The metamorphic history of the Loch Tummel area, central Perthshire, Scotland

During the Laxfordian orogenic period dolerite intrusions crosscut and were chilled against vertical bands of hornblende schist that trend N.W.-S.E. Subsequent metamorphism affected both the regional hornblende schists and the dolerites, and narrow bands of hornblende schist were formed in places at the expense of doleritic chilled margins. Previous interpretations of Lewisian geochronology, tectonics and metamorphic history made on the basis of a unique pre-Laxfordian basic dyke phase, cannot be applied to the rocks south of Gairloch.

Section: Discussionmentioning

confidence: 85%

Age Relations of Lewisian Basic Rocks, South of Gairloch, Ross-shire

Bowes

Ghaly

1964

“…These show no preferred orientation and have overgrown all the preexisting F 2 deformation displayed by the host-fabric. Rast (1958) and Sturt and Harris (1961) have described the comparable static growth of porphyroblasts during the intervals between several episodes of folding in the polyphasal Dalradian schists.…”

Section: Time and Placementioning

confidence: 97%

The Metamorphism of the Manx Slate Series, Isle of Man

Simpson

1964

Previous research by the present author has established the Caledonian tectonic history of the Manx Slate Series. In particular three episodes of folding (Fi, F 2 , F 3 ) were recognized. The present contribution describes the sequence of metamorphic textures impressed on these metasediments during this polyphase deformation.Two distinct episodes of metamorphism have affected the Manx Slate Series. A syn-tectonic F! metamorphism produced a chloritezone alteration throughout the Island. A later F 2 metamorphism was primarily responsible for the growth of small porphyroblasts of several minerals within the pre-existing F t fabric. This second metamorphism is confined to the hinge of the large-scale F 2 Manx synform and its effects are visible in an elongate belt following the middle of the Island. The emplacement of the porphyroblasts began during the F 2 movement and continued into the static interval which preceded the third (F 3 ) movement-phase. It was completed prior to the F, deformation.

“…The metamorphic terminology in respect to the deformation phases (Dl, D2, etc.) is that of Sturt & Harris (1961) which consists of MS-syntectonic, and MP-post tectonic, with a suffix number which refers to the phase of deformation. …”

Section: Terminologymentioning

confidence: 99%

Metamorphism of Caledonian Metadolerites in North-west County Mayo, Ireland

Max

1970

Caledonian dolerite dykes in northwest County Mayo, Ireland, are differentially metamorphosed with volumes of largely unmetamorphosed dolerite grading into marginal amphibole schists with no preserved igneous textures. Deformation controlled the extent of the metamorphism. The lack of a significant differential strain in the volumes of preserved igneous rock is considered to be the cause of the preservation.