Speaker: Greg Hodges – Fugro Airborne Surveys
Title: HELITEMTM Data Over Lalor and Chisel Lake Deposits
Date: Tuesday May 7, 2013
Location: 4th Floor Conference Room, Room 451, 409 Granville (UK Building at Granville and Hastings)
Video-Link: Those who are interested but unable to attend in person will be able to catch the presentation live via online GoToMeeting. Details will be provided the day before.
The test survey that detected the Lalor Lake and Chisel North deposits showed that HELITEM could detect these targets at greater than 550m depth, but it also showed some limitations of modeling and some widely accepted ideas about time domain EM. The initial modeling suggested that the deposit might not be detectable, but the survey went ahead and proved successful, exceeding the predictions. The targets were flown and re-flown with several pulse widths and base frequencies, and the results generally matched prediction from theory, but not always intuitive assumptions. The deposits are well known from extensive drilling and the results of the survey have since been modeled with both discrete plate conductors (LeroiAir) and 3D UBC inversions with good results, but once again some mysteries become apparent.
Post-Talk: Those interested are encouraged to head to Moose’s Downunder after the talk
A short course on the why, how, and what of geophysical inversion
Presented by the B.C. Geophysical Society
Date: April 24th – 26th 2013
Address: SFU Downtown Campus; Vancouver BC
Registration: Registration is now open! Please fill out attached pdf form (link below) and click submit. Registration will be complete once payment is made via Paypal link. Delegates are asked to choose one workshop day among April 25th or 26th.
Day 1 – Presentations
Introduction to inversion in exploration
- Reasons for doing inversion
- Range of inversion options: magnetics, gravity, EM, IP-resistivity, seismic
- Fitting geology and data
Background on inversion
- Joint and collaborative
- The future of inversion
Before inversion – forward modeling
- forward modeling
- petrophysics drives the story
- complexity vs. adequacy
- Potential fields
Day 2 – Workshop with Case Studies
Multi-disciplinary teams will use geological, geophysical and geochemical data from two deposits (Babine Lake porphyry Cu-Mo, BC and Minto Cu, YK) to develop exploration targets. Teams will present their evaluations of the data to stimulate group discussion.
Inversion results for the available geophysical surveys will be presented to demonstrate state-of-the-art technology (http://geosoft.com/, http://www.mirageoscience.com/) and best practices.
|Sponsors for the short course are currently being solicited. Please contact Victoria Sterritt at Victoria.Sterritt@teck.com for details. Proceeds go to the KEGS Foundation.
|For those interested in more information about the short course, please email firstname.lastname@example.org
The BCGS would like to thank RedTail Metals and Capstone Mining Corp. for providing access to the Babine Lake and Minto data sets.
SPEAKER: John A. Chapman, P.Eng
TITLE: The importance of mineral exploration and mining to humans in their space development activities
DATE: Thursday February 21st, 2013
LOCATION: Room 451, 409 Granville Street (UK Building at Granville and Hastings)
ABSTRACT: There is presently a surge of government and commercial space initiatives that harkens the beginnings of a new age – that of space development beyond Earth orbit. Dot-com billionaires along with well educated and experienced space scientists, engineers and technologists have begun forming companies focused upon advancing human civilization toward utilization and occupation of the moon, mars and asteroids.
The wealth from mines, from the dawn of recorded human history, is the epic march of mankind along the path of progress. It was the mines that made ancient civilizations such as Egypt, Greece and Rome great and in more recent times have created immense wealth to the benefit of the people of Europe, North America, Australia and now China, India, Brazil and Russia.
Today, we are part of the “space generation”, crawling off the surface of the earth into the “oceans of space” – mining will continue to provide the capability for humankind to advance to the moon, mars and on to the stars.
Where: Chairman Room – Westin Bayshore Hotel, 1601 Bayshore Drive Vancouver
When: 7:30 am – Tuesday, January 29th, 2013.
Registration: Sold out
Speaker: James Siddorn
Practice Leader (Structural Geology) for SRK Consulting, Toronto
Topic/Abstract: “Advanced Geological Interpretation of Aeromagnetic Data: Applied Indirect Exploration Targeting”
Aeromagnetic surveys are a widely recognized exploration technique in mineral exploration especially in covered terranes. They are often not used to their full potential, with direct anomaly targeting and lineament analyses conducted but little else. The real value in aeromagnetic data can be unlocked integrating multiple datasets into the interpretation of the data with the aim to produce a coherent geological map which outlines the structural and geological history.
Geological models are a primary component of the interpretation process; in order to present an interpretation of the geology of the region there needs to be a coherent framework of stratigraphic and structural principles that form the basis of the interpretation. Individual rock unit and structural elements identified on the aeromagnetic images can then be related to components of the geological models. Individual structures can be interpreted in both a time and space context, with an outline of when and how faults moved. In turn, the spatial distribution of mineral deposits in relation to structures becomes evident and can be related to the geological evolution of the region, not just the geometry.
Advanced aeromagnetic interpretations should produce structural/geological maps showing the relative timing of structural events with a focus on commodity specific exploration targeting. This talk will outline an interpretation method with examples of final products for a series of geological terranes.
SPEAKER: Justin Granek (MSc)
TITLE: Computing Geologically Consistent Models from Geophysical Data
DATE: Wednesday, November 28th 2012
LOCATION: Room 451, 409 Granville (UK Building at Granville and Hastings)
ABSTRACT: The difficulty of finding economically viable mineral deposits has motivated the development of new exploration methodologies. This has led to greater efforts from the geophysical community to incorporate available sources of geological and geophysical information. Since the suite of available data types is diverse, the synthesis of multiple sources of information into a single coherent model can present many difficulties. In particular, the incorporation of geological constraints in the inversion of geophysical data has been investigated by various researchers.
While valuable information can be gleaned from geological data, a challenge remains due to the disconnect between geological units and geophysical property values. Though descriptive, a distinct geological unit is not always able to uniquely characterize the physical properties of a volume of earth, and vice versa. Interpretation and translation to and from geological and geophysical units can introduce bias based on the expert’s experience.
Current methodologies which exist to incorporate geological and geophysical information into inversion typically suffer from at least one of the following issues: either they require the user to interpret physical property values from geological information, or else they require the user to define some range of influence for each measurement in the model. Imposing constraints on a model which are biased in one of these ways can lead to recovered models unsupported by the data.
The introduced methodology differs from previous attempts at incorporation of a priori information since it applies statistical classification of in situ physical property measurements (as opposed to physical property values inferred from geology) as the basis for constraints. Statistical classification, combined with the iterative nature of the scheme, act to propagate the information from the downhole physical property logs through-out the model with minimum user input required. This automated approach reduces the potential for bias from unsupported constraints, while maximizing the integration of the classification results.