Page 13 - 2020 GGE Newsletter

A NOTE FROM THE ECONOMIC GEOLOGY GROUP Page 13
CONT’D

Staff, Laboratory and Program Updates

Wendy Bohrson, our Geology Department head, is an igneous petrologist who joined the group in 2019. Wendy teaches Pe-
trology and Volcanology and is actively developing research programs and a research group.

Zhaoshan Chang resides in the Charles F. Fogarty endowed chair as a Professor of Economic Geology. He and his group work
to understand the formation process of mineral deposits, and develop exploration tools for skarn, porphyry, epithermal, Iron-
Oxide-Copper-Gold, and Tin-Tungsten deposits. His laboratory has one of the only laser ablation instruments coupled with a
triple quad (MS-MS) instrument which is capable of precise and sensitive analysis of minerals, single fluid composition analysis,
and U-Pb dating. The LA-ICP-MS laboratory has an ASI Resolution-SE ArF excimer 193 nm laser system and an Agilent 8900
ICP-MS/MS system. This instrument can analyze trace elements in minerals down to sub-ppb concentrations, provide mineral
mapping of trace elements (see Figure), and provide U-Pb dating of zircon, titanite, and other suitable minerals. The triple quad-
ruple setup allows separation of interfering masses through pre-filtering and mass shift. These open an entirely new field of min-
eral characterization and the ability to provide vectors and genetic information about mineral deposits. During 2020, the group
developed the mineral trace element mapping capacity. In-situ Rb-Sr dating and S isotope microanalysis methods are being de-
veloped. The group also utilizes infra-red spectral techniques.
Zhaoshan works closely with the mineral exploration industry looking for prospective and diagnostic mineral chemistry signa-
tures, minerals which either discriminate positive economic mineralization and/or provide zonation patterns capable of provid-
ing vectors to higher grade and fluid source direction within a deposit. The methods use mineralogy, texture, spectral features,
whole-rock chemistry, mineral chemistry, and/or unique isotopic characterization. The lab analyzes both internal and external
samples.
During 2020, Zhaoshan was the Society of Economic Geologists International Exchange Lecturer, giving talks about skarn zona-
tion patterns, lithocap characteristics and exploration, metal transport for high-sulfidation epithermal deposits, and mineral geo-
chemistry and application in exploration. Through the year, he has been invited to give presentations by numerous organizations
and conferences from 8 countries. Although it is not possible to travel due to the pandemic, Zhaoshan has delivered over 10
online presentations with ~2,000 global participants.
As the Director of the Professional Master’s in Mineral Exploration Degree program, Zhaoshan works closely with Mary Doherty
(PM program Manager) to try to make it possible for geologists to take the program without leaving their jobs. Zhaoshan contin-
ues serving as an Associate Editor for Economic Geology, Mineralium Deposita, and Acta Geologica Sinica (English Edition). He
is also an Adjunct Professor of James Cook University, Australia, a Guest Research Professor of the Institute of Geology, Chinese
Academy of Geological Sciences, the Chair of the IAGOD Working Group on Skarn Deposits, and a SEG Mentor.
Zhaoshan teaches GEGN401 Mineral De-
posits, GEGX571 Exploration Geochemistry,
GEOL508 Skarns and Related Deposits,
GEOL598 SWIR Spectral Analysis, and
GEOL520 New Developments in Mineral
Exploration. Two PhD students joined the
team in 2020 to develop new methods in-
cluding in-situ Rb-Sr dating, in-situ S iso-
tope analysis, and U-Pb dating of unconven-
tional minerals such as cassiterite, wolfram-
ite, apatite and titanite.

Figure 2: Exploration Geochemistry
students learn the intricate details of
Water Sampling Procedure, used for
Mineral Map showing element zonation within a garnet sample. Note enrich- both Environmental and Explora-
ment in La-Pr-Nd-Ho-Er-Y in the core, and outer zones relatively enriched in Al tion Geochemistry. U.S. Geological
-Sn-Ti. Data from Laser – ICP Triple Quad MS. Survey scientists Karen Kelley (left)
and Garth Graham (center) demon-
strate current practice and field
measurements.