2021 Mining and Mineral Symposium

September 9-11, 2021

Butte, Montana (Announcement)

Join professional and amateur mineralogists, geologists, and miners as they share their knowledge of mineral deposits and stimulate interest in pursuing new studies and discoveries.The Montana Bureau of Mines and Geology is pleased to host the 6th Annual Montana Mining and Mineral Symposium on September 9–11, 2021 at Montana Tech, located in historic uptown Butte, Montana.



See you next year!


2021 Brochure — Download the PDF


2019 Proceedings
2018 Proceedings


2019 Symposium

Submit an abstract, extended abstract, or short paper to:
Email K Scarberrykscarberry@mtech.edu or Email skorzeb@mtech.eduskorzeb@mtech.edu


Symposium registration:
Early registration: $75
Registration after 8/7/2021: $100
Zoom Registration: $50
Speakers: $50
Field Trip: $25
Students (with ID): FREE (Must Register) or (Must Register by Download)

Cancellations/Changes and Refunds: Fees for late arrivals and early departures will not be refunded. Fees will be refunded if requests to cancel or change a registration are received no later than August 7, 2021. After that date, fees are nonrefundable. The MBMG will process all refunds after the Symposium’s conclusion.


Thursday, September 9th, 2021
Oral presentations (including lunch) will be followed by an evening Poster Session at Montana Tech, with hors d’oeuvres and a no-host bar.

Friday, September 10th, 2021
Enjoy oral presentations (including lunch) and lab tours followed by an evening Map Chat at the Butte Brewery. Enjoy great beers and pizza from the Butte Brewing Company, meet our MBMG geologists, and learn about their current mapping projects. Bring your mineral samples and try to stump our geologists!

Saturday, September 11th, 2021
Field Trip: An all-day field trip (lunch provided) will visit Montana Tunnels Mine and Mill and the Elkhorn Mining District.

Informal Meet & Greet at the Butte Brewery after the field trip, with a no-host bar.



Thursday, September 9th (2021): 9 AM to Noon: 1 – 4 PM

9:00 a.m.– 9:05 a.m. Opening Remarks – John Metesh, MBMG’s Director and State Geologist.
9:05 a.m. – 10:05 a.m KEYNOTE: An update on hard rock mining in Montana, Garrett Smith.
10:05 a.m. – 10:35 a.m. The history of the School of Mines at the College of Montana in Deer Lodge, the first school of mines in the Montana territory and state, Millbrooke,Anne.
10:35 a.m. – 10:45 a.m. Coffee Break
10:45 a.m.– 11:15 a.m. The lack of government assistance to exploration and mining in the U.S. with those active programs of Canada and Australia, Dawson,Patrick.
11:15 a.m.– 11:45 a.m. Interrelationships of Porphyry Copper, Iron Oxide-Copper-Gold, and Sediment-Hosted Ore Deposits Within the CO2/CH4-H2S Framework: A Fluid Mixing Model Including Sedimentary Hydrocarbons and Brines and its Use in Exploration for Deep Sediment-Hosted Porphyry Cu Deposits at the Clementine Prospect, Brimhall, George.
11:45 a.m.– 12:15 p.m. Mining History and Mineralogy of the Black Pine Mine, Granite County, Montana, Gobla,Mike.
12:15 p.m. - 1:15 p.m. Lunch
1:15 p.m. – 1:45 p.m. Depth of emplacement of the Boulder batholith, and implications for Laramide tectonic shortening and exhumation,Dilles,John and Scarberry,Kaleb C.
1:45 p.m – 2:15 p.m. SHRIMP U-Pb ages and geologic relations among Boulder batholith plutons, selected satellite plutons, and Elkhorn Mountains Volcanics, western Montana, Lund,Karen.
2:15 p.m. – 2:45 p.m. Structural analysis reveals wrench-fault controls of vein systems and new ore Resource in the Radersburg District, Byington,Craig B.
2:45 p.m. - 2:55 p.m. Coffee Break
2:55 p.m. – 3:25 p.m. New Investigations of Mineral Resources in the Elkhorn 7.5' Quadrangle, Korzeb,Stanley L.
3:25 p.m. – 3:55 p.m. A New Look at the Sapphire-Bearing Yogo Lamprophyre Dike, MT Ridley,John.
3:55 p.m. – 4:25 p.m. Production history, structural controls and renewed exploration of mesothermal silver-base metal veins in the East Coeur d' Alene Mining District, Mineral County, Montana, Cox,Bruce and Antonioli,Ted.
4:25 p.m. – 4:45 p.m. Remote sensing exploration and assessment of rare earth element occurrences, Sheep Creek, Montana, George,Allen.

Thursday, September 9th (2021): 5 PM to 8 PM - MTech; Big Butte Room; no-host bar

Mineralogy, stable isotope, and fluid inclusion study of the polymetallic porphyry(?)-lode deposits of Philipsburg, Montana,Beaucamp, Celine.
Structural analysis reveals wrench-fault controls of vein systems and new ore Resource in the Radersburg District,Byington, Craig B.
Geohazards of Jefferson County, MT,Gavillot, Yann
Skarn mineralization, geology and geochemical exploration: JWD lodes Jefferson County, Montana, USA Boulder Mining District,Gruber, J. and Dawson, Patrick.
Geology and an update on mining activity at the Lucky Friday Mine, Idaho,Redgrave, M.
USGS Earth-MRI critical minerals program mapping/materials. Update on Elkhorn 7.5’ mapping (field sheets + sketch strat column),Scarberry, Kaleb C.
Recent earthquake clusters in Stanley, ID, Stickney, Mike
Lithogeochemical Evaluation of Hydrothermal Alteration in the Scatter Creek Formation,Ferry Co., WAStanfield, John.
The fate of barium in a geothermal area, Yellowstone National Park,Zimmerman, Jarred.

