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Jointing and minor tectonics of the Vale of Glamorgan between Ogmore‐By‐Sea and Lavernock Point, South Wales
Author(s) -
Roberts J. C.
Publication year - 1974
Publication title -
geological journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.721
H-Index - 54
eISSN - 1099-1034
pISSN - 0072-1050
DOI - 10.1002/gj.3350090201
Subject(s) - geology , mesozoic , tectonics , basement , fault (geology) , paleontology , joint (building) , seismology , archaeology , geography , structural basin , architectural engineering , engineering
Joints and faults were studied in Mesozoic and Avonian strata along 35 km of coast between Ogmore‐by‐Sea and Lavernock Point, Glamorgan, South Wales. Observations on joint and fault planes were recorded at 22 localities (i.e. approx. 750 stations), an analysis of which suggests the following. In the Mesozoic strata systematic joint patterns of tectonic origin exist with principal azimuths at 340°, 200° and 280°, with the more complex patterns characteristic of Triassic sequences, whilst a System of orthogonal microjoints (striking at 280°–190°) representa perhaps the earliest formed fractures in the Mesozoic strata. The joints in general formed early in the deformation of the area, whilst joints and faults can both be ascribed to a general northsouth compressive force. A study of fracture patterns in Avonian basement reveals a close similarity of trend, but there is little visible evidence to indicate much basement influence on cover tectonics.