9th SAGA Biennial Technical Meeting and Exhibition

Intrepid Geophysics has adapted its existing software to include a new series of objects that can be used when
processing gradient datasets. These have the purpose of hiding the details (abstraction) of exactly what components of a
field have been observed in a survey dataset. This avoids the problem of doing a general rewrite of processing software
from the ground up for each special case. Historically, codes have mostly been written to filter, level and grid “scalar”
line data (e.g. Total Magnetic Intensity), so Intrepid Geophysics latest software update is a dramatic shift to the world of
vectors & tensors.

The Mesoproterozoic Athabasca Basin provides approximately one-third of world uranium primary production from
deposits located at or near the sub-basin unconformity, and because they are buried, geophysics plays a key role in their
exploration. This role is examined using results of recent studies near the McArthur River deposit lying at a depth of
about 550 m.

Ideas on plate tectonics started with the recognition of the remarkably similar shape of the coastlines of Africa and
South America. The elegance of the theory at global scale has to be matched eventually with evidence (both
geological and geophysical) at local scale.

The purpose of this paper is to highlight the benefits associated with the use of long offset data and some of the
practical issues encountered during acquisition and processing. The use of long offsets in shallow water settings such as
the UK Central North Sea, have yielded valuable information in the context of identifying additional potential from
existing and new plays in this mature basin.

The Mauritanides in the western part of Mauritania form a north-south striking assembly of metamorphosed rocks
from meta-sedimentary to ultra-basic and ophiolitic origin with interspaced calc-alkaline granite. Morphologically
they form a belt of low lying hills. Geologically they stand out because they contain a large number of small
copper-rich base metal deposits and a few Cr showings.

The Bushveld Complex (BC) has been the subject of many palaeomagnetic investigations since 1959. Despite these
studies, systematic inconstancies have been found between the palaeomagnetic findings and well constrained ages
determined for the Bushveld Complex.

Regional greenschist facies metamorphism (350±50°C, ca 2.5 kbar) of sediments in the Witwatersrand Basin
implies that crustal temperatures were significantly elevated at some time in the Late Archaean and
Palaeoproterozoic relative to present day temperatures.

A Coaltech-2020 Geological and Geophysical Steering Committee task was initiated in 2003 to source existing
airborne magnetic datasets over the Witbank coalfield and to collate these into a single map. The main project
benefit is to provide Coaltech-2020 participants with a more global perspective by being able to trace magnetically
susceptible dykes cross-cutting the coalfield, from beyond their individual mining leases, thereby potentially
identifying previously unknown dykes in their own areas. Potential savings to mining operations generated by
access to such additional information may be worth millions of rands.

The techniques used in space geodesy are Very Long Baseline Interferometry (VLBI), Global Positioning System
(GPS), Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR). VLBI uses the precise timing of radio
signals from distant quasars arriving at different points on earth. SLR and LLR are based on the round-trip time
required by light from ground-based laser stations to bounce off satellites or the moon (in the case of LLR) and
return to the station. GPS methods measure the travel time of radio signals between satellites and receivers on the
ground.

This paper presents a novel approach to identifying/tracking interlocking Palaeocene sand and shale filled
channels based on forward modelling, AVO classification and inversion of inversion techniques for an appraised
subtle Paleocene deep marine turbidite, Central North Sea.