Friday, September 10th (2021): 9 AM to Noon: 1 – 3 PM

9:00 a.m.– 9:10 a.m. Opening Remarks – Gammons,Chris
9:10 a.m. – 10:10 a.m KEYNOTE:The Stillwater Complex, a Review, Alan Boudreau
10:10 a.m. – 10:40 a.m. Rattlesnake Hills Alkaline Complex, Wyoming: Igneous and Hydrothermal EvolutionRunyon, Simone.
10:40 a.m. – 10:50 a.m. Coffee Break
10:50 a.m.– 11:20 a.m. Stable Isotope Applications to the Architecture of Magmatic-Hydrothermal System,Larson, P.
11:20 a.m.– 11:50 a.m. A review (with new data) of the stable isotope signatures of sulfide and sulfate minerals from metallic mineral deposits of Montana,,Gammons, Chris
11:50 a.m.– 12:20 a.m. Mineralogy, stable isotope, and fluid inclusion study of the polymetallic porphyry(?)-lode deposits of Philipsburg, Montana, Beaucamp, Celine.
12:20 p.m. - 1:20 p.m. Lunch
1:20 p.m. – 1:50 p.m. Mineralogy and fluid inclusion study of the Margret Ann mine; a gold-rich vein on the northern edge of the Butte district, Ostenburg,Tiffany.
1:50 p.m – 2:20 p.m. New investigations of the geology and geochemistry of the Mesoproterozoic Black Butte Cu-rich massive sulfides, central Montana, with an emphasis on the Lowry deposit. Allard,John
2:20 p.m – 2:50 p.m. Geochemistry of Naturally-Occurring Acid Rock Drainage in the Judith Mountains, Montana: A Synoptic Study of Chicago Gulch, Edinberg,Sara.
2:50 a.m. – 3:00 a.m. Coffee Break
3:00 p.m. – 3:30 p.m. Mining in the western Washington Cascade Mountains, Cangelosi,Gabe.
3:30 p.m. – 4:00 p.m. Resource Development of Silver-Zinc Veins Within the Rainbow Block,Butte MT, Harvey,Dave.
4:00 p.m. – 4:20 p.m. MBMG’s active role in preserving, describing and re-examining mineral resources In Montana, Metesh,John.
4:20 p.m. – 4:40 p.m. 2021 Uno Sahinen award”: Closing remarks and invite to the brewery, Metesh,John.

Social: Fri., Sept. 10th, 5 PM – 8 PM (Butte Brewing Co.)

5 PM – 8 PM MBMG invites symposium participants to the Butte Brewing Company for a lively night of fun and conversation. MBMG has the entire upstairs of the brewery on reserve and will provide the pizza. The social provides an opportunity to share ideas with like-minded people in a low-key environment in uptown Butte.

Field Trip: Sat. Sept. 11th, 8:30 AM – 6 PM: Montana Tunnels to Elkhorn

6:00 p.m. The field trip will depart the Natural Resources Building (home of the MBMG) at 8:30 AM and travel to Montana Tunnels, then to Elkhorn ghost town for lunch. At Elkhorn we will visit the old mine and collect sphalerite on the dumps, check out the skarn minerals and then head east up Queen gulch to look at the Turnley Ridge quartz-eye porphyry (time depending). MBMG will provide box lunches and drinks. Space is limited to 30 participants so register early!


Thursday morning:

John Metesh

MBMG’s Director and the State Geologist of Montana. John has a strong understanding of Montana’s groundwater, abandoned mine lands and the interaction between the two in Montana.

Garrett Smith

Garrett Smith is a geochemist, currently working for the Montana DEQ’s Hard Rock Mining Section in Helena. Originally from New Mexico, he returned to his ancestral roots in Montana to complete his undergraduate and graduate degrees at Montana Tech. With an early emphasis on stable isotope geochemistry, his project experience includes the hydrogeology of abandoned and active mines, characterization of geothermal systems, hard rock mine permitting, and public outreach. Prior to his current position, Garrett was an assistant research professor with the Montana Bureau of Mines and Geology in Butte.

Anne Millbrooke

Anne is a historian that grew up in western Washington. She earned a doctorate in the history of science from the University of Pennsylvania and has taught history courses. She history at universities in Alaska, Connecticut, and Montana. Anne’s recent work has focused on the J.T. Pardee, the famous USGS geologist born in Phillipsburg, and the history of mining in Montana.

Patrick Dawson

Patrick Dawson, a former underground miner at the Mountain Con Mine in Butte, is currently conducting exploration on several lode claims in Jefferson County. He worked a few years as State Reporter for the Billings Gazette before performing assignments in the Rocky Mountain West for TIME Magazine for 30 years. He is author of two non-fiction books.

George Brimhall

George was the Steward Mine Geologist for the Anaconda Company following his doctoral research on the deep copper-molybdenum deposit running east-west across the Butte District. Starting 1974 as Project Geologist, he led the exploration fan drilling from the underground from a newly-driven cross-cut from the Steward to the Belmont Shaft on the 3400 level. This work defined the early-stage copper, molybdenum, and magnetite zoning and created the first ore reserve for the western 1/3 of the Butte District expanded later by Arco through surface drilling. From Butte, he worked at the Johns Hopkins University for two years and then became the professor of economic geology at the University of California, Berkeley for 32 years where his field work took him across the US, to Africa, Australia, New Guinea, Chile, Argentina, Bolivia, Russia, and Mongolia. In 2011 he retired from academia and set up Clementine Exploration to explore for new deep copper deposits in southwest Montana amenable to underground mining with a small environmental footprint. This meant improving understanding of the tops of porphyry copper deposits that are not as well exposed as former systems and exhibit new geological features. Throughout his career Brimhall has enjoyed teaching undergraduates field geology and current global earth resource issues in society.

