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On the deformation sequence in the New Harbour Group of Holy Island, Anglesey, North Wales
Author(s) -
HUDSON NEIL F. C.,
STOWELL JULIA F. W.
Publication year - 1997
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/(sici)1099-1034(199706)32:2<119::aid-gj733>3.0.co;2-j
Subject(s) - crenulation , geology , fold (higher order function) , cleavage (geology) , bedding , group (periodic table) , metamorphic rock , paleontology , seismology , tectonics , engineering , mechanical engineering , chemistry , organic chemistry , fracture (geology) , biology , shear zone , horticulture
Four phases of deformation are recorded by minor structures in the New Harbour Group (NHG) of southern Holy Island. The regional schistosity in these rocks is a differentiated crenulation cleavage of D 2 age. An earlier preferred orientation (S 1 ) is commonly preserved as crenulations within the Q‐domain microlithons of the S 2 schistosity and is demonstrably non‐parallel to bedding. F 3 folds are widely developed in S 2 and, to a lesser extent, in bedding. S 3 crenulation cleavage is sporadically developed but can be intense locally. A major antiformal fold exists in the NHG near Rhoscolyn. This fold is of D 3 age since it clearly deforms S 2 schistosity and is consistent with the vergence of F 3 minor structures. All planar structures are deformed by folds of D 4 age. © 1997 John Wiley & Sons, Ltd.