President’s Column – December 2011

Title: Happy [Geologic] Trails To You

Author: Ira Pasternack

Publication: The Outcrop, December 2011, p. 8-10

Article Type: President’s Column

Another year is about to pass so it is time to finish my columns with a few final geologic thoughts that I hope are of interest.

The spot gold price has retreated from recent historic highs in August and September of over $1,900 an ounce, so a brief discussion of the precious metal’s long and essential part of Colorado history is warranted. The first documented report of gold in Colorado was around 1805 by trapper James Purcell who found gold along the South Platte River (Cappa, 2003, Dorsett, 1970). Purcell told his story to Zebulon Pike while both were being held in a Santa Fe jail for trespassing. Pike was leading an expedition evaluating the Louisiana Purchase when he and his group were arrested for accidentally wandering into Spanish territory. Three centuries earlier (almost 500 years ago!), Spanish conquistadors had mounted several unsuccessful campaigns in the area searching for rumored lost cities of gold.

The discovery of gold in Colorado was not accidental as it had been in California in 1848. Prospectors heading west to participate in the California gold rush of 1849 noted good potential for placer gold deposits in the streams flowing out of the Front Range. In the spring of 1858, a group of unsuccessful California prospectors returned to Colorado to try their luck along Cherry and Ralston Creeks and the South Platte River near the present site of Denver. They only recovered very small quantities of gold, but news of the find spread and a rush to the “Pikes Peak Country” followed. By the end of 1858, about 1,000 prospectors had arrived and several settlements sprang up in the Denver area. The first commercial gold placer deposit in Colorado was discovered by G.A. Jackson close to the mouth of Chicago Creek near Idaho Springs in January, 1859 (Koschmann and Bergendahl, 1968). The news of Jackson’s discovery quickly spread and was followed by a frantic rush of prospectors into the neighboring area. In May 1859, J. H. Gregory discovered the first lode deposit of gold-bearing quartz veins in outcrops along the North Fork of Clear Creek near Blackhawk. The following month, W.G. Russell discovered placer gold in Russell Gulch near Central City.

Colorado ranks second among the States in total gold production, with an aggregate production of about 41 million ounces through 1965 (Koschmann and Bergendahl, 1968). (California ranks first with more than 106 million ounces produced between 1848 and 1965). There are 44 gold mining districts scattered across 24 Colorado counties that have each produced more than 10,000 ounces. Most of the gold mining districts occur within a northeast trending region, known as the Colorado Mineral Belt, that extends from near the southwestern corner of the state to near the town of Boulder. Cripple Creek is located southeast of the Mineral Belt and was among the last of the gold mining districts discovered in 1891. Cripple Creek is one of only four gold districts in the United States that has produced more than 10 million ounces. The only active large scale gold mining operation remaining in Colorado is run by AngloGold Ashanti and produced 233 thousand ounces last year from their Cripple Creek mine. Considering the lengthy 150-year history of gold mining in Colorado, 233 thousand ounces remains a significant amount of production and crucial contribution to Colorado’s economy.

When I mentioned the sad news about the first Mars Exploration Rover (MER) named “Spirit” failing to reawaken and efforts to communicate with it being ceased in my July column, I was unaware that a new rover dubbed “Curiosity” was well in the works. “Curiosity” will be the most technologically advanced surface robotic rover ever sent to another planet when it is launched (hopefully) during a window between November 25th and December 18th. If all goes well, Curiosity will land on Mars during August, 2012.

Curiosity is about twice the length of Spirit and its twin, Opportunity, approaching the size of a small car. The scientific payload being carried by Curiosity is ten times more massive than the earlier rovers and consists of ten instruments including a gas chromatograph, mass spectrometer, and a “Mars Hand Lens Imager” capable of resolving details smaller than the width of a human hair.

One of the most remarkable aspects of the development of the Curiosity mission is the technology being utilized to land the rover at its selected target site. A complex system will enable steering to land within a 12-mile long target area, about five-times more precise than past Mars landings. This has enabled selection of a target site that previously was considered too risky near the foot of a mountain inside Gale crater. The mountain appears to be bedded based on evaluation of high resolution images from the Mars Reconnaissance Orbiter and the beds are believed to contain minerals that formed in water. The portion of the crater floor where Curiosity will land consists of an alluvial fan likely formed by water-carried sediments. Selection of the Gale crater followed consideration of more than 30 Martian locations by more than 100 scientists participating in a series of open workshops.

The advanced scientific payload carried by Curiosity will provide the most sophisticated attempt to find evidence for conditions that would have been favorable for microbial life and for preservation of fossils in the Martian rock record. Best of luck Curiosity on your mission!

As I mentioned in the August President’s Column, I have been fascinated by dinosaurs since my youth and was excited to learn of a recent study result on the famous Tyrannosaurus rex specimen, Sue (Hutchinson, et al, 2011). The team of researchers working at Chicago’s Field Museum recently put Sue, the largest and most complete Tyrannosaurus rex specimen ever found, and four other related skeletons, through multiple tests to better understand how the dinosaurs grew and moved. The team used three-dimensional scans of the mounted skeletons to generate fleshed-out digital models that enabled accurate estimates of the dinosaur’s mass. Sue, weighed in at over nine tons, or 30 percent greater than previous estimates.

The research team also considered the growth rate of Tyrannosaurus rex, estimating that during the most rapid teenage period of growth, they gained 3,950 pounds a year, or eleven pounds a day! Despite the increase in weight, the study maintained support for the relative consensus among scientists that peak speeds of 10 to 25 miles per hour were possible for Tyrannosaurus rex. Perhaps not the speeds depicted in Jurassic Park movies, but still pretty scary when you consider this was an animal that weighed more than four automobiles combined that was capable of speeds faster than the best sprinter can average over a mile.

