Van Tuyl Lecture: Anne Thompson, PetraScience Consultants

Anne Thompson, PetraScience Consultants

Berthoud 241/ Zoom, Thursday, November 3, 2022

Alteration Mineralogy – The Full Spectrum

Abstract: Alteration mineralogy is key to understanding the evolution of fluids and mineralizing processes important in the formation of ore deposits. Fundamental to our knowledge base is both the identification of individual minerals and the documentation of their relationships through space and time. Since conventional mapping tools may not identify fine-grained minerals or define important compositional variations, field spectroscopy became an extremely valuable technology for mapping alteration minerals.  The results are easily integrated into system and deposit models and may be associated directly with whole rock geochemistry.

We will examine how this data is collected by exploration and mining companies as well as how many academic groups integrate field spectroscopy into their studies.  There are several key considerations for both types of work, including which instruments are used, and how data is collected and processed.  Despite all the advances in systems over the last 25 years there are many points along the way where errors may be introduced into the results. Smart use of spectroscopy can be powerful, but poor interpretation or inadequate data will lead to loss of important knowledge.

A review of the science behind the spectroscopy as well as the current instrumentation and implementation leads us to several questions.  What is the current state of field spectroscopy?  Are there key areas of research that need to be addressed?  Clearly exploration and mining groups are acquiring vast quantities of analyses, but how good is the data and which approaches work best?  We will discuss these questions by examining case studies, reviewing the fundamental science, and considering current data analysis.

Biography: Anne Thompson is the producer and host of the SEG Discovery to Recovery Podcast and author of Innovation in Mineral Exploration published by PDAC (2020).  She has thirty-five years’ experience working in and consulting to the mineral exploration industry, including field work and applied mineralogy.  She was an early adopter of field spectroscopy and co-edited the Atlas of Alteration, a resource for exploration geologists.  Anne’s company, PetraScience, a partnership with John Thompson focuses on technology, sustainability, and innovation in the mining industry.  Anne was named to the WIMUK Global 100 Inspirational Women in Mining 2020.

This lecture is scheduled in a hybrid format. If you would like to join the meeting please:

Join from PC, Mac, Linux, iOS or Android: https://mines.zoom.us/j/97837642368?pwd=VWQrMmZwR0JZVW1Wayt5NExDalRhZz09
Password: 208298

The Van Tuyl lectures are scheduled at 4-5pm in BE 241/ Zoom (hybrid format), and after the lecture there will be a get-together from 5-6pm in BE 243 with pizza and sodas.