Mike Gobla

Mr. Gobla is a geotechnical engineer with the Bureau of Reclamation in Denver, Colorado. He has degrees in mining engineering from the Colorado School of Mines and New Mexico Tech. His professional accomplishments include the design of major mine reclamation projects including the Summitville Mine in Colorado and the Gilt Edge Mine in South Dakota. For the past 40 years, Mike has been a mineral collector specializing in Montana mineralogy and mining history.

Thursday afternoon:

John Dilles

John is wrapping up his career as a Professor at Oregon State University. He is a specialist in the Geology and geochemistry of mineral deposits, and field geology and has worked all over the North American Cordillera

Karen Lund

Karen is a senior research geologist with the U.S. Geological Survey in Boulder, CO. Karen specializes in the regional tectonic setting of ore deposits and has spent considerable time examining the Boulder Batholith – Elkhorn Mountains magma system.

Craig B. Byington

Craig received a B. Sc. in Geology from Idaho State U. and a M. Sc. in Petroleum Geology from California State U. He is a (NI 43-101) Qualified Person in geotechnical engineering and economic geology, a Registered Professional Geologist (Idaho) and a Full Member in SME. He owns and manages Millennium GeoScience consulting, Holistic Mines Group and Crow Creek Mining company. He served as Montana Tech’s Assistant Dean, School of Mines and Engineering and taught at Colorado Mountain College. While working in eight countries, he pioneered and authored the techniques of Integrated Structural Analysis (ISA) and Stress-field Orientation Mapping and Analysis (SOMA), and has written papers, made formal presentations and taught professional seminars regarding structural geology, geotechnical engineering and economic geology in venues ranging from California to West Virginia and from northern Canada to Argentina. He supervised and participated in mine-development and exploration projects in Argentina, Bolivia, Canada, Columbia, Honduras, Mexico, Nicaragua, Panama, and many locations in the United States. His responsibilities included in-mine production and development geology, district and regional exploration, development miner, slope-stability analysis and design, spoils pile failure analysis, electronic and pyrotechnic blast-vibration control, slope stability monitoring, rock-mechanics modeling, structural training, ore-reserve analysis, surface- and underground-mine engineering design, geotechnical domain analysis, geological mapping, geochemical sampling, and drill-project supervision. In addition to many consulting venues he served as Sr. Geotechnical Engineer with Rio Tinto Energy America in Wyoming responsible for oversight of seven, open-cut, coal pits at three mine sites; as Sr. Geotechnical Engineer with Newmont Mining Company in Nevada responsible for slope-stability design and modeling, blast modeling, and geotechnical monitoring and failure remediation for all open-pits, rock-mass storage facilities, and water-storage impoundments at the Lone Tree, Phoenix and Mule Canyon mines; as Sr. Structural Geologist with Virginia’s Department of Mines, Minerals and Energy in Virginia responsible for developing and implementing geotechnical engineering solutions for safety, productivity and profitability for all mines in the State of Virginia; as President of MexGold, Inc. in Jalisco, Mexico responsible for corporate business development and organizing an international geologic and engineering staff; as Regional Exploration Manager - Latin America and acting Vice President, Exploration for Greenstone Resources in Nicaragua responsible for supervising exploration projects in three foreign countries; as Sr. Exploration Geologist for Freeport Gold, Inc. in Montana responsible for all aspects of exploration in Idaho, Washington, Oregon and Alaska; as Project Manager for Cypress Minerals, Inc. in Southeastern California; as President for Equity Resources in Idaho; as Sr. Exploration Geologist and Project Manager for Homestake Mining Company in Colorado responsible for multi-stage exploration and development projects; as Sr. Exploration Geologist and Project Manager for Homestake’s Mine Development group in Nevada; as Production Geologist, Chief Mine Geologist and District Exploration Geologist for ASARCO, Inc. in Colorado and Idaho responsible for production, development, diamond-core drilling and exploration in the Galena Mine and Black Cloud mines.

Stanley L. Korzeb

Stan is currently MBMG’s economic geologist and an expert in mineralogy and field description of ore deposits. Stan has over thirty years of experience related to mineral resources world-wide, including a fifteen-year stint with the U.S. Bureau of Mines and Geology and another fifteen years working in industry.

John Ridley

John is an economic geology professor at Colorado State University in Fort Collins, CO where he teaches field methods and field geology (amongst other courses). John’s research interests center around the large-scale controls on the chemistry and migration of hydrothermal fluids in the crust as they relate to ore deposits. John has written a book titled, “Ore Deposit Geology” that was published by Cambridge University Press in 2013.

Bruce Cox

Bruce Cox is a geological consultant wearing many hats. His work is focused on mineral exploration and mine geology, surface and underground geologic mapping, ore deposit structural controls, project generation and permitting. He has been collecting fluorescent minerals since the 1950s.

Ted Antonioli

Ted Antonioli is an exploration geologist focused on ore deposits in Western Montana and a little bit of Idaho.

Chris Gammons

Chris Gammons is a Professor in the Geological Engineering Department at Montana Tech. He earned his B.Sc. in Geology from Bates College in 1980 and his Ph.D. in Geochemistry and Mineralogy from Penn State University in 1988. His research focuses on Aqueous geochemistry at high and low temperatures, economic geology, acid mine drainage, and stable isotopes.

