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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

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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

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Open magnetics at pole 1VD with Noddy

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In this case the fault positions are still quite clear in the magnetic data
Faults at 20° to dyke

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Open magnetics at pole 1VD with Noddy

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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°

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Open gravity with Noddy

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Open magnetics with Noddy

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Open magnetics at pole with Noddy

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Open magnetics at pole 1VD with Noddy

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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 = 1k = 10-2
background
r = 0k = 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

All models created using
Noddy
Copyright © 1998-2002 AGCRC & Mark Jessell

WWW conversion by Ian Brayshaw