the Virginia Peninsula) and Fort Wool on a small man-made island (Rip Raps) on the south side of the main channel.  Therefore, the Union was able to block the entrance to the channel and the Confederacy lost sea access to inland Richmond (their capital on the James River) as well as access to naval facilities at Norfolk.  In addition to the patrolling Union ships, the U.S. Navy anchored several other warships to strengthen the blockade (USS Cumberland, Congress, Minnesota, Roanoke and St Lawrence).    

However, the Confederate Navy had a little surprise for the Union blockade at Hampton Roads!  On March 8, 1862, the CSS Virginia (and the gunboat consorts CSS Raleigh and Beaufort, plus the Patrick Henry, Jamestown, Teaser) steamed down a tributary of the James (the Elizabeth River, above the blockade) and headed downstream to confront the Union gunboats.  The Virginia, commanded by Franklin Buchanan, headed straight toward the USS Cumberland, a sailing warship carrying perhaps 22 smoothbore Dahlgren shell guns and a larger aft Parrott rifle.  After pummeling the Cumberland with numerous shells the Virginia rammed the sloop-of-war below the waterline and she (all ships are referred to as feminine I guess) sank.  The Virginia then took aim the USS Congress, a 52 gun sailing frigate that had run aground.  After badly pounding the ship, hot cannon balls were sent flying into her powder magazine and the Congress sank.  The Virginia then went for the USS Minnesota, a steam-powered frigate and a former flagship of the Hampton Roads Fleet.  Unfortunately, the Minnesota had also ran aground and after a brief encounter with the Confederate ships, she was probably saved from destruction by the coming nightfall.

SKETCH OF THE CSS VIRGINIA.  NOTE THE BATTERING RAM ON THE BOW OF THE VESSEL.  PHOTO COURTESY OF THE U.S. NAVAL HISTORICAL AND HERITAGE CENTER.

There was a reason the CSS Virginia was so successful on that day in March 1862—she was covered with iron plates and the shots from the Union ships mostly bounced off the hulls!  Ironclad ships suddenly became a new player in U.S. naval history.

The Virginia actually begin her career as a 40 gun wooden frigate of the U.S. Navy.  As Union forces burned their fleet (mostly) during the 1861 retreat from Norfolk/Portsmouth, they left behind many remnants.  Since the USS Merrimac (or Merrimack) only burned to the waterline, the Confederate Navy hauled her up, retrofitted it with iron plates (an ironclad), and renamed it the CSS Virginia.  The Merrimack was a screw prop so the engines were mounted below the water line--a seemly good fit for the new ironclad.  But, as a retrofitted wooden ship, the Virginia was a very bulky vessel with a turning radius of perhaps one mile, an engine in need of a rebuild, and had 14 gun ports (four each broadside, three bow and stern, carrying a variety of weapons including 9 inch Dahlgren smoothbores, two 6.4 inch rifles and two pivot guns fore and aft (7 inch Brooke rifles capable of firing 104-pounds shells) (Olmstead and others, 1997).  Two of the Dahlgren,s were built to fire "hot shots, heated up in a special furnace.

After the carnage (~ 250 men killed, Cumberland and Congress sank, two transports and a tug sank, two frigates and a tug damaged, and a transport captured) the Virginia retired for the evening but returned the next day to finish off the Minnesota and to destroy, or at least disrupt, the blockade.  But, the Union had its own surprise---during the night the USS Monitor, commanded by John A. Worden, steamed into the estuary with an assignment to protect the Minnesota.  The Monitor was the Union’s first attempt at an ironclad and was built from the ground up and was not a retrofitted ship.  Therefore, it was much smaller and more nimble than the Virginia.  In addition, the Monitor carried only two, 11- inch Dahlgren shell guns but they were mounted in a revolving steam-powered turret.

USS MONITOR  SKETCH FROM COURTESY OF THE U.S. NAVAL HISTORICAL AND HERITAGE CENTER.

AN 11 INCH DALHGREN SHELL GUN.  PHOTO FROM COURTESY OF THE U.S. NAVAL HISTORICAL AND HERITAGE CENTER.

 

The Monitor and the Merrimack (most popular term for the Virginia) battled for over three hours on March 9 with most shells bouncing off the ironclad structures.  At times, they were almost touching each other and a Brooke rifle on the Virginia was able to hit the Monitor's pilot house dead on, injuring the Captain.  However, the faster Monitor was always able to maneuver quickly and stay between the Virginia and the Minnesota.  Finally, the battle seemed a draw and both vessels steamed off for repair and recuperation.  However, the course of naval history changed on that day, not only for the U.S. and C.S.A. but for the world.  Steam-powered ironclad ships were now the warships of the future. 