George Allen

George Allen is a Montana Tech student and a candidate for the Interdisciplinary Master of Science degree. He has a bachelor’s and a master’s degree in Geology from Baylor University. As a photogeologist, structural geologist, and seismic interpreter, George has integrated near-surface and deep subsurface control in the Upper Magdalena and Llanos basins (Colombia); southern Oklahoma and Texas; the Canadian Rockies, Northwest and Yukon territories; the Lusitanian Basin (Portugal); and offshore Nigeria. George has worked for major energy companies for most of his career. Although satellite-to-ground-truth rare earth element exploration is his technical focus, his greater interest is in seeing the Montana Tech community influence world energy transitions. Home is Calgary.

Friday Morning:

Alan Boudreau

Alan Boudreau is an emeritus professor at Duke University, where he had a faculty position from 1989 to 2012, as well as an adjunct professor at the University of North Carolina Chapel Hill. He received a B.A. in Geology from Berkeley in 1976, an M.S. in Geology from the University of Oregon in 1982, and a Ph.D. from the University of Washington in 1986. His Ph.D. thesis was on the role of fluids in the genesis of PGE mineralization in the Stillwater Complex, Montana. Throughout his academic career, Alan’s main research interests have focused on the origin of layered igneous intrusions and their contained mineral deposits.

Simone Runyon

Simone Runyon attended the University of Arizona for her MS work, where she focused on Fe-oxide rich mineralization in the Yerington district, Nevada, and her PhD, where she worked on deep forms of hydrothermal alteration in porphyry Cu deposits in Arizona. After spending about a year as a postdoctoral researcher at the Carnegie Geophysical Lab, she started at the University of Wyoming as an Assistant Professor in Economic Geology. Since starting at Wyoming, she has begun projects investigating hydrothermal alteration and mineralization in a variety of deposits across the state.

Peter Larson

Peter Larson was born and raised in the middle of Michigan’s Upper Peninsula native copper mining district. His interest at an early age in the mining geology of the area prompted him to declare his major in Geology five minutes after enrolling as a freshman at Michigan Tech. After several years of experience in metals exploration in the upper Midwest and in the West, he completed his PhD at Caltech and then served on the Geology faculty at Washington State University for 38 years, where he applied stable isotope analyses to understanding water-rock interaction in hydrothermal environments. He retired this past May and is still active in hydrothermal research.

Chris Gammons

Chris is a Professor in the Geological Engineering Department at Montana Tech. He earned his B.Sc. in Geology from Bates College in 1980 and his Ph.D. in Geochemistry and Mineralogy from Penn State University in 1988. His research focuses on Aqueous geochemistry at high and low temperatures, economic geology, acid mine drainage, and stable isotopes.

Celine Beaucamp

Celine is a 2nd year Ph.D. student in Montana Tech’s new Earth Science and Engineering Program. She got her first degree in Geology and Environment at Chambery, France, and then moved to Montreal for her master's degree in Economic Geology. She has several years of experience as an open pit geologist and geotechnical engineer at the Cortez Barrick Gold mine in Nevada and teaching at the University of Montana Western in her present hometown, Dillon.

Friday afternoon:

Tiffany Ostenburg

Tiffany is a 2nd-year M.S. student at Montana Tech working under the tutelage of Dr. Gammons. Tiffany has worked at MBMG for over 3 years and is currently employed by the Earth-MRI program to examine MT abandoned mine lands and assess their potential for critical mineral resources.

John Allard

John is a 2nd-year M.S. student at Montana Tech and is advised by Dr. Gammons. He is from California, got his first degree at U-Montana Western, and has a passion for field geology and ore deposits. He spent the past two summers in Alaska bush camps.

Sara Edinberg

Sara is a new-hire at MBMG and is an Assistant Hydrogeologist with the Ground Water Assessment program. Prior to her move to MBMG, Sara was a star student in Dr. Scarberry’s Structural Geology class at Colorado State University, earned her M.S. from Montana Tech and advised by Dr. Gammons and also spent three plus years working for the DEQ in Helena.

Gabe Cangelosi

Gabe is a B.S. student in the Geologic Engineering Dept. at Montana Tech. Gabe spent last summer working alongside Stan Korzeb collecting rocks from old mines in the Elkhorn 7.5’ quadrangle for an Earth-MRI geologic mapping project. Gabe is most comfortable climbing into abandoned mines to look for “high-grade”.

Dave Harvey

Dave is the Exploration Manager of the Blackjack silver project in Butte, MT. Dave is a minerals geologist with a 35-year backdrop in exploration, mineral resource and mine reserve development. Served in roles as Senior Mine and Exploration Geologist, Chief Geologist, Exploration Manager, Director of Exploration and VP Exploration within the precious metal, base metal and industrial mineral sectors including various assignments with Echo Bay Mines, Coeur d’Alene Mines, Kinross Gold mining and several junior explorers.

John Metesh

MBMG’s Director and the State Geologist of Montana. John has a strong understanding of Montana’s groundwater, abandoned mine lands and the interaction between the two in Montana.


