FACETED SPURS: SIGNS OF MOVEMENT

THE PATRIARCH, OR IS IT MATRIARCH?

Faceted spurs are common, fairly easy to recognize, landforms found along the flanks of mountains in the western U. S. where active, or recently active, faults are present.  As the mountain ranges are uplifted, streams cut into the rocks and flow toward master streams located in the down-dropped and adjacent valleys.  Ridges are formed between the mountain streams and usually slope gently toward the adjacent valleys.  However, if bounding faults are active, a fault scarp (cliff) forms along the edge of the mountains.  This scarp has the tendency to truncate the interfluve ridges (spurs) and create a triangular shaped “faceted spur”.  Along the west flank of the Catalina Mountains north of Tucson, Arizona, the bounding Pirate Fault has created numerous faceted spurs that are quite evident from Catalina State Park.  These triangular features seem common on outcrops of the Tertiary Wilderness Suite Granite.

In south central Colorado, the east side of the San Luis Valley is bounded by the Sangre de Cristo Fault along the western side of the Sangre de Cristo Range.  The northern part of the range, usually referred to as the Culebra Range, is separated from the adjacent San Luis Basin by the Crestone Section (a large normal fault = mountains “up” and basin “down”) of the master Sangre de Cristo Fault (Ruleman and Machete, 2007).  This fault extends from Poncha Pass, the northern-most boundary of the San Luis Basin, south to the Great Sand Dunes (McCalpin, 1982).  The deepest part of the basin seems to lie adjacent to the Crestone Section where there may be 30,000 feet of sediment (Garca and Kind, 1965). 

The Culebra Range and the adjacent Crestone Section Fault are characterized by a steep-walled mountain front with well-developed faceted spurs.  Many of the fault scarps are developed on very recent late Pleistocene and Holocene alluvial deposits.  (McCalpin, 1982, 1986).  This would indicate movement along the fault within the last 10,000 years.

REFERENCES CITED

McCalpin, J.P., 1982, Quaternary Geology and Neotectonics of the West Flank of the Northern Sangre de Cristo Mountains, South-central Colorado: Colorado School of Mines Quarterly, v. 77, no. 3.

McCalpin, J.P., 1986, Quaternary Tectonics of the Sangre de Cristo and Villa Grove Fault Zones, in Rogers, W.P. and Kirkham, R.M., eds., Contributions to Colorado Seismicity and Tectonics—A 1986 update: Colorado Geological Survey Special Publication 28.

 Ruleman, C. and M. N. Machette, 2007, An Overview of the Sangre de Cristo Fault System and New Insights to Interactions Between Quaternary Faults in the Northern Rio Grande Rift in Ruleman, C., M. N. Machette, M-M. Coates, and M. L. Johnson, eds., 2007 Rocky Mountain Section Friends of the Pleistocene Field Trip—Quaternary Geology of the San Luis Basin of Colorado and New Mexico, September 7–9, 2007: U. S. Geological Survey Open-File Report 2007-1193. 

mike

WEST FACE OF SANTA CATALINA MOUNTAINS.  THE PIRATE FAULT LIES UNDER THE SEDIMENT AS THE MOUNTAIN FRONT HAS RECEDED.  THE FACETED SPURS ARE GEOLOGICALLY OLDER (TERTIARY) THAN SIMILAR FEATURES ALONG THE SANGRE DE CRISTO MOUNTAINS.

WEST FACE OF THE SANGRE DE CRISTO MOUNTAINS AT NORTHERN END OF THE SAN LUIS VALLY.  MOVEMENT ALONG THE CRESTONE FAULT IS GEOLOGICALLY YOUNGER THAN THE PIRATE FAULT IN ARIZONA.

GOOGLE EARTH IMAGE OF SANTA CATALINA MOUNTAINS AND ADJACENT FEATURES.

GOOGLE EARTH IMAGE SHOWING EXTREME NORTHERN END OF SAN LUIS BASIN AND ADJACENT FEATURES.

