Arizona Geological Society

Welcome to the Arizona Geological Society

Upcoming events - Register Here!

04 Dec 2018 6:00 PM • Sheraton, 5151 E Grant Rd. (& Rosemont), Tucson AZ 85712
05 Feb 2019 6:00 PM • Sheraton, 5151 E Grant Rd. (& Rosemont), Tucson AZ 85712

Other Events

November 13, 2018 -Arizona Hydrological Society Meeting at Montgomery and Associates, 1550 East Prince Road, Tucson.,  6:30 - 8:00 PM, Thomure, Director, Tucson Water will speak on the "Status of the Aquifer" 

December 1, 2018 - U of A SME Student Chapter 23rd Annual Diggers and Duffers Gold Tournament - Fundraiser - 7:30 AM to 2:00 PM

December 1, 2018 - 36th Annual Mining Hall of Fame Awrds Banquet and Fundraiser, 6:00 - 9:00 PM at J W Marriott Tucson Starr Pass Resort and Spa, 3800 West Star Pass Blvd., Tucson

December 2-3 2018 - 2018 SME Arizona Conference at JW Marriott Starr Pass Resort and Spa

An End of an Era at Superior, Arizona

At 8:46 AM on Saturday, November 10, 2018, Resolution Copper demolished  the historical copper smelter stack at the Magma mine near Superior, Arizona.   Deemed structurally unsound, this 293-foot structure was toppled in a controlled blast as a part of a larger reclamation effort at the West Plant site, which began in 2005 and is scheduled to be completed in 2020.  To date, $40 million has been spent on Resolution Copper's rehabilitation efforts at Superior.  When completed in 2020, the estimated cost of this project will be approximately $80 million.

William Boyce Thompson and George Gunn incorporated the Magma Copper Company in May 1910 to develop recently acquired mining properties in the Superior area.  These holdings became known as the Magma mine, which achieved production during 1911.   During early development of  the site, supplies were brought in by horse or mule drawn wagons from a railhead near Florence, Arizona.  High-grade direct smelting ores were hauled to the railhead on the return trip for trans-shipment to ASARCO's newly commissioned smelter at Hayden, Arizona.

Over the years, additional infrastructure was added to handle increased production from the Magma mine.  A 200-ton/day concentrator was placed on line in April 1914 and a 36-mile narrow gauge rail line, connecting Superior with the Phoenix and Eastern Railroad at Magma Junction near Florence, was completed in May 1915.   Magma Copper's smelter was commissioned in March 1924, eliminating the need to ship ore or copper concentrates to a distant smelter.  This facility operated until July 1971, when it was closed in an effort to reduce costs.  Following its closure, copper concentrates from the Superior operation were treated at Magma Copper's San Manuel smelter. 

After 71 years of production, Magma Copper suspended operations at Superior in August 1982 due to high operating costs and declining copper prices that fell to 73 cents/lb.  With the rise of copper prices during the late 1980s, mining operations resumed in September 1990.  Magma Copper's successor, Broken Hill Proprietary Company Ltd., suspended all mining and milling operations on June 28, 1996 after depleting its remaining mineable reserves.

Discovered by a deep exploration drilling program in 1995, the Magma porphyry system is currently being readied for production by Resolution Copper Mining LLC, a 55/45 joint venture owned by Rio Tinto and BHP-Billiton.  To date, nearly $1.2 billion has been spent on this project, which is scheduled to commence production in approximately 10 years.  Located at a depth of 4,900 to 7,000 feet, this high-grade deposit is reported to contain a  resource of nearly two billion tons, averaging 1.54% Cu and 0.035% Mo.    It will be capable of producing nearly 25% of the United States' annual copper demand over its projected mine life of 40 years.

AZGS New Video on Fissure Damage in Apache Junction

On 9 Aug. 2018, ~ 2 inches of rain fell on Apache Junction in northern Pinal County. An existing earth fissure there reopened and undermined a section of Houston Avenue that had collapsed in the summer of 2017 (see aerial photo above).

The recent collapse was triggered by a van driving across the undermined section of road. Fortunately, the driver was not injured (Figure 2); a tow truck hauled the van to safety. Today’s Arizona Geology blog post has more details.

Joe Cook and Brian Gootee examined the road collapse and used a drone to capture aerial video of the fissure between E. Baseline Ave and Houston Ave.

AZGS AZ Mining Review Superior, Az., 1930-1950

Author and sociologist Joaquin Trujillo, Ph.D., discusses the life and times of a copper mining town, Superior, Arizona, during the Great Depression, WW II, and the post-War years. For a summary of Dr. Trujillo’s 300+ page book, see the Arizona Geology Blog post:Living Superior, Arizona: The life and times of a copper mining town.