Interestingly, both the C.S.A. and the Union claimed victory in the battle but most historiams would call it a draw!  But, the blockade had been preserved for the Union but unfortunately (for the Union) the battle made Major General George McClellen alter his plans to march on Richmond so the Confederate capitol was saved for another day.



 on the

THE MONITOR VS. THE MERRIMAC AT THE BATTLE OF HAMPTON ROADS.  PRINT FROM LIBRARY OF CONGRESS.

So, now the burning question---how in the world does this Civil War naval battle relate to the geology of Utah?  The answer lies along UT 313 heading southwest off US 160 north of Moab toward Dead Horse Point State Park.  At about MP 4, two square-topped buttes appear to the northwest—Monitor and Merrimac Buttes!  The massive cliffs (seen in the photo below) are part of the Entrada Formation (Slick Rock Member) while the crinkly and folded redbeds below belong to the Dewey Bridge Member of the Entrada. Below the Dewey Bridge is the cross-bedded and wind-blown Navajo Sandstone while the juniper-covered Kayenta Formation occupies the foreground.  Capping the buttes are the Moab Member of the Entrada (white sandstone) and minor beds of the Summerville and Morrison formations.  The entire section is Jurassic in age.

MONITOR (RIGHT) AND MERRIMAC BUTTES.

Of course the Merrimac (CSS Virginia) is the more massive butte while the smaller is the USS Monitor.  Together they are locked in battle forever (or at least until erosion wears then down).  So, that is the story of how the U.S. Civil war arrived in Utah! 

REFERENCES CITED

Olmstead, Edwin; Stark, Wayne E.; Tucker, Spencer C., 1997, The Big Guns: Civil War Siege, Seacoast, and Naval Cannon. Alexandria Bay, New York: Museum Restoration Service.   

POST SCRIPT

• The C.S.A. Navy abandoned the ports around Norfolk and scuttled the CSS Virginia on May 11, 1862, rather than allow capture by Union forces.  The Virginia simply was too heavy to steam up the James to Richmond.
• The smaller USS Monitor was lost in heavy seas off Cape hatteras on December 31, 1862.  However, the U.S. Navy liked the design and constructed dozens of "monitor-like" ironclads for use in both river warfare and on the high seas.   
• The massive 11 inch Dalhgren shell guns weighed in at nearly 16,000 pounds. 
• The Captain of the Monitor stopped at the Flagship Roanoke, anchored in Hampton Roads, and offered to let any seaman off who did not want to continue with the battle.
• Bad weather delayed the arrival of the Monitor by one day.  perhaps the Congress and Cumberland could have been saved if the weather had cooperated.
• After writing this little article I discovered the April 2012 edition of "Naval History" (a journal) dedicated to the Battle of Hampton Roads.  Most interesting was a first-hand report written (actually dictated) by a Monitor seaman detailing the battle.
• An impact structure, Upheaval Dome, is located a few miles from Monitor and Merrimac Buttes.  The age is post-Jurassic.  
• An impact structure was created ~ 35 Ma. at the site of the current southern Chesapeake Bay.                     

  

  LOCATION OF IMPACT STRUCTURE IN CHESAPEAKE BAY AREA.  THE JAMES RIVER IS THE SOUTHERNMOST STREAM.  MAP FROM NASA.

  
  

  
  

  

  AERIAL PHOTO (FROM USDA) OF UPHEAVAL DOME NEAR MAOB, UTAH

  
  

AZURITE AT GOLD HILL

GOLD HILL ORE CHUTE

I recently noted the occurrence of the occurrence of adamite, a zinc arsenate hydroxide, in my miniscule collection of minerals from Gold Hill, Utah.  A couple of readers (wow, I didn’t know if anyone read these blogs or not ) confirmed the mammillary structures are goethite pseudomorphs after smithsonite!  Another reader suggested that the tiny acicular spray in the vug might be olivenite, a copper arsenate hydroxide [Cu₂(AsO₄)(OH)] that is common at Gold Hill.

In examining tiny pieces of minerals in my collection box I did notice “some blue” color.  I may be color blind with red-green-brown but can spot blue or purple (but I get them mixed up).  Initially I thought the streaks were linarite as a crust rather than small clusters of crystals.  Linarite is a secondary lead copper sulfate hydroxide that is found in the oxidation zone of ore bodies containing lead.  It has that beautiful azure blue color.

CRUST OF AZURITE WITH BOTRYOIDAL HABIT (TOUGH TO SE WITH THIS POWER).  LEFT TO RIGHT IS ~6.2 MM.

However, under high power of my binocular microscope I was able to notice a botryoidal habit rather than tiny crystals common to linarite.  This revived my brain cells and caused me to pull out the acid and I noticed the blue mineral “fizzed” indicating a carbonate.  So, I am now “guessing” (that is what paleontologists do with mineral identification) that the blue streak is common azurite, a carbonate of copper [Cu₃(CO₃)(OH)₂)], with a beautiful azure blue color.  So it goes.