HOHOKAM PETROGLYPHS

A DANGEROUS HUG!

One of the really interesting locales in south-central Arizona is Casa Grande Ruins National Monument near Coolidge (about one-half way between Tucson and Phoenix).  The site was given the designation of archaeological reserve by President Benjamin Harrison in 1892 (the first such designation).  In 1918 President Woodrow Wilson declared the site a National Monument.  The National Park Service (NPS) refers to the inhabitants and builders as Ancient Sonoran Desert People but most people simply call them the Hohokam.  They evidently were agrarian people and farmed the desert with the help of an extensive system of canals, mostly along the Gila and Salt Rivers.   The NPS believes the Hohokam lived in the area for over a thousand years until around 1450.  At Casa Grande the people built a "big house” (Spanish = casa grande) that the NPS believes is one of the largest prehistoric structures ever built in North America; remains of the four story “house” are still visible today.

While hiking with, and following, my brother in the hills south of Casa Grande (I was actually looking for zeolites in the basalt) we were treated to the sight of hundreds of Hohokam petroglyphs, and foundations of some sort of ?buildings.  While the buildings at Casa Grande are composed of caliche, all we observed were rock foundations.

 

I have observed numerous petroglyphs (“pecked” into rocks) and pictographs (painted on the rocks) in the red rocks of the Colorado Plateau, and even in my native Kansas on the Dakota Sandstone.  The Colorado Plateau glyphs and graphs are the work of artists associated with the Barrier Canyon Culture and the later and better known Fremont Culture.  However, this is the first time that I have observed glyphs on basalt boulders.  But, I guess artists work with the media available!

mike

A BUILDING FOUNDATION?

LIZARD GLYPH

A STORY WITH A LIZARD

BIGHORN SHEEP

SANTA CATALINA MOUNTAINS

SANTA CATALINA MOUNTAINS LOOKING EAST FROM STATE PARK.  BOUNDING PIRATE FAULT RUNS THROUGH AREA IN FOREGROUND.

The Santa Catalina Mountains dominate the skyline east of Tucson and are a typical Basin and Range chain with large bounding normal faults on either side.  West of the Catalinas (along the highway) is the Canada del Oro Basin, a graben filled with several thousand feet of sediments eroded off the high mountains.  The coalescing alluvial fans (debris shed off the retreating mountains) from the Catalinas seemed to have merged with similar fans coming off the Tortolita Mountains (west of the Basin) about one Ma (Bezy, 2002) (Fig. 6).  Most of the sediment in the Basin is composed of pieces of granite, schist and their mineral components such as feldspar, quartz and muscovite.  This seems logical since the western mountain front is composed dominantly of different types of granite emplaced during the Precambrian (Oracle Granite, 1.45 Ga) and the Tertiary (Wilderness Suite Granite, 45-50 Ma; Catalina Granite, 26 Ma) (Bezy, 2002) (Fig. 7).

The major drainage along the western front of the range is the south-flowing Canada del Oro with tributaries coming down from the mountains and joining it at right angles.  Most likely this rather straight-flowing stream follows the course of the western bounding fault termed the Pirate Fault.   Mt. Lemon at 9157 feet is the highest point in the Catalinas and has a ski resort---not a very good proposition in most dry winters.  The name, Santa Catalina, may have been bestowed by a Jesuit priest, Eusebio Francisco Kino, who was busy converting the Tohono O’odham (local Native Americans) to Catholicism in the late 1600’s.  As with many places in the west, Spanish miners soon followed in the footsteps of the proselytizing priests.  They evidently found placer gold in a creek and named it Canada del Oro or Gulch of Gold, a name that has intrigued me for the several years that I have been coming to Tucson. 