AZGS AZ Mining Review Tours Florence Copper

On 24 July 2018, the Arizona Mining Review team joined Dan Johnson, Vice President & General Manager of Florence Copper, and Stacy Gramazio, Manager of Communications & Public Affairs, for an early morning tour of the pilot in-situ copper recovery (ISCR) facility outside Florence, Arizona. 

Florence Copper is in the final stage of deploying a $25 million production test facility, designed to harvest 1.5 million pounds of copper annually for several years. Following successful proof of concept, Florence Copper has plans for a larger plant to recover 55 million pounds of copper annually for the first 6 years, and 85 million pounds annually for another 14 years. Over a 20-year lifespan, Florence Copper estimates the recovery project will yield ~$3.4 billion dollars in revenue. 

In-situ copper recovery is a 3-phase process: Phase 1 - injection of the active fluid (99.5% water with 0.5% sulfuric acid) with a pH similar to household vinegar; Phase 2 - extraction of the pregnant, copper-rich solution; and, Phase 3 – using electrowinning, a process first pioneered in the Globe-Miami area in the late 1960s, to produce ~ 100-pound copper cathodes that are 99.999% copper. 

The Arizona Mining Review is funded in part by the Mining Foundation of the Southwest.

U of A Gem & Mineral Museum

Bob Downs, Univ. of Arizona Mineral Museum Curator & Prof. of Geosciences, is leading the effort to build out a University of Arizona Gem & Mineral Museum (UAGMM) at the former Pima County Courthouse in downtown Tucson. Building renovation is well underway with the museum scheduled for a soft opening at the Courthouse in Jan. 2020.

Two of the museum’s chief organizers, Eric Fritz (Mgr.) and Les Presmyk (Mining Engineer & mineralogist), approached AGS’s Jan Rasmussen (former Curator of the Arizona Mining and Mineral Museum in Phoenix) and AZGS’s Mike Conway about helping design an exhibit focusing on the geology of Arizona.

Jan and Mike have begun pulling together ideas for an Arizona geology narrative – one idea involves building a digital display showcasing Ron Blakey’s marvelous paleogeographic reconstructions of the Colorado Plateau and environs, complemented by geologic scenes, lithologies, and interviews as the cornerstone of the exhibit. 

HELP! But we want your help in gathering ideas on the elements of narrative (with visuals) expounding on Arizona’s geologic history. In short, we want your ideas, sketches, brainstorms, and musings to help us rough out a draft design by mid-July 2018 – 3 weeks away!  This is an important opportunity for you to influence a future wide audience about Arizona geology.


Arizona Geology Exhibit. Approximately 75 square feet is set aside for an Arizona Geology exhibit. An additional 15 square feet is provided for a porphyry copper display. (Will Wilkinson. FMI retired, is taking the lead here.)  

Audience. UAG&MM organizers anticipate a largely non-science audience of considerable age range and with limited knowledge of geologic concepts.

Timeframe. Time is short. AGS & AZGS representatives meet with the UAG&MM design team in mid-July, so the sooner you share your ideas the sooner we can begin evaluating them.  

Financial Resources.  Bob Downs, Eric Fritz and others in the management will pursue the financial resources for final exhibit design and construction.

How to help! Please send your ideas, sketches, and experiences gleaned from other mineral or natural history museums to Mike and Jan at the e-mail addresses below. We can meet to brainstorm ideas before the July 3 AGS meeting to discuss ideas.

 Mike Conway
 Jan Rasmussen
 AGS Treasurer and AZGS
 AGS Member and Consultant

November 2018 Newsletter

Dinner Meeting Sponsor for November 2018


The Arizona Geological Society is grateful for Boart Longyear's sponsorship, which helps us offset the costs of our dinner meetings and other activities of the society.

If you are interested in sponsoring one of our dinner meetings, please contact:

For Cancellations or Changes Please Contact

Student Dinner Sponsor for 2018

Arizona Geological Society is grateful to Freeport-McMoRan, Inc. for their generous support of our student members!

Freeport-McMoRan is sponsoring student dinners for the 2018 AGS monthly meetings.

AZGS Hires an Economic Geologist

We are delighted to announce that the AZGS offered the position of Research Scientist in Economic Geology to Carson Richardson this week, and he has accepted the offer. Carson is a Ph.D. candidate in the Dept. of Geosciences, University of Arizona. He is finalizing his Ph.D. research and will join our staff in January 2019.


We received ~35 applications, interviewed 7 candidates, and brought in 4 finalists for presentations and interviews. Each of the finalists has strong qualifications for this position, and we appreciate their willingness to share their ideas with us.


