2015 Issue 1 May 2015 AMERICAN INSTITUTE OF PROFESSIONAL GEOLOGISTS ARIZONA SECTION NEWSLETTER SECTION OFFICERS: J ULIE H AMILTON, CPG-09428 RICK SMITH, CPG-09794 DOUG B ARTLETT, CPG-08433 2015 PRESIDENT AMEC 1405 W. AUTO DRIVE TEMPE, AZ 85284 480-940-2320 Julie.Hamilton@amec.com CELL : 602-418-3950 2015 PRESIDENT ELECT AECOM 1860 E RIVER RD #300 TUCSON, AZ 85704 520-299-8700 Rick.Smith@aecom.com CELL: 520-850-2751 2015 PAST PRESIDENT CLEAR CREEK ASSOCIATES 6155 E. INDIAN SCHOOL RD., SUITE 200 SCOTTSDALE, AZ 85251 480-659-7131 Dbartlett @clearcreekassociates.com CELL : 602-762-0896 J AMES ADU, MEM-1311 GREG KINSALL, CPG-10643 2015 SECRETARY FREEPORT -MCMORAN SIERRITA OPERATIONS 6200 W. DUVAL MINE RD. GREEN VALLEY, AZ 85614 520-393-2669 James_Adu@fmi.com CELL : 520-419-5802 2015 TREASURER 744 E. W OOD DR. CHANDLER, AZ 85249 614-579-3330 gkinsall@gmail.com Arizona Section Spring Field Trip: Safford Mine On Saturday, April 18, the Arizona Section held its Spring field trip to the Freeport-McMoRan Safford Mine located about 8 miles north of Safford, Arizona. A total of 18 section members with friends and family participated in the event. Doug Bartlett gave a presentation on the geology of the area and the history of the mine development. In addition, there were five staff from the mine that helped guide us through the operation and its history. The mine is one of the few new large mining operations to open in recent years in Arizona. Permitting for the mine began in 1994. In 2003, the mine completed a land exchange with the BLM and the U.S. Army Corps of Engineers and in 2007 the Aquifer Protection Permit was issued by ADEQ. Full scale mining began in December 2007. Currently, the mine employs about 600 individuals. Ore is mined from two active open pits, the Dos Pobres pit and the San Juan pit. A total of about 100,000 metric tons per day is mined and then crushed/conveyed by overland conveyors to an agglomerator where the ore is wetted with a sulfuric acid solution before deposition on leach piles. The entire mine is designed to be zero discharging – the leach piles are lined and solutions report to lined ponds for processing through an onsite SX/EW. Numerous monitor wells are routinely sampled to assure that no leaks or releases occur to groundwater. The copper ore body was formed in the Paleocene after intrusion of quartz monzonite and granodiorite plutons into a Laramide-age andesite volcanic pile. The Laramide volcanics were then deeply eroded and supergene enrichment of the copper ore shells resulted. The Laramide andesites were covered with a thick sequence of basalt and andesite in the mid-Tertiary. Significant faulting occurred throughout the ore-forming and post-ore events with the most notable fault being the Butte Fault, a northwest trending normal fault downthrown to the southwest. The Butte Fault bisects the Dos Pobres ore body and has displaced and has displaced Electric shovel operating in the Dos Pobres open pit the southern half of it. (Continued on page 5 ) Inactive San Juan Open Pit Page 1 of 6 AZ Section February 14, General Meeting & Evening Social Event The Arizona Section held its annual meeting and social event which coincided with the AIPG National Executive Board meeting in Tucson on February 13-14, 2015. This also overlapped with the Tucson Gem and Mineral Show. The social event was held on Friday night, February 13 at La Cocina Restaurant. Members of the AIPG National Executive Board joined us for the evening and it was a success, seeing colleagues again and talking at the dinner table. On Saturday, February 14 we held our annual meeting at the Arizona Geological Survey office located at 416 W. Congress St., Suite 100, Tucson. During the meeting we reviewed the past year’s events, introduced the officers for 2015, and discussed plans for events in the coming year. Events to be undertaken are the Spring (to Safford Mine) and Fall field trips and student events at ASU in April with AEG and AHS. National Executive Board members updated us on AIPG events and plans including the Annual National Meeting in Anchorage Alaska in September; AIPG foundation activities; and various 2015 initiatives. An update from our State Geologist, Lee Allison, on the activities of the Arizona Geological Survey covered management of geo-database by the survey, ongoing research into the June 2014 earthquake near Duncan, and a bill to reopen the Mining and Mineral Museum and stewardship transferred from the Arizona Historical Society to the Survey. Attendees at the Annual AIPG Arizona Section Meeting Section and national officers giving talks Dr. Lee Allison (State Geologist) presenting an AZGS update Evening social at La Cocina Restaurant in downtown Tucson Page 2 of 6 Mark Your Calendars: November 7, 2015 Fall Field Trip We are working out the details for a fall field trip to be led by Paul Lindberg. The trip will be to the region south of Holbrook, Arizona where a very large area of land subsidence has resulted from solution of the Permian salt beds, creating the "Holbrook anticline". The field trip would be an all day, starting at the town of Snowflake, Arizona bright and early on Saturday morning. From Snowflake, the trip would head west on Highway 277 to the main attraction location called "The Sinks" where hundreds of sinkholes coalesce into one gigantic down-dropped area. The location can be seen on Google Earth near 34 degrees 33 minutes north and 110 degrees 16 minutes west. Before the land dropped by subsurface solution, the town of Snowflake would have been about a hundred feet higher. Once the subsidence took place over the past several million years the regional uniform surface gradient from the Mogollon Rim to the Little Colorado River to the north was compromised and once north flowing stream channels were down-dropped and local drainage reversals took place. Hiking will require sturdy boots and rigorous hiking over locally rough terrain although the distance traveled on foot is not more than a mile or