Stable Isotope Applications to the Architecture of Magmatic-Hydrothermal Systems
Peter B. Larson,School of the Environment,Washington State University

The convective circulation of heated water is a natural consequence of the emplacement of magmas into the intermediate and shallow crust. Interaction between these circulating fluids and their wall rocks produces distinctive patterns of hydrothermal alteration, and these environments host several important styles of hydrothermal mineralization. For examples, porphyry mineralization can form in the near-magmatic environment, and epithermal deposits are characteristic of the shallowest parts of these systems. Oxygen isotope analyses of the hydrothermally altered rocks can be applied as an important monitor of hydrothermal water-rock interaction, and they can provide a useful map of the scale of hydrothermal activity. Stable isotope analyses, coupled with mineralogic studies of the alteration, have been carried out at several large hydrothermal systems (both active and fossil) that are exposed at different erosional levels. These studies can be compiled to construct three dimensional pictures of magmatic-hydrothermal systems from deeper levels to the surface, with special emphasis on caldera-related hydrothermal systems.

The Rico, Colorado, hydrothermal system hosts a deep stockwork Mo deposit and shallower epithermal vein mineralization that produced rich Ag deposits. With deep drilling and steep mountainous topography, the hydrothermal system can be sampled over a vertical interval of nearly 4 km. Stable isotope analyses of the altered rocks show that the hydrothermal effects can be mapped in both host intrusive and sedimentary rocks for more than 5 km from the system’s center (Larson et al., 1994; Meuzelaar, 1996). Shallower examples of large hydrothermal systems that have been examined using stable isotopes include alteration around Eocene plutons in the Idaho batholith (Criss and Taylor, 1983), and 23 Ma hydrothermal system associated with the formation of the Lake City Caldera, Colorado (Larson and Taylor, 1986). In both cases, hydrothermal circulation was strongly controlled by permeable zones that include fractures associated with calderas. Finally, research on the active hydrothermal system at the Yellowstone Caldera provides important information about the shallowest part of large of hydrothermal systems (Larson et al., 2009; McMillan et al., 2018), where fluids rise along the hydrostatic boiling curve through permeable plumbing.

Compiling these examples yields some interesting features of the magmatic-hydrothermal environment. Even at the deeper levels near where magmas are emplaced (~4-6 km), hydrothermal effects can extend kilometers away from the driving heat source for the circulation. Porphyry style mineralization with potassic alteration and a strong magmatic fluid component can form in and around the intrusions. Distal alteration is dominated by ambient groundwater (meteoric in most cases) with a minimal magmatic component. Hydrothermal alteration in these areas is characteristically propylitic with chlorite, albite, calcite, and pyrite as important alteration products, among others. Fluids rise along permeable zones (e.g., fractures, permeable sedimentary units, flow contacts) and ultimately reach the surface where they boil upon rising. The boiling imparts a steep thermal gradient and the drop in temperature can produce drastic changes in fluid chemistry. The shallowest alteration is dominated by clays and can contain sulfate minerals.

An Update on Hard Rock Mining in Montana
Garrett Smith

This presentation will provide a summary of recent hard rock mining activity around the state and a brief overview about the types of mining projects that are permitted through Montana DEQ. Discussion will include the general duties of DEQ’s Hard Rock Mining Section and an update on current permitting actions for new operation applications and modifications to existing permits. The presentation will conclude with a photo tour of selected sites that represent the wide range of active operating permits that are inspected by DEQ staff. Site summaries may include a discussion of local geology and the associated commodities which contribute to the mineral wealth of the Treasure State.

The Stillwater Complex – A Review
Alan Boudreau, Duke University

Mineral deposits of the 2.7 Ga Stillwater Complex in South-Central Montana include modest resources of Ni-Cu disseminated to massive sulfides at the base of the complex, chromitite deposits of the Ultramafic series, the platinum-group element (PGE) deposit of the Johns-Manville (J-M) Reef, and a low grade Pt-Pd deposit known as the Picket Pin deposit, the latter two hosted in the Banded series. However, the only deposit to be commercially mined without government support is the J-M Reef. A review of the proposed models to explain the concentration mechanisms that formed these deposits range from orthomagmatic interpretations involving direct precipitation from a magma to suggestions that igneous hydrothermal fluids both introduced the ore components and modified the mineral assemblage at the magmatic stage.

Depth of emplacement of the Boulder batholith, and implications for Laramide tectonic shortening and exhumation
John Dilles* College of Earth, Ocean & Atmospheric Sciences, Oregon State University
Kaleb Scarberry, Montana Bureau of Mines & Geology, Montana Tech

The Boulder batholith of western Montana was emplaced between ~82 and 75 Ma lies principally in the hinterland or hanging wall of the Laramide fold and zone lying along the eastern Rocky Mountain front.

Here, we present hornblende barometry estimates of the pressure of crystallization Butte Granite unit of the Boulder Batholith, and granitic intrusions of the Pioneer batholith. This method yields estimates approximately 2 kb (corresponding to ~7 km depth) for samples collected from the northern Boulder Batholith (south and southeast of Helena) to the southern Boulder batholith (Butte to Whitehall), and the Pioneer batholith.

The Boulder Batholith in most cases intrudes along its roof the slightly older Elkhorn Mountains Volcanics (~86-82 Ma), which have described thicknesses of up to 3 km. Consequently, the depth estimates based on hornblende barometry differ greatly from the minimum stratigraphic depth of the roof. Folds and local thrust faults locally deform the Elkhorn Mountain Volcanics. In the Wolf Creek quadrangle north of Helena, The 80-74 Ma volcanic and volcaniclastic rocks of the Two Medicine Formation were thrust-imbricated and folded prior to deposition deposition of the Adel Mountain Volcanics 74.7 to 73.7 Ma, which are in turn cut by thrust faults.

