AIPG AZ Section May 2015 newletter.pub

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
[email protected]
CELL : 602-418-3950
2015 PRESIDENT ELECT
AECOM
1860 E RIVER RD #300
TUCSON, AZ 85704
520-299-8700
[email protected]
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
[email protected]
CELL : 520-419-5802
2015 TREASURER
744 E. W OOD DR.
CHANDLER, AZ 85249
614-579-3330
[email protected]
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 [email protected] 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