Premium
Notes on the structure and relations of the pre‐cambrian and ordovician rocks of southwestern lleyn (Caernarvonshire)
Author(s) -
Shackleton R. M.
Publication year - 1954
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.3350010408
Subject(s) - ordovician , gneiss , geology , intrusion , geochemistry , schist , group (periodic table) , volcanic rock , rhyolite , precambrian , metamorphic rock , petrology , volcano , chemistry , organic chemistry
The oldest visible Pre‐Cambrian rocks in Lleyn are pillow lavas and sediments of the Gwna Group. They are succeeded by rhyolitic tuffs (Gwyddel Beds). Schists and gneisses have been formed from these rocks. The Sarn adamellite intrusion is related to the gneisses. The Pre‐Cambrian rocks are unconformably overlain by Ordovician.