- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
The stages in the formation of a complex small bent-fold structure in the angle of the Donegal granite outcrop are outlined and analyzed. The structure probably originated as an upright curved cross fold with a west-northwest-east-southeast trend. Later it was bent to a north-south trend, with production of small drag folds, possibly by forces related to the intrusion of the Older Granodiorite. This was accompanied by development of downdip lineations. Gentle folding of the flat block and mullion development were caused by subsequent intrusion of the Main Granite. Z-folds were formed in the hinge of the bend. Bending must have taken place under plastic conditions.