A plausible explanation for the 7 km depth of emplacement of the upper part of the Boulder Batholith is that the batholith was emplaced into a thrust-imbricated, folded and thickened section of Elkhorn Volcanics. The timing of shortening must therefore be in a narrow time window between erupted of the Elkhorn Mountain Volcanics and emplacement of the Boulder Batholith.

Exhumation of the Boulder Bathoilth from ~7-9 km depth to ~2-5 km depth occurred in the Butte area between ~66 Ma and 62 Ma, and continued exhumation brought rocks to the surface prior to deposition of the base of the Lowland Creek Volcanics at ~52 Ma. These relationships suggest that Laramide shortening extended from ~80-75 Ma to <62 Ma, and but that exhumation was largely accomplished after Boulder Batholith magmatism largely ceased at ~75 Ma.

Mining History and Mineralogy of the Black Pine Mine, Granite County, Montana
Michael Gobla

Discovered in 1882, the Black Pine mine was developed into an important silver mine. The initial production was in November 1885 when 400 tons of ore were shipped to the Hope mill in Philipsburg. With the value of the mine demonstrated, the Black Pine Mining Company was incorporated in October of 1886. Although the Black Pine Mining Company failed, the mine went on to be successfully worked by the Combination Mining and Milling Company producing over 2 million ounces of silver. Subsequently, many other mining companies operated the mine that eventually produced a total of 5,622,000 ounces of silver, 3,000 ounces of gold, 10,678,000 pounds of copper, and small amounts of lead and zinc. Since 1900, the mine was noted for producing unusual minerals. In the 1980s many rare minerals were discovered at the mine. Mineralogists have continued to identify rare minerals in specimens preserved from this mine including three minerals that are new to science. Also, many of the rare minerals from the mine are well crystalized. The Black Pine mine is a world class mineral locality with a total of 79 different mineral species being confirmed from the deposit. This paper explores the mine history and the unique mineralogy of the Black Pine mine.

New investigations of mineral resources in the 7.5' Elkhorn Quadrangle
Stanley L. Korzeb

This presentation covers investigations of mineral resources in the 7.5' Elkhorn Quadrangle as part of the Earth MRI project funded by the USGS. Most mineral deposits occur in the Elkhorn mining district. Mineral deposit types consist of a porphyry system, breccia pipe, skarns, and carbonate replacements. The porphyry system was not developed into an operating mine because of low molybdenum grades. Most metal production was extracted from skarn and carbonate replacement deposits. The skarn deposits were explored for gold resources from 1980 to 2013. The last mine in the district was developed from 2011 to 2013 for a skarn hosted gold resource.

Interrelationships of Porphyry Copper, Iron Oxide-Copper-Gold, and Sediment-Hosted Ore Deposits Within the CO2/CH4-H2S Framework: A Fluid Mixing Model Including Sedimentary Hydrocarbons and Brines and its Use in Exploration for Deep Sediment-Hosted Porphyry Cu Deposits at the Clementine Prospect
George H Brimhall Clementine Exploration LLC, Wise River MT and
Kathy Ehrig,Australia

Magmatic-hydrothermal ore deposits including porphyry copper deposits (PC) and iron oxide copper gold (IOCG) deposits are often considered as unrelated types of crustal systems to sediment-hosted ores. This dissociation is due in part to lack of a comparative geochemical framework which depicts the composition of ore-forming fluids spanning both magmatic sources and hydrocarbon, brine, and meta-sedimentary fluids. Without understanding how magma and sediment-driven fluids may comingle, exploration for sediment-hosted PC deposits in the Sevier fold and thrust belt will remain poorly informed by science. Phase diagrams used to describe porphyry copper deposits cannot show hydrocarbon species as the common coordinate axis are sulfur and oxygen fugacity without any provision for organics, and hence are irrelevant to sediment-hosted ores. This dichotomy is in part a hard-rock versus soft-rock division in geology but it persists in professional specialization within industrial sectors of materials (metals and mining) versus energy (oil and gas) thus divorcing ore genesis from petroleum geology even splitting science from engineering. Today, clean sustainable green energy by decarbonization and electrification of the US economy requires transformative solutions without limitations imposed by historic subdivisions. Newly-mined critical and basic minerals-especially copper are needed to sustain production of electric vehicles, semi-conductor electronics, magnets, and lithium storage at an unprecedented level of demand.

Structural analysis reveals wrench-fault controls of vein systems and new ore Resource in the Radersburg District
C.B. Byington, R.P.G., P.E., Q.P.

The Radersburg (aka Cedar Plains or Crow Creek) mining district is located approximately 90 highway kilometers southeast of Helena, Montana. The district produced far in excess of the reported 10,109 kilograms of gold (325,000 oz.) with an average tenor of 26.4 g/tonne Au (0.77 opt Au), and is also credited with an additional 8,087 kilograms of silver (260,000 oz.) and small amounts of copper, lead and zinc production (Klepper, Rupell, Freeman and Weeks, 1971). The author entered the district in 2019 to find surprisingly encouraging economic geology characteristics, but no current activity by competitors. Subsequent reconnaissance visits confirmed the initial favorable impressions regarding the geological model, and eventually several lode claims were strategically staked after careful structural and satellite analysis. Ongoing work continues including geologic mapping of structure, petrology, alteration, sampling, and obtaining and evaluating public and private database resources.

The lack of government assistance to exploration and mining in the U.S. with those active programs of Canada and Australia
Patrick Dawson

This paper contrasts the lack of government assistance to exploration and mining in the U.S. with those active programs of Canada and Australia. It traces the origins and operations of the Department of Interior’s short-lived mission to assist prospectors and miners with mineral exploration and development after World War Two. Initially driven by the need to find strategic and critical materials and uranium to help power the new Atomic Age, the Defense Minerals Administration (DMA) was launched under authority of the Defense Minerals Production Act of 1950. Certain minerals, including asbestos, uranium, industrial diamonds, PGMs and iron ore were eligible for up to 90% federal participation.

