Pilkington, Mark (2007): Fractal character of oceanic crustal magnetism determined from drill hole measurements

Leg/Site/Hole:
DSDP 69 504
DSDP 70 504
DSDP 83 504
DSDP 92 504
ODP 111 504
ODP 137 504
ODP 140 504
ODP 148 504
ODP 118 735
ODP 176 735
ODP 129 801
ODP 185 801
Identifier:
2008-073289
georefid

Creator:
Pilkington, Mark
Geological Survey of Canada, Ottawa, ON, Canada
author

Identification:
Fractal character of oceanic crustal magnetism determined from drill hole measurements
2007
In: Dimri, V. P. (editor), Fractals in marine sciences
Council of Scientific & Industrial Research, New Delhi, India
36
2
97-104
A wide range of geophysical processes and rock properties has been described in fractal or scaling terms. For continental crust, well log susceptibilities, surface susceptibilities and aeromagnetic fields all tend to support a model for a 3-D magnetization distribution having a radially-averaged power spectrum proportional to some power of the spatial frequency. This simple model of the scale-invariant behaviour of crustal magnetization and the magnetic fields it produces can be exploited by several applications which require information on such spatial variation. A more realistic power spectrum, and equivalently, covariance model for continental crustal magnetization offers many advantages over the geologically incorrect assumption of a white power spectrum (equivalent to an uncorrelated distribution). Well log susceptibilities and natural remanent magnetization intensities measured for oceanic crust are shown here to exhibit scaling behaviour. Measurements from Ocean Drilling Program holes 504B, 735B, 801C and holes CY1, CY4 in the Troodos ophiolite sequence in Cyprus show overall values for the scaling exponent, between -1.36 and -0.68 for susceptibilities and between -1.52 and -0.54 for natural remanent magnetization intensities. Based on this small number of samples, scaling exponents determined for basalt, sheeted dyke and gabbro sequences within these logs show wide variation, indicating no apparent correlation between rock type and scaling behaviour.
English
Serial
Coverage:Geographic coordinates:
North:18.3835
West:-83.4357East: 156.2136
South:-32.4327

Solid-earth geophysics; Asia; boreholes; cores; crust; Cyprus; DSDP Site 504; fractals; Indian Ocean; magnetic properties; magnetic susceptibility; magnetization; Middle East; models; natural remanent magnetization; Ocean Drilling Program; oceanic crust; ODP Site 735; ODP Site 801; Pacific Ocean; paleomagnetism; remanent magnetization; spatial variations; spectra; well logs;

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