New Developments in the Geology and Exploration of Mineral Deposits

Note: We have five different categories of tickets for both the whole event and individual days depending on whether you are a Company Professional (CP); USGS Employee or DREGS Member; Mines Student (registered for 520); Mines Student (not registered for 520) or a Non-Mines Student. There are also in-person and online tickets. Please choose your ticket(s) appropriately.

I. Lithologic Settings and Geochemistry

a) Geochemistry of productive porphyries; b) Multi-phase intrusive activity; c) Hostrock and wallrock significance

II. Alteration Mineralogy and Geochemical Considerations

a) Alteration types and mineralogic importance: b) Paragenetic relationships and alteration mineral evolution

III. Mineralization

a) Styles and distribution: veins, veinlets, breccias; b) Ore mineral zoning and association with alteration assemblages; c) Paragenesis of ore and ore-related minerals; d) Transitional environments: Cordilleran veins, epithermal veins, replacement systems

IV. Metals Mobility in the Weathering Environment

a) Development of mature weathering profiles and geochemical stratigraphy; b) Surface geochemical environment; c) Supergene enrichment (Cu, Zn)

V. Exploration and Practical Applications Summary

a) Examples alteration-mineralization variations in porphyry systems

This course examines features of intrusion-related epithermal ore deposits in the epithermal environment, including the tops and bottoms of epithermal deposits and the transition to deeper porphyry deposits. The course will emphasize observations relevant to mineral exploration and assessment.

This course will provide a comprehensive overview on the geology of and exploration for orogenic gold deposits, the most widespread type of gold deposit globally and an important gold target type in Colombia. It will provide descriptions of the most important Precambrian and Phanerozoic examples of orogenic gold ores formed in the world’s young accretionary orogens and old cratonic greenstone belts. Topics to be covered include tectonic and structural controls, geological characteristics, geochemical and geophysical signatures, geochronological relationships, and exploration strategies. Other gold deposit types with some overlapping features, particularly intrusion-related and Carlin-type gold deposits, will be compared and contrasted to indicate what type of ore systems are the most favorable targets for the explorationist in various provinces.

Course Outline:

1) Introduction to the Geology of Gold Deposits

2) Geological Characteristics of Orogenic Gold (Gold in Metamorphic Rocks)

3) Mineralogy, Alteration, and Geochemistry of Orogenic Gold and Exploration Implications

4) Genetic Models for Orogenic Gold

5) Cenozoic-Mesozoic Orogenic Gold (and what about Colombia!)

6) Paleozoic-Neoproterozoic Orogenic Gold

7) Precambrian Orogenic Gold

8) Comparisons and Contrasts with Carlin-type Gold Deposits and Intrusion-Related Gold Deposits: Why the Confusion?

Skarns are one of the most common deposit types with significant economic values, and they are typically part of a larger magmatic hydrothermal system. Skarns may extend towards the causative intrusions to porphyry or greisen deposits depending on the redox state, and towards distal locations to carbonate replacement deposits, and farther away to Carlin- or Carlin-like deposits. For the exploration of skarn and related deposits, zoning is an effective tool. In addition, in skarn-porphyry districts there are typically many intrusions. To identify the causative intrusion, zoning is an important, sometimes the only tool. In this short course, recent discoveries in zoning patterns in both alteration and mineralization will be summarized and explained, after introducing the basic concepts of skarns (definition, classifications, terminology, and evolution stages).

Society has become dependent on technologies that rely on many minor elements that were once in low demand and hence in low production. The term “critical minerals”, coined in a 2008 National Research Council report, refers to minerals (or elements) that are essential and are at risk of supply disruption. Identifying potential sources for some of these elements deemed critical can be challenging. This course reviews the occurrence and genesis of critical elements in various ore deposit including critical elements as primary and by-product commodities.

This presentation will tell the story of silver production, from the Comstock to Caribou.

This course will present a global overview of sediment-hosted Zn-Pb-Ag ores from the syngenetic and diagenetic environments to high temperature burial and tectonic settings. The workshop will first consider Mississippi Valley-Type (MVT), evaporite-related ores and Clastic Dominated (CD) deposits (historically called SEDEX). Examples of deposits in the world's classic districts will be presented to illustrate the diversity of ore styles. The course will review the origin of the ore fluids, metal solubility and transport and precipitation mechanisms. Discussions on sediment-hosted Cu deposits will present their similarities and differences with Zn-Pb deposits. Understanding the geologic and tectonic controls on the distribution of these ores in the Earth’s crust through time gives insights into where and how sediment-hosted Zn-Pb-Ag deposits form and provide new exploration opportunities.

Submarine hydrothermal systems represent one of the oldest and most important ore-forming processes in the geologic record. This course will examine the diversity of hydrothermal systems and the nature of fluid flow in submarine volcanic environments, with an emphasis on the formation of volcanogenic massive sulfide deposits. The geological characteristics of these base and precious metal deposits and the hydrothermal processes that produce them will be discussed. Special emphasis will be placed on the interpretation of geological settings, controls on mineralization, ore mineralogy and geochemistry, hydrothermal alteration, and enrichment of precious metals. Strategies for exploration in ancient volcanic terrains will be derived

William X. Chávez, Jr. has been Professor of Geological Engineering and Economic Geologist at the New México School of Mines since 1985. He received B.S. degrees in Geology and in Mine Engineering from that school in 1977, and M.A. (1980) and PhD. (1984) degrees in Geology from the University of California, Berkeley.

Involved with ore targeting and interpretation of geochemical and geologic data, Dr. Chávez has worked with exploration companies in Latin America, Central Asia, western and southern Africa, Australia, and the U.S. The focus of Dr. Chávez’ studies and those of his students have been on porphyry, epithermal, and polymetallic vein-CRD systems.