The area also has its share of lost mine stories, although nothing to quite match the Lost Dutchman up at Apache Junction.  Most of the tales seem concerned with the Iron Door Mine (gold) and La Esmeralda (silver) in the northern section of the Catalinas.  Clay Thompson of the Arizona Republic in the 10 December 2007 edition reported: “at some point in the 1750s or 1760s Jesuit missionaries feared for their lives, either because of a revolt by their Native American charges or because of attacks by the implacable Apaches.  So they stashed a whole bunch of silver and gold in either a mine or a cave somewhere in the mountains north of Tucson and sealed it with a heavy iron door - minas de fierro con puerta en la Canada del Oro. Then the Jesuits lit out for friendlier environs, and over time the exact location of the treasure was lost.

Lots of people have searched for it over the years, but obviously, no one has ever found it, if, indeed, it is there to be found.  One of the people who believed in the legend was Buffalo Bill Cody, who owned some mines in the area at one time and looked around a bit for the Mine With the Iron Door.

In 1923, a popular storyteller named Harold Bell Wright cranked out The Mine With the Iron Door, a novel featuring brave and honest prospectors, a plucky orphan girl, a wrongly accused hero and a couple of villains named Sonora Jack and Lizard.  The novel was made into a movie of the same name in 1924 and again in 1936.”

There is at least one region, the Southern Belle District but sometimes referred to as the Catalina or Oracle District, that actually has produced both lode and placer gold.  The mine, “a former surface and underground Au-Pb-Ag-Cu-W-silica mine”, evidently was closed in 1964.  “Mineralization is a tabular ore body” hosted in rocks of the Precambrian Apache Group (exposed between the Oracle Granite and the Catalina Granite).  Mineralization in the quartz veins “is probably associated with a Lower Cretaceous-Tertiary intrusive period” (www.mindat.com). 

I have thus far been unable to gain access to the Southern Belle property, so I did the next best thing—grabbed my gold pan and tried to locate a placer deposit in Canada del Oro.  I did find a single small piece of flour gold but not much else.  Toole (2007) suggested that since the stream course contained 60-200 feet (actually I think it is much greater) of “overburden” then the gold would be down on the bedrock.  But he also opined that perhaps a metal detector (which I do not own) could locate surficial nuggets. 

My lack of success with the pan is probably the norm for Canada del Oro.  It appears that for several years after members of the local Native Americans quit discouraging exploration, miners tried to make a living with placers but activity seemed unsustainable over the long term.  Wilson (1933) reported “numerous old pits, trenches, and tunnels indicate considerable early placer mining, and many thousand dollars worth of gold are reported to have been recovered.  The production recorded from 1903 to 1924, inclusive, amounted to $11,351 [this was at $20 gold] …During the 1932-1933 season, approximately thirty men intermittently carried on small scale rocking and panning in the Canada del Oro region, chiefly on the northern side of the creek.  Although one $25 nugget [1.25 oz] and a few $5 nuggets [.25 oz.] were reported, the average daily returns per man were seldom more than fifty cents”. 

REFERENCES CITED

Bezy, J. V., 2002, A Guide to the Geology of Catalina State Park: Arizona Geological Survey, Down-to-Earth 12.

Toole, D., 2007, Where to Find Arizona’s Placer Gold: Delos Toole Gold Books, Salem, Oregon.

CANADA DEL ORO BASIN IN MIDDLE DISTANCE.  LOOKING WEST FROM CATALINA MOUNTAINS WITH TORTOLINA MOUNTAINS IN FAR DISTANCE.

GOLD, GOLD, GOLD AT TUCSON

CALIFORNIA GOLD

CALIFORNIA GOLD NUGGETS

MORE CALIFORNIA GOLD

51.2 POUNDS OF AUSTRALIAN GOLD

ANOTHER PERSPECTIVE

GOLD "FOR SALE"

Today, 10 February, was the opening day of the annual Tucson Gem and Mineral Show held at the Tucson Convention Center.  As usual, parking in downtown Tucson was aggravating and difficult; however, I was there shortly after the opening bell.  The show’s theme, Minerals of California, would indicate the presence of some fantastic specimens of Elbaite, Benitoite, and Gold and I was anxious to observe.  I was not disappointed and could only gaze in wonder at some of the most beautiful minerals in the world.  However, the star of the show may have been the 51.2 pound Ausrox gold nugget from Australia.  It was hard to realize that the monster was an actual piece of solid gold; my brain failed and was unable to convert pounds to ounces times $1364 spot plus the bonus for specimen gold!