A review of the sulfur isotope composition of metallic mineral deposits in Montana
Chris Gammons,Professor, Dept. of Geological Engineering,Montana Technological University

Montana contains a great variety of metallic mineral deposits that span a huge time range, from the Archean to the recent. Most of the major mines have been studied for many years, and quite a bit of data already exist on the stable-isotope composition of sulfur in the deposits. As well, the author and his students, in collaboration with Dr. Simon Poulson of the University of Nevada-Reno, have collected new S-isotope data on many deposits in western Montana. Some general trends based on a review of the published and unpublished data include the following:

  • The magmatic, Cu-Ni-Pt-Pd deposits of the Archean-aged Stillwater Complex have a tight cluster of 34S values near 0 ‰, consistent with a mantle origin of S. However, recent work by E. Ripley’s group using triple isotopes suggests that much of the S in the basal massive sulfides at Stillwater was assimilated from a country rock in the upper crust that also had 34S near 0 ‰.
  • Sediment-hosted Cu-Pb-Zn-Ag deposits in the Mesoproterozoic Belt Supergroup, including the Revett-hosted deposits of NW Montana as well as the SEDEX-style deposits of the lower Belt sequence, show a wide range in S-isotopes of pyrite and base metal sulfides with generally positive 34S values, consistent with derivation of sulfide-S from reduction of seawater sulfate.
  • Porphyry-lode deposits, including Butte and Heddleston, have a relatively restricted range in 34S clustering between 0 and +5 ‰, consistent with a mix of mantle S and “average sedimentary S” assimilated from the Belt Supergroup. Many other Ag-Pb-Zn deposits in central and western Montana, including Hecla, Philipsburg, Elkhorn, Emery, Barker-Hughesville, and Hog Heaven, have a range in S isotope values that is similar to that of Butte. One possible explanation is that, like Butte, most of these smaller Ag-Pb-Zn vein and carbonate-replacement deposits are related to porphyry systems.
  • The two largest epithermal gold mines in Montana, Golden Sunlight and Zortman-Landusky, show a wide range in 34S values, including some that are strongly depleted (34S < -5 ‰). A few other gold-rich deposits, including the Mayflower Mine near Cardwell, the Golden Messenger, York, and Miller mines of the Big Belt Mountains, as well as the lode mines of Virginia City, also have anomalously light S, between -5 to -20 ‰. The cause of this isotopic depletion in several of the richest lode-gold deposits and placer districts of Montana is an interesting question, but is not known at present. Some ideas will be presented.

The Fate of Ba in a Geothermal Area, Yellowstone National Park
Jarred Zimmermana and Peter B. Larson

The average crustal abundance of Ba is roughly 250 ppm (Hanor, 2000), however, the Yellowstone volcanic system has produced several units with concentrations of Ba well in excess of this. Whole-rock analyses of the Huckleberry Ridge Tuff Member C, Canyon flow, and tuff of Sulphur Creek all have Ba concentrations generally over 1 wt% (Pritchard and Larson, 2012; Larson et al., 2009). Of those three units, the tuff of Sulphur Creek (Tsc) was studied due to the exposure of hydrothermally altered rocks in the Grand Canyon of the Yellowstone River. Approximately 300 m of the Tsc has been exposed (Larson et al., 2009). Moreover, this section has also been pervasively altered by circumneutral and acid-sulfate fluids leading to pervasive argillic and locally advanced argillic alteration (Larson et al 2009). The relative uniformity of a single unit being altered allows for a study of the mobility and sequestration of Ba in such an environment. Most of Ba in the unaltered rock is concentrated in original magmatic K-feldspar phenocrysts, with minor amounts in magmatic oligoclase phenocrysts (Pritchard and Larson, 2012). Additionally, volcanic glass from the Tsc has up to twice the average crustal abundance of Ba (Pritchard and Larson, 2012). In the deepest exposed portions much of the original magmatic material has been replaced by illite, quartz, and, in upwelling areas, hydrothermal feldspars, including hyalophane ((K,Ba)(Al,Si)4O8) (Larson et al 2009). Hyalophane is the only Ba-bearing phase in this section, and for approximately 100 vertical m. While hyalophane does uptake a significant amount of Ba, some almost certainly escapes into the fluid and can be noted as elevated in thermal fluids from some circumneutral springs. Above the oxidation limit, where kaolinite becomes the dominant clay mineral, there are two Ba-bearing phases, baryte (BaSO4) and walthierite ((Ba.05Al3(SO4)2(OH)6), which are both commonly associated with vuggy silica. However, they are rarely found together. As H2S volatilizes from a boiling water table, it condenses and oxidizes while mixing with relatively pure, cool meteoric water, generating an acid-sulfate fluid (White et al., 1971; John et al., 2018). The acid-sulphate fluid attacks the rock, leaching any Ba still remaining in weakly altered rock before it is quickly precipitated as baryte or walthierite. While true paragenetic relationships have yet to be established, baryte is presumed to be an earlier phase associated with illite and Fe-sulfides from upwelling zones whereas walthierite crystallized in cooler portions associated with increased kaolinite content.

