Zobrazeno 1 - 10
of 16
pro vyhledávání: '"Dean Hillan"'
Publikováno v:
Ore Geology Reviews. 109:290-302
Remanent magnetization dominates induced magnetization in several types of mafic-ultramafic magmatic rocks, and where it is strong, allows remote targeting of mafic lithologies based purely on their magnetization direction. We evaluate practical meth
Publikováno v:
Journal of Applied Geophysics. 109:242-255
Magnetic modelling can be a powerful tool for understanding the architecture of numerous types of mineralized systems; e.g., iron ore, IOCG and porphyry deposits. In such modelling, the induced component is generally assumed to be dominant, whereas r
Publikováno v:
Preview. 2014:41-44
Rocks from the Musgrave Block (Figure 1) are mainly composed of granulite facies quartzofeldspathic metasedimentary and meta-igneous rocks, but also include a suite of layered mafic to ultramafic intrusions, known as the Giles Complex. The Giles Comp
Equivalent Sources: Rapid Calculation in the Frequency Domain and Application to Leveling Correction
Autor:
Phillip W. Schmidt, Dean Hillan
Publikováno v:
ASEG Extended Abstracts. 2013:1-4
The equivalent source is usually calculated by an iterative method, designed to converge on the observed potential field, magnetic or gravitational. Each iteration involves two Fourier transforms, one forward and one inverse. As the number of grid po
Publikováno v:
ASEG Extended Abstracts. 2013:1-4
A magnetic body has a resultant magnetisation that is the vector sum of its induced and remanent components. Ignoring the role of remanence may lead to erroneous resultant magnetisation direction and hence inaccurate geophysical models. Determination
Autor:
Dean Hillan, Clive Foss
Publikováno v:
ASEG Extended Abstracts. 2012:1-4
Aeromagnetic surveys collected over bodies of high susceptibility record fields that have been significantly affected by self-demagnetisation. These effects complicate interpretation as the amplitude of the magnetic response scales non-linearly with
Publikováno v:
ASEG Extended Abstracts. 2012:1-4
The direction of magnetization of a compact source causing a magnetic field anomaly can be found without concern for the details of its shape using magnetic moment analysis (MMA). This provides assistance in the successful inversion of magnetic anoma
Publikováno v:
ASEG Extended Abstracts. 2012:1-4
Magnetic field interpretation is often conducted on an incorrect assumption that remanent magnetization is insignificant and that the resultant magnetization direction is in the local geomagnetic field direction. For compact anomalies various methods
Publikováno v:
Proceedings.
An elongated cylinder, modelled as a polyhedron with polygonal ends and elongated rectangular side facets, leads to a growing numerical instability in the computed magnetic gradient anomaly as the curved surface is discretized more faithfully with in
Autor:
Dean Hillan
Publikováno v:
London 2013, 75th eage conference en exhibition incorporating SPE Europec.
The assumption of a linearly induced magnetisation begins to break down in bodies with moderate to high susceptibilities. These bodies exhibit self-demagnetisation effects which tend to suppress the observed field and rotate the magnetisation vector