TUCSON ELECTRIC PARK SHOW

The Tucson Electric Park/Kino Sports Complex Gem and Mineral Show is an event held prior to the main Tucson Gem and Mineral Show and is a gathering rock hounds will not want to miss if in the Tucson area.  The Show, usually held the first two weeks of February at the sports complex, is just off I-10 in the southern part of town.  There is no admission charge and an advertised 20 acres of free parking complete with shuttles— major selling points for a fun and inexpensive time.   Well over 250 vendors display wares at the Show and that is the main attraction---the funky items for sale are diversified, to say the least.  There are large jade tigers, at least a million beads, chairs constructed from petrified wood logs, enough dop sticks to supply the CSMS group for decades to come, thousands of pieces of costume jewelry plus some high end blue topaz (guaranteed non-heated treated!), the largest tumblers in the world, wooden canes, “Navajo” rugs with a tag stating “Made in PRC (China), trilobites by the thousands (including numerous fakes), the self described Amethyst Capital of Tucson, and since this is Arizona—several rifles and pistols.  I was somewhat fascinated with the fake trilobites as most were really bad—the bugs were cast in a black resin and then cemented to a gray limestone with matching gray cement.  Put on a few tool marks and throw it on the “For Sale” table.

On the other hand, there were some really nice mineral specimens for sale at reasonable prices.  I found the best displays, and the least expensive minerals, at a section of the event called the RV Show. This area included “mom and pop” shops, and individuals, both living in their parked RV’s and displaying their collections on tables.  Most were very interested in visiting with potential customers and many had some very nice specimens.  This frugal rock hound was able to purchase some really nice water-clear, yellow-orange, wulfenite crystals collected from the “79 Mine, 4^th level, Hayden, Gila County, Az” for $1!  A collector who lives near Grand Junction, Colorado, was showing, and selling, a fantastic collection of Utah Lace Opal collected from his claim near Milford, Utah.  But perhaps the most impressive specimens, at least to me, were some of the giant crystal quartz points collected in Brazil.

So, everything at the show is free to look at and the parking is easy and free—a great way to spend an afternoon or a day.  The displays are often quirky and who would not want to take home some genuine plastic turquoise beads.

mike

Carved Tiger

Petrified Wood Chair

Take Home A Crystal Skull

A Quite Large Quartz Crystal Point

Buy Your Genuine Coon Skin Hat

Always an Amethyst Cathedral

CSMS 2011 OFFICERS

CSMS 2011 Officers

The annual CSMS banquet and officer installation was held 20 January at the Best Western hotel in north Colorado Springs.  President Ron "Yam"Yamiolkoski passed the gavel to incoming President Roger Pittman (who also served a few years ago); however, Yam will continue on the Board as Past President and 2011 Show Chair.  Other officers include Kay Thompson--Vice President; Ann Proctor--Treasurer; Joan Peterman--Secretary; Roni Poteat--Membership Chair; Teri Stoiber and Ann Proctor--Editors; Sharon Holte and Al Zelenak--Members at Large.  Life Member Ray Berry administered the "oath of office".  Bob Germano, Jennifer Beisel, David Olsen, and Drew Malin rotated off the Board (thanks for the service).  The Society also was honored by the attendance of several life members, including Roy Wilson (50 years), Kay Thompson, Eloise Berry, Charles Webb, Steven Veatch, Raymond Berry, Jack Thompson and Michael Wheat.  Mike Nelson gave the address, "Geology and Physiography of Colorado".  Frank Rosenberg serves as the "official" photographer.

mike

Life Members with Roy Wilson holding the pick

Yam and Roger

Bill & Betty Cain, active in the Rocky Mtn. Federation