Argillic and localized advanced argillic alteration redistributed Ba concentrations in the Ba-rich tuff of Sulphur Creek (Tsc). In Seven Mile Hole, Yellowstone National Park, between Washburn Hot Springs and the Grand Canyon of the Yellowstone River, approximately 300 m of altered Tsc is exposed. The area has been altered by circumneutral fluids creating pervasive illite + quartz with hydrothermal feldspars in upwelling zones as well as acid-sulfate fluids generating pervasive kaolinite +/- sulfate. Acid-sulfate alteration is most pronounced at higher elevations and in the South Fork of Sulphur Creek, extending to the Grand Canyon where it can be found overprinting early circumneutral alteration. Circumneutral alteration is best seen 100 m below the current canyon rim on a topographic high between the canyon rim and Yellowstone River. This high is interpreted as a major upwelling zone with illite, quartz, and hydrothermal feldspar. Circumneutral fluids weakly altered the Tsc, occasionally leaving sanidine phenocrysts relatively unaltered. Replacing Ba-rich material with clay in reducing conditions, such as those in deep circumneutral conditions, keeps the Ba in the aqueous phase. As a result, it migrates into more permeable areas, like veins where conditions are feldspar-stable, evidenced by the various hydrothermal feldspars, notably hyalophane ((Ba0.5,K0.5)Al(Si,Al)3O8). Which hydrothermal feldspar is deposited likely depends on the cation ratios (K+/H+, Ba2+/2H+, etc.). Given the right conditions, hyalophane becomes the first sink for Ba and only sink in this regime. Higher up in the system conditions become more acidic and oxygenated leading to production of H2SO4, typical of acid-sulfate fluids. These conditions are likely exacerbated in the South Fork of Sulphur Creek due to the juxtaposition to the highly permeable caldera margin. As the boiling water table is lowered, the pervasive alteration from acidic fluids extends to greater depths. The acidic fluids more completely alter weakly altered rock, releasing much of the Ba remaining in sanidine. However, now there is abundant sulfate in the fluid and Ba is quickly sequestered as walthierite ((Ba0.5□0.5Al3(SO4)2(OH)6) and baryte. Walthierite is usually found with other alunite group minerals where, similarly to the hydrothermal feldspars, speciation is likely controlled by cation ratios. Pseudocubic habits indicate these alunite group minerals precipitated in steam-heated conditions potentially generated from a descending water table. Baryte is found in veins and veinlets near clusters of marcasite and pyrite but is seemingly paragenetically younger. Baryte and walthierite are typically found from the canyon rim to about 100 m below the rim with the most occurrences in vuggy silica in the South Fork of Sulphur Creek. However, walthierite was found on the topographic high with hydrothermal feldspars, potentially indicating waning fluid flow or perhaps deep oxidation to produce the necessary sulfate.

Some Hotel Price recommendations

LODGING DISCOUNTS are available September 8, 9, 10, and 11, 2021. There is a tentative concert (below), another symposium, and heavy summer travel expected so rooms will book quickly, so reserve early, and cancel if you decide not to physically attend. Blocked rooms need to be booked by August 31, 2021.

Comfort Inn – Call 406.494.8850 with Code MMS-YS14I9, $80+tax – K or 2Q, or online at https://www.choicehotels.com/reservations/groups/ys14i9?checkInDate=2021-09-08&checkOutDate=2021-09-12&ratePlanCode=BOPNTB

Copper King – Call 406.565.5001 with Code MMS, $119+tax – K or 2Q

Finlen – Call 406.723.5461 with Code MMS $94+tax
Historic Hotel Q (Only 3 rooms available)
Motor Inn Q or 2Q

Hampton Inn – Call 406.494.2250 with Code MMS, $96+tax – K or 2Q

Holiday Inn Express – Call 406.782.2000 with Code MONTANA TECH, average $130+tax (no block)

Quality Inn (previous War Bonnet) – SOLD OUT

FOREIGNER Concert, Butte Civic Center, 7:30 p.m., Saturday, 9/11/2021, call 406.497.6400, $32--$106 or at Tickets | FOREIGNER at Butte Civic Center, Butte, MT on 9/11/2021 7:30 pm | Butte-Silver Bow Civic Center

For a map of hotels and links to their websites, please click on the Trip Advisor link below.

Make reservations

Poster Session

Thursday, September 9th (2021): 5 PM to 8 PM - Tech/Copper Lounge

Mineralogy, stable isotope, and fluid inclusion study of the polymetallic porphyry(?)-lode deposits of Philipsburg, Montana, Beaucamp, C.
Structural analysis reveals wrench-fault controls of vein systems and new ore Resource in the Radersburg District,Byington, C.
Geohazards of Jefferson County, MT,,Gavillot, Y.
Skarn mineralization, geology and geochemical exploration: JWD lodes Jefferson County, Montana, USA Boulder Mining District,Gavillot, Y
Mineralogy and fluid inclusion study of the Marget Ann mine; a gold-rich vein on the northern edge of the Butte district.,Ostenburg, T.
USGS Earth-MRI critical minerals program mapping/materials. Update on Elkhorn 7.5’ mapping (field sheets + sketch strat column).,Scarberry, K.
Recent earthquake clusters in Stanley, ID.,Stickney, M.
Lithogeochemical Evaluation of Hydrothermal Alteration in the Scatter Creek Formation,Ferry Co., WA,Stanfield, J.
Geology and an update on mining activity at the Lucky Friday Mine, Idaho,Redgrave, Marisa.
The fate of barium in a geothermal area, Yellowstone National Park,Zimmerman, Jarred.

Special Events

SATURDAY September 11th - (All day) Montana Tunnels Mine & Mill and Elkhorn Mining District

Natural Resource Building

View of Elkhorn Peak

Natural Resource Building

Windy Point 4 - Elkhorn Field