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The Relations Between Folds and Late-Formed Joints in South Pembrokeshire

Published online by Cambridge University Press:  01 May 2009

P. L. Hancock
P. L. Hancock
Affiliation:
Sedgwick Museum, Cambridge.
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Abstract

The late-formed joint sets in the Armorican belt of south Pembrokeshire are younger than both the folds and wrench faults of the region. On fold limbs these joint sets are oriented normal to bedding surface and symmetrically about axial-traces. Lens-belts and joint-drags parallel to the joint sets indicate a shearing pattern parallel to stratification planes. The orientations of fractures in collapsed blocks of Carboniferous Limestone, in Triassic breccias, show that the late joints were formed before the end of the Triassic. The term kathetal-joints is used for those which always remain normal to bedding surfaces.

Type
Articles
Information
Geological Magazine , Volume 101 , Issue 2 , 17 April 1964 , pp. 174 - 184
Copyright
Copyright © Cambridge University Press 1964

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References

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