It is time to wrap up this column with a few final words of gratitude before I head off into the proverbial sunset. RMAG simply could not function without the staff and volunteers who work tirelessly to provide members services and support for the local geologic community.

Joshua Robbins and Carol Dalton are owed a debt of gratitude for their efforts administrating the organization even though short-handed much of the year. Sandi Pellissier has left the organization after 15 years of service to RMAG. We appreciate her contributions and wish her well. Josh has done a particularly fine job in developing the new RMAG website this year which has improved member’s access to all things RMAG including publications and functions.

The Continuing Education Committee, Ron Pritchett (chair) and Steve Veal (Board liaison) are commended for their efforts coordinating the symposia and short courses this year. I particularly want to commend John Robinson and Mark Sonnenfeld for their efforts on the timely and informative Fall Bakken Symposium. Neil Sharp did a great job lining up speakers for the monthly Wednesday luncheons.

The Publication Committee, Bill Pearson (chair) and Dean DuBois (Board liaison) are commended for their coordinating efforts. The Mountain Geologist editors Joyce Trygstad Nelson and Melissa Klinger did a great job transitioning from Jeanette DuBois and Joy Rosen-Mioduchowski. The Outcrop editors Kristine Peterson, Cat Campbell, Holly Sell and Jane Estes-Jackson also did a great job, transitioning to a new digital era for the publication. I know they were not happy about the change to the digital format, nor were the Board and many members, but this will enable substantial savings to RMAG for not having to print and mail the Outcrop. Jane Estes-Jackson and Donna Anderson are gratefully acknowledged for their editing efforts on the Niobrara publication. John Robinson, Julie LeFever and Stephanie Gaswirth are also gratefully acknowledged for their editing of the Bakken publication. A big thanks to Charlie Bartberger for all of his editorial help and suggestions with these columns.

I want to acknowledge the RMAG Foundation for all of the excellent work they do in supporting geologic and related research. Laura Wray deserves special recognition for serving five years on the Foundation, well beyond the standard three-year term. Jim Huck has ably assumed the Foundation chairmanship as Laura stepped down.

I want to thank the members of the 2011 Board for all of their efforts, including Pete Varney (President-Elect), Dean DuBois (1st Vice President), Steve Veal (2nd Vice President), Heather LaReau (Secretary), Dave Eby (Treasurer), Larry Rasmussen (Treasurer-Elect), Ed Dolly (1 Year Counselor), and Mark Sonnenfeld (2 Year Counselor). Best of luck to Pete, Mark and Larry and the rest of the 2012 Board for a successful New Year.

Finally, I want to thank all the RMAG members for without your continued participation and support the organization would cease to exist. Thank you all very much. It has been a privilege and a pleasure to be the 2011 RMAG President. It really has been a special year for me, and made me appreciate what a special place it is that we live, how special our profession and colleagues are, and what a special organization RMAG is.

I’ll finish with one of my favorite quotes, attributed to Charles M. Russell in 1925: “Any man that can make a living doing what he likes is lucky, and I’m that.”

Selected References and Websites:

Gold:

Koschmann, A.H., and M.H. Bergendahl, 1968, Principal Gold-Producing Districts of the United States: U.S. Geological Survey Professional Paper 610, 283 pp. Downloaded 8/27/11 from: https://pubs.usgs.gov/pp/0610/report.pdf

Cappa, J., 2003, Gold! Gold! Gold!, RockTalk: Colorado Geological Survey, vol. 6, n. 2, p.1- 8. Downloaded 8/27/11 from: http://coloradogeologicalsurvey.org/wp-content/uploads/2013/08/rtv6n2.pdf

Keller, J., 2003, Colorado’s only active gold mine–Cripple Creek & Victor Gold Mining Company, RockTalk: Colorado Geological Survey, vol. 6, n. 2, p. 8-12. Downloaded 8/27/11 from: http://coloradogeologicalsurvey.org/wp-content/uploads/2013/08/rtv6n2.pdf

Brochure on Colorado Mine Tours, downloaded 10/2/11 from: http://mining.state.co.us/pdfFiles/Tourist_Mine_Brochure.pdf [link no longer active]

Dorsett, P. F., 1970, The story of Colorado’s gold & silver rushes, Barnes & Noble Books, New York, 434 pp.

Mars:

Curiosity Mars Space Laboratory Rover: NASA Mars Space Laboratory website: http://www.nasa.gov/mission_pages/msl/index.html

Mars Space Laboratory Fact Sheet: http://marsprogram.jpl.nasa.gov/msl/news/pdfs/MSL_Fact_Sheet.pdf

Cool animation illustrating Curiosity’s mission: http://www.nasa.gov/multimedia/videogallery/index.html?media_id=97780842

T.Rex:

Hutchinson JR, Bates KT, Molnar J, Allen V, and Makovicky PJ, 2011, A Computational Analysis of Limb and Body Dimensions in Tyrannosaurus rex with Implications for Locomotion, Ontogeny, and Growth. PLoS ONE 6(10): e26037. doi:10.1371/journal. pone.0026037. Downloaded 11/01/11 from: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0026037

California Academy of Sciences, Bulked-Up T rex, October 17, 2011 Top Story. Downloaded 11/1/11 from: http://www.calacademy.org/sciencetoday/bulked-up-t-rex/ [link no longer active]

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