By the way, the Rockpick Legend Co. in Salt Lake City has a wonderful collection of Gold Hill minerals and a great web site at:  

http://www.rocks4u.com/gold_hill.htm

mike

PHOTOMICROGRAPH OF AZURITE CRUST FROM GOLD HILL.  tHE FIELD OF VIEW IS ~2.4 MM.

WENDOVER WILL AND ADAMITE

WENDOVER WILL, ALL ~65 FEET WITH A MECHANIZED WAVING HAND, BECKONED VISITORS TO THE STATE LINE CASINO IN WENDOVER, NEVADA. AFTER 120 MILES OF BONNEVILLE SALT FLATS UTAHANS WERE READY FOR A LITTLE ACTION AND AN ADULT BEVERAGE.  PHOTO COURTESY OF WENDOVER HISTORY

Gold Hill is one of those classic collecting areas for Utah rock hounds, and those others pilgrims willing to travel to the far western reaches of that fine state.  Of course, the bi-state town (Nevada-Utah) of Wendover is on the route if one is interested in mining recent gold or needing a motel room and an adult beverage.

In the “old days” I had a research area down west of the Deep Creek Mountains to the south of Wendover and my crew always wanted to stop at the casino for a “good meal”.  They seemed not to really like my cooking campfire meals down in the desert!  So, it was off to the Stateline Hotel and Casino (currently operating as the Wendover Nugget Hotel and Casino), home of Wendover Will.  Seems like a entrepreneur by the name of Bill Smith operated a gasoline station in Utah (right east of the state line).  Never one to miss an opportunity,  when gambling was legalized in Nevada in 1931 Bill added a casino across the state line!  During the years that I was stopping in for a refreshment before heading to the desert, the vehicle was parked in Utah, we crossed a white painted line, and voila---we we in a different world with Wendover Will  welcoming all.

Leaving the world of bright lights and tinkling slot machines behind we heading south but often could not resist a side trip to the old mining town of Gold Hill, Utah.  I previously wrote about the mines and collecting conichalcite, a bright green copper calcium arsenate hydroxide, [CaCu(AsO₄)(OH)]---see that blog on December 8, 2011. The information sign at Gold Hill notes that the usual gold, silver, copper and lead were initially mined but when those minerals became depleted, the boom was over and the town became a ghost.  During World War I, arsenic was in demand as insect control for creatures devastating the cotton fields of the southern U. S.  So, Gold Hill opened up again and mined arsenates. 

COLORLESS AND VITREOUS ADAMITE CRYSTALS ON LIMONITE. SPECIMEN IS 4.3 CM WIDE.

Another mineral that Gold Hill is “famous for” is adamite, a zinc arsenate hydroxide [Zn₂ (AsO₄)(OH)]. Adamite is one of those minerals that usually occurs in the oxidized or secondary mineralized zone where zinc is present, and arsenic was in the hydrothermal solution. 

MODIFIED ORTHORHOMBIC AND COLORLESS CRYSTALS OF ADAMITE.  INDIVIDUALS ARE .5MM OR LESS IN LENGTH.

 Most of the Gold Hill adamite that I have seen is composed of very tiny crystal druses or ball-like clusters that are either yellow or various shades of green in color.  It appears that either iron or copper make some element substitutions.  However, pure adamite is colorless, transparent and quite vitreous. In fact, I paid little attention to my specimen of ademite from Gold Hill since I thought it was just “sort of a pretty” rock with numerous tiny quartz crystals.  But, much to my amazement, under high power of a binocular microscope those tiny crystals (mostly modified orthorhombic) turned out to be colorless adamite.  Some may have hints of very pale green but with my color blindness, it is hard to tell!

A VUG IN THE SPECIMEN CONTAINING AN UNKNOWN SPRAY OF MINERALS.  THE LONGEST INDIVIDUAL ROD IS ABOUT .5 MM.

CLOSE-UP PHOTOMICROGRAPH OF UNKNOWN MINERAL.  ANY IDEAS?

I tried to find other associated minerals in my small specimen,such as austinite, but no luck.  However, there are tiny mammillary structures that are either goethite or limonite, perhaps ?pseudomorphs after smithsonite.  And, there are a few sprays of an unknown mineral present!

PHOTOMICROGRAPH OF TINY MAMMILLARY STRUCTURES OF GOETHITE OR PERHAPS LIMONITE.  ARE THESE PSEUDOMORPHS AFTER SMITHSONITE?

I just need to revisit Gold Hill and do some dump digging; however, it is a fair trip from the Springs and with the price of diesel….!  But wait, all I would need is a couple of lucky pulls on the machine :)
mike

CARTOON OF MODIFIED ORTHORHOMBIC CRYSTALS COMMON TO ADAMITE.