William is an Honorary Lecturer with the Society of Economic Geologists, and has been the Thayer Lindsley Lecturer and the International Exchange Lecturer for the SEG; he continues to offer student- and professional-level workshops and field courses in mapping and in exploration geochemistry as a part of the Education and Training Committee of the SEG.

Antonio Arribas holds a BA and MSc in Geology from the Universidad de Salamanca and a PhD from the University of Michigan, followed by post-doctoral research with the Geological Survey of Japan. He has worked with the mineral exploration industry for over 20 years around the world, including Vice President Geoscience at BHP Minerals Exploration, Senior Manager Geosciences at Newmont, and Exploration Manager South America at Placer Dome. Dr. Arribas is now the Kenneth F. and Patricia Clark Distinguished Chair in Economic Geology at the University of Texas at El Paso. He is past President of the Society of Economic Geologists (SEG).

Richard J. Goldfarb received his BS in geology from Bucknell U., MSc in hydrogeology at University of Nevada-MacKay School of Mines, and his PhD in geology at the University of Colorado. He was a research geologist at the U.S. Geological Survey for 36 years. His studies have focused on global metallogeny, geology of ore deposits in the North American Cordillera with emphasis on orogenic gold, lode gold deposits in China, and geochemical applications to the understanding of ore genesis. Rich has authored more than 250 papers on mineral resources, which have received more than 15,000 citations, with many recognized as the authoritative research work on gold in metamorphic terranes and on aspects of regional metallogeny. He is a past-president of the Society of Economic Geologists (SEG) and past chief editor of Mineralium Deposita. He was awarded the Silver Medal by the Society of Economic Geologists in 2011 and the Gold Medal by the Society for Geology Applied to Mineral Deposits (SGA) in 2021 for his contributions to economic geology. Presently, Rich is a volunteer research professor at Colorado School of Mines and an overseas professor for China University of Geosciences Beijing, serves on the Board of C2C Gold Corp, and is an independent consultant to the exploration and mining industry.

Zhaoshan Chang is the Charles Fogarty Endowed Chair and Professor in Economic Geology at Colorado School of Mines (CSM), Golden, Colorado. Zhaoshan has studied several types of deposits, including skarn, porphyry, epithermal, IOCG, W-Sn, and sediment-hosted gold deposits, in 14 countries. He works closely with the industry on exploration-oriented research projects, looking for far-field signals, discriminators, and zoning patterns in mineralogy, textures, SWIR spectral features, whole-rock and mineral geochemistry, and isotopic compositions that can be directly used in exploration. He also works on ore-forming processes, magma fertility, regional metallogenesis, and SWIR spectral and LA-ICP-MS/MS techniques (mineral trace element analysis and mapping; dating). Zhaoshan has worked in five universities in three countries: Peking University, China (1997-2000), Washington State University, USA (2004), University of Tasmania (2004-2011) and James Cook University (2011-2018; EGRU Director), Australia, and Colorado School of Mines, USA (2018 - ).

Philip Verplanck is a research geologist with the Mineral Resources Program of the US Geological Survey. He received his B.S degree in geology from Tufts University, M.S. degree in geology from Oregon State University, and Ph.D. in geology from the University of Colorado. He has been with the U.S. Geological Survey since 1997. He has studied rare earth elements since 1983, and his REE research includes lunar evolution, igneous petrology, aqueous geochemistry, and ore genesis. Currently, his work focuses on ore-grade enrichment of rare earth elements in carbonatite and alkaline intrusive-related deposits and occurrences of critical elements in plutonic and volcanic systems.

David Leach received his B.S. degree at the Virginia Polytechnic Institute and his Ph.D. (1973) from the University of Missouri. He worked for the Lawrence Livermore National Laboratory for 5 years as a project scientist on uranium geochemistry, hydrothermal alteration experiments and exploration geochemistry. David joined the U.S. Geological Survey in 1978, where he worked for more than 34 years. He held a High Level CNRS Visiting Scientist at the University of Paris VI and Gledden Research Fellow at the University of Western Australia. He is currently a Research Professor at the Colorado School of Mines and Guest Professor at China University of Geoscience and consultant to the minerals industry. His career focused on hydrothermal mineral-rock interactions with special interest in sediment-hosted base metal deposits, ore formation in metamorphic environments, global metallogeny and exploration targeting. He is currently working on the connections between evaporites and sediment-hosted base-metal deposits with a focus on Asia, North Africa and the Americas.

Thomas Monecke is an economic geologist who specializes in the formation of base and precious metal deposits in modern and ancient volcanic arcs. He has more than 25 years experience in geological research and mineral exploration and has authored or co-authored approximately 80 journal papers, book chapters, government publications, and field guides during that period. Thomas graduated from the University of Freiberg, Germany, with a M.Sc. in 1996. He obtained his Ph.D. from the same university with his doctoral thesis focusing on the anatomy of a volcanic-hosted massive sulfide deposit in northern Australia. Between 2002 and 2008, Thomas conducted post-doctoral research at the Institute of Marine Sciences in Kiel, Germany, the University of Ottawa, and the Geological Survey of Canada on modern and ancient gold-rich volcanic-hydrothermal systems. In 2006, Thomas received the Waldemar Lindgren Award of the Society of Economic Geologists. He joined the Colorado School of Mines in 2008 where he currently teaches economic geology. Thomas runs a large research group and supervises graduate student working on a diverse range of hydrothermal ore deposits around the world.

Event Venue & Nearby Stays

Colorado School of Mines, Berthoud Hall - Room 241, Golden, United States