so. This area truly needs to be seen to be believed. Once finished, the trip would proceed westward through the private ranch land and cross the subsidence basin and up to the top of the Holbrook anticline by car. From there, the group will take an easy walk to a valley overlook where hundreds of earth cracks in Coconino Sandstone can be observed. Continuing northwest, we will travel on dirt roads through a new solar wind farm to join Highway 377 leading from Holbrook southwest to the AlpineOvergaard, Arizona area. Participants will be on their own heading home from there with an option for dinner at the train station and a second night in Holbrook. Announcements Change at AIPG Headquarters Please be advised that Dr. Robert Stewart is no longer with AIPG headquarters. Recruitment efforts for the position of AIPG Executive Director are currently underway. Former AIPG Executive Director William Siok has agreed to come out of retirement to serve as Interim Executive Director until the search for a new AIPG Executive Director concludes. Information is available on the AIPG website. June 3rd: AIPG and AEG Meeting Joint meeting of AIPG and Association of Environmental and Engineering Geologists(AEG) Wednesday, June 3, 2015 in Phoenix, Arizona SunUp Brewing (5:30 PM to 9:00 PM) 322 E Camelback Rd, Phoenix Guest speaker will include Jeff Keaton on the topic of the Oso Landslide Come for a great presentation and to share some fun, food, and beer with your fellow geologists RSVP by May 27, 2015 to julie.hamilton@amecfw.com or call Julie at 602-418-3950 Page 3 of 6 Save the Date — June 26-27, 2015: CO Section-San Juan Mountains field trip The Colorado Section’s field trip will be in Ouray beginning with an “ice breaker” in the San Juan Room of the Community Center on Friday evening, June 26. Bob Larson, CPG and Ouray-based mining geologist, will present a power-point entitled San Juan Mining & Minerals. This will also introduce George Moore’s Guidebook to the geology and mining in the Ouray area. Copies of Moore’s book will be available for sale, along with a publication entitled “The San Juan Triangle of Colorado – Mountains of Minerals”. A Field Trip, Saturday the 27th, starting at Inspiration Point on Log Hill, and then travelling to Ouray, Highway 550 to Ironton Park, to the Idarado Overlook, and on up to the top of Red Mountain Pass to the Longfellow Mine; and then proceed back along the county road past the National Belle, Genessee-Vanderbelt, Guston, etc. On Sunday, people can explore on their own using George Moore’s guidebook. Options include either going up the Camp Bird road and possibly Yankee Boy Basin or driving over to Silverton to their museum, the Mayflower Mill and adjoining mines, or going up Molas Pass to look at the karst features in the Molas Lake Campground, Engineer Mountain, and surrounding features. Another possibility is hiking up the Bear Creek trail, just south of Ouray, to view an excellent exposure of the thinning of the Cutler Formation across the Box Canyon Fault, the quartzites and slates of the Uncompahgre Formation, and, after hiking up Bear Creek a bit, some excellent exposures of veins cutting through the San Juan Formation. Alternatives include going over to Telluride or going through Nucla and Naturita to the Dolores Canyon to Gateway and then through the Unaweep Canyon, a former path of the Colorado River before returning to Denver or wherever. Ouray and its hot-spring fed town swimming pool are great places for spouses and kids who are less interested in geology to spend time. A visit to the Box Canyon is a must. Those planning to attend should book room reservations at one of a wide variety of accommodations in Ouray that include campgrounds, motels, hotels, and condo rentals. Further details, including cost, whether there is interest in a trip from Denver to Ouray on Friday, will be forthcoming. Be sure to check the AIPG website for more details and contact information. Page 4 of 6 AZ Section Spring Field Trip: Safford continued from page1… The water supply for the mine is provided by several production wells drilled into what is termed “the Graben Aquifer”. This fractured bedrock aquifer is hosted in both Laramide-age andesite and mid-Tertiary basalt and andesite volcanic units. The aquifer is actually a large fracture zone just south of the Butte Fault that contains significant open fractures – enough to have provided all the mine’s water for the first 8 years of mine life. The mine will be moving a portion of water production to the “Lower Basin Fill” aquifer south of the mine. The LBF aquifer is hosted in alluvial sand and gravel deposits that flank the Gila Mountains. The LBF aquifer groundwater is of much poorer quality than the Graben Aquifer owing to the presence of evaporite deposits further south in the Safford Basin. Doug Bartlett introduces tour guides The tour group got an opportunity to travel to the bottom of the Dos Pobres open pit where we were able to see active mining through the operation of a large shovel filling haul trucks with ore. We then went to the currently inactive San Juan pit where a small lake has formed. Finally, we drove to the clay borrow pit used to provide clay for the leach pad liner where were able to see interesting soft sediment deformation in clay beds that formed originally when ancient Lake Graham existed in the Safford Valley (roughly 5 Ma to <2 Ma). Studies of the clay show that it has an extremely low permeability on the order of 10-9 cm/s. We thank our Freeport tour guides, in particular Betsy Crosby, Everett Brill, and Seth Henry for their patience and good nature and Claire Palmer and John Korolsky for making the tour possible and for enlightening us on the mine and its operations. An active open pit mine Our group photo – bottom of the Dos Pobres pit The stop for refreshment at the local bar in Safford Page 5 of 6 American Institute of Professional Geologists, Arizona Section Page 6 of 6
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