Carson’s chief task will be to build an economic geology program to support our mission to ‘provide technical advice and assistance to industry while encouraging the wise and prudent use of Arizona lands and mineral resources.’ He will join our geologic mapping efforts, focusing on mapping and assessing mineralized zones. He will also track mining trends in Arizona and will be the Survey’s primary liaison to the mineral exploration and mining community.

Carson on Outcrop of Breccia


Bio. Carson Richardson grew up near Peru, Indiana – the amateur circus capital of the world. He received his BS in Geology and Anthropology from Ball State University in 2012, and his MS in Geosciences from the University of Arizona in 2014. He has continued at UA working on a PhD, with an anticipated graduation date of Spring 2019. Carson’s research interests span economic and structural geology, but with particular emphasis on understanding the magnitude and timing of post-ore extensional faulting and its implications for the modern distribution of mineral resources.

2018 AGS Spring Field Trip to Jerome

Overview of the United Verde Pit

On Saturday, April 21, 2018, the weather was excellent as approximately 60 members and guests of the Arizona Geological Society visited Freeport-McMoRan's United Verde volcanogenic massive sulfide deposit, located in Jerome, Arizona.   Participants included a number of professionals; both active and retired, as well as university facility and students.

Participants listen to Presentation on the History of the Verde Mining District

Following a brief orientation by our hosts, David Briggs gave a brief presentation on the history of the Verde mining district from an elevated area near the General Office, where attendees could view many of the important historical landmarks in and around the United Verde pit.   For those who wish  to learn more about Jerome, a comprehensive article on the history of the Verde Mining District, can be downloaded from the Arizona Geological Survey's web site.

Paul Lindberg Presentation at United Verde Pit Overlook

Participants hiked from the General Office to an overlook at the United Verde open pit, where Paul Lindberg discussed the volcanogenic massive sulfide model that describes how the United Verde ore deposit formed.  He also employed a block model to describe the structural evolution of the Verde mining district and its impact on the development of supergene enriched zones at the United Verde and United Verde Extension deposits.

Dave Briggs presents Honorary Life Membership to Paul Lindberg

At the conclusion of Paul's presentation, the Arizona Geological Society awarded Paul with a Honorary Life Membership in recognition of his exceptional contributions to Arizona Geology over nearly five decades.

Particpants Enjoy Lunch at United Verde Pit Overlook

The field trip participants enjoyed lunch at the overlook of the open pit, where many examined the altered Cleopatra Rhyolite in the footwall of the massive sulfide ore body and collected representative samples.

Jerry Waegli and Ralph Stegen Discuss Geology of the United Verde Ore Body

After lunch, participants hiked back to the General Office, where Jerry Waegli and Barbara Neilsen made their presentations.  Jerry Waegli discussed various aspects of the United Verde massive sulfide ore body and various exploration programs that have occurred since the mine's closure in 1953, while an interesting presentation on Freeport-McMoRan's reclamation activities in the district was made by Barbara Neilsen. 

Museum at Jerome State Historic Park

The formal field trip ended around 1:30 PM, giving those participants who wished learn more about the area an opportunity to visit the museum at the Jerome State Historic Park and the Jerome community.

2018 Spring Field Trip Acknowledgements

The success of our 2018 Spring Field trip to Jerome on Saturday, April 21, 2018, would not have been possible without the volunteers, resources and assistance provided by Freeport-McMoRan, Inc.  The Arizona Geological Society is grateful for their generous support.

Any successful event of this type, requires a lot of hard work and planning by many individuals.  The Arizona Geological Society applauds Ralph Stegen, Jerry Waegli, Barbara Neilsen, Paul Lindberg and David Briggs for their excellent job of planning and leading this event as well as preparing an excellent field trip guidebook for its participants.

Freeport-McMoRan personnel, who volunteered their time to help out with field trip logistics included: Duff Sorells, Robert Miller, Eric Lorret, Bruce Crane and Stan Walkup.  Chief Rusty Blair of the Jerome Fire Department also helped make the outing safe for all participants.

The Arizona Geological Society thanks everyone, who helped make our 2018 Spring Field Trip a success.

AGS Digests Now Available On-line

Articles contained within the Arizona Geological Society Digests 1 through 22 are now available on-line at our publications page.  Our out-of-print Digests are available to the public, While our in-print Digests are only accessible to AGS members. 

Anyone who is interested in purchasing Printed Copies of In-Print AGS Digests can do so on-line or contact the AGS Secretary for more details.  Copies of current AGS Guidebooks and Digests are also for sale at a reduced price at AGS monthly dinner meetings.

Copyright © 2013 Arizona Geological Society
Powered by Wild Apricot Membership Software