Potential fields: a (re)introduction for geophysicists and geologists

Australian Institute of Geoscientists > Events > ASEG, data interpretation, exploration, geophysics, magnetics, mapping, potential fields > Potential fields: a (re)introduction for geophysicists and geologists

Potential fields: a (re)introduction for geophysicists and geologists


 

Australian Society of 8 CPD hoursExploration Geophysicists Oz-Step Course presented by by Bob Musgrave, Tuesday October 13th, 2015

Who should attend?

Geophysicists, who wish to update/expand their appreciation of the use of potential field techniques; geologists, who use gravity and/or magnetic data in mapping, exploration or interpretation (or who should do so!).

Course Description

Prerequisites: basic geology. No prior geophysical training is necessary, and the maths will be kept “light”, so the course should be accessible to all geoscientists – but there will be the opportunity for more sophisticated discussion for those with established skills in geophysics.

Session 1 – Basics

  • Course overview and scope
  • Basic form of potential field anomalies
  • Data acquisition
  • Scalar, gradient and tensor data. Earth’s gravity and magnetic fields

Session 2 – Physical properties

  • Density and magnetic susceptibility
  • Remanence
  • Magnetic properties and mineralisation
  • Microbes and magnetic diagenesis

Session 3 – Data presentation and filtering

  • Derivative filters; phase filters and the tilt filter.
  • Edge analysis (“worming”).
  • Euler depths; spectral depths. Curie depth.
  • Isostatic correction.
  • Tensor and gradient data interpretation.

Session 4 – Potential field inversion

  • Source mapping; derivative maps; inferring lithology.
  • Direct inversion, and its limitations.
  • Geologically constrained inversion.
  • Remanence and inversion.
  • Case studies.

Biography

Bob Musgrave is the Research Geophysicist with the Geological Survey of NSW. Bob graduated with a BSc (Hons) from the University of Sydney in 1981, majoring in geology and geophysics. Bob went on to complete a PhD (1987) at the University of Sydney in palaeomagnetism. Bob’s interests in tectonics, palaeomagnetism and magnetic petrophysics led him through post-doctoral fellowships at Victoria University of Wellington (1987), the Australian National University (1988-89), and the University of Tasmania (1989-91). Bob went on to join the Ocean Drilling Program, based at Texas A&M University (1991-93), and to date has sailed on 5 ODP/IODP expeditions, the most recent in 2014. Returning to Australia, Bob was a Senior Lecturer in geophysics at La Trobe University until 2003. Bob was then a Senior Research Fellow at Macquarie University, before joining the Geological Survey of NSW in 2005. Bob is currently also a Conjoint Senior Lecturer at the University of Newcastle and an Honorary Associate of the University of Sydney. Bob’s initial interest in palaeomagnetism has broadened over the years into a diverse range of applications, from magnetostratigraphic dating and tectonics, to magnetic petrophysics studies of hydrocarbon migration, gas hydrate accumulation, and the relationship of mineralisation processes to remanence-dominated magnetic anomalies. His work with GSNSW has emphasized applications of magnetic and gravity studies, including novel data filtering and presentation, long-wavelength interpretation and integration with passive seismic datasets, and joint magnetic and gravity inversion of complex tectonic settings. His research has yielded more than 50 peer-reviewed publications.

Click here for further information regarding the course and registration information.  Please register by 8th October 2015.  Registrations may only be made on-line.

Registration

ASEG member:                  $275.00
ASEG Student member:     Free
Non-ASEG member:          $425.00
(Cost include course notes, lunch with morning & afternoon tea)