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The stress state near Spanish Peaks, colorado determined from a dike pattern

Pure and Applied Geophysics PAGEOPH

By:
,
DOI: 10.1007/BF01637098

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Abstract

The radial pattern of syenite and syenodiorite dikes of the Spanish Peaks region is analysed using theories of elasticity and dike emplacement. The three basic components of Ode??'s model for the dike pattern (a pressurized, circular hole; a rigid, planar boundary; and uniform regional stresses) are adopted, but modified to free the regional stresses from the constraint of being orthogonal to the rigid boundary. Dike areal density, the White Peaks intrusion, the strike of the upturned Mesozoic strata, and the contact between these strata and the intensely folded and faulted Paleozoic rocks are used to brient the rigid boundary along a north-south line. The line of dike terminations locates the rigid boundary about 8 km west of West Peak. The location of a circular plug, Goemmer Butte, is chosen as a point of isotropic stress. A map correlating the location of isotropic stress points with regional stress parameters is derived from the theory and used to determine a regional stress orientation (N82E) and a normalized stress magnitude. The stress trajectory map constructed using these parameters mimics the dike pattern exceptionally well. The model indicates that the regional principal stress difference was less than 0.05 times the driving pressure in the West Peak intrusion. The regional stress difference probably did not exced 5 MN/m2. ?? 1977 Birkha??user Verlag.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
The stress state near Spanish Peaks, colorado determined from a dike pattern
Series title:
Pure and Applied Geophysics PAGEOPH
DOI:
10.1007/BF01637098
Volume
115
Issue:
1-2
Year Published:
1977
Language:
English
Publisher:
Birkha??user-Verlag
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Pure and Applied Geophysics PAGEOPH
First page:
69
Last page:
86