ONLINE WORKSHOPS

 

Teaching and networking events held before the conference.
Sunday, 29th August 2021

Location:

CONFERENCE ONLINE PLATFORM

from:

Collegium Basilea, Institute for Advanced Study,

Basel, Switzerland (Workshop 1)

University of Warsaw, Faculty of Geology, Warsaw, Poland (Workshop 2)

 

1. Workshop on low temperature geochemical modelling using PHREEQC

LEADERS: Prof. Mark Tyrer (Collegium Basilea), Prof. Andy Watson (Collegium Basilea), Dr Andy West (Collegium Basilea)

DATE: Sunday, 29th August 2021
PARTICIPANTS: min. 25 – max. 50
DURATION: 9.00 a.m – 4.00 p.m
break for lunch: 12.00 – 13.00
PRICE: 120 EUR

DESCRIPTON:
This introductory workshop introduces new users to modelling the interaction of minerals with their pore solutions, by simulating thermodynamic equilibrium using the code PHREEQC.
The workshop assumes no previous experience of thermodynamic modelling and aims to equip new users with the ability to make good use of the many training resources available on the web. Although PHREEQC is an excellent code and has very good documentation, many users feel their initial progress could be helped with some guidance. This course is intended to take new users through a number of exercises which will build confidence and understanding. A number of training resources will be highlighted which should enable course participants to undertake more advanced simulations with confidence after the course.
The initial presentation outlines the theoretical basis of the modelling methods using worked examples of reactions between solid phases and a solution at thermodynamic equilibrium. The major part of the training course is concerned specifically with mineral and solution chemistry and examines how the user can simulate the following phenomena and types of reaction:

Speciation of a solution and the predicted properties of a solution
Temperature dependence
Precipitation-dissolution reactions
Acid-base reactions
Redox processes
Gas-liquid reactions

At this stage, examples of complex, multi-component problems will be examined and a few ‘tricks of the trade’ will be demonstrated such as simulating the amount of a reaction required to reach a phase boundary, how to read external solution descriptions from a spreadsheet and how to fix (and vary) the pH of simulations to examine how speciation is affected by changes in acidity.
Later in the workshop, we will examine how the geochemistry of ideal and non-ideal solid solutions can be simulated. This is important in natural systems as many minerals do not exist as pure stoichiometric solids in nature.
The session concludes by reviewing some of the many resources available to PHREEQC users on the web. This includes data sources, coupled chemical transport calculations using PHREEQC, the use of PHREEQC in chemical simulators for predominance area calculations and introduces a web-based version of the code.

ADDITIONAL INFO:
A list of resources to download and install will be circulated in advance of the workshop.

 

2. Tackling the issues of quantitative x-ray spectrometry: the Precise, the Inaccurate and the Artificial

LEADERS: Prof. Bogusław Bagiński (University of Warsaw), Dr. Petras Jokubauskas (University of Warsaw)

DATE: Sunday, 29th August 2021
PARTICIPANTS: min. 12 – max. 14
DURATION: 9.00 a.m – 4.00 p.m
break for lunch: 12.00 – 13.00
PRICE: 50 EUR

DESCRIPTON:
This is a workshop at advanced level. All attending X-ray cowboys are expected to have at least basic knowledge or experience of SEM/ EPMA and x-ray microanalysis techniques.

The workshop tackles the advanced issues of quantitative x-ray microanalysis techniques of SEM and EPMA (WDS and EDS) applied for challenging analytical situations. The preliminary plan is to have a set of oral presentations followed by practical demonstrations on real instruments with real minerals. The emphasis will be on REE-bearing minerals (xenotime, fergusonite, chevkinite), but most techniques are applicable to other complicate mineral phases built from elements of subsequent atomic numbers (Mn-Zn, Ru-Cd, Sr-Nb, Hf-Hg, … peculiarities common in the ore geology domain).

The main topics:
• What is a good element standard, how precision determination works (or does not work) on EPMA? (→How to get good precision?)
• Advanced overlap correction techniques (→ overcoming the bad inaccuracies and artifacts)
• Realistic countermeasures for secondary Fluorescence (→ dealing with the ugly artifact which is often overlooked)