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3.1 Faulted dyke

These models demonstrate the effects of varying the fault orientation with respect to a vertical dyke, and the ease with which the fault orientations cand displacements can be recognised.

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Link	Block	Gravity	Magnetics	Magnetics	Magnetics at Pole	Magnetics at Pole 1VD
Faults at 90° to dyke	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE
	In this model the apparent offsets are quite clear, although the results of section 2.2.5 show that the true offsets cannot actually be determined from this data.
Faults at 45° to dyke	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE
	In this case the fault positions are still quite clear in the magnetic data
Faults at 20° to dyke	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE
	In these images the fault positions and orientations start to become unclear, and the variations in dyke appearance along strike could be interpreted as thickness variations or rock property variations.
Faults at 60° to dyke, dipping at 60°	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE	LOAD JPEG IMAGE
	This model re-emphasises the problem with reinterpreting true fault offsets from faults cutting a single marker horizon. (See section 2.2.5 for further examples.)

Key	Survey Parameters	Scales
dyke r = 1 k = 10-2 background r = 0 k = 0 image width 10,000 m	Inclination -50° or -90° Intensity 50,000 or 70,000 gamma Flight height 80 m	max min max min

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Copyright © 1998-2002 AGCRC & Mark Jessell

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