Orogeny

Coordinate term: taphrogeny

The effects of Acadian orogeny are concentrated in central Newfoundland, decreasing in intensity to the east and west (Williams, this volume).

When I asked Geoff Milnes what age the rocks were before they were turned into uncompromising gneisses by the Alpine orogeny he made a rueful face.

In Canada the fold-thrust belt formed during what is termed the Columbian orogeny (Monger and Price, 2002). Because the Sevier and Columbian orogenies were contemporaneous and constitute a single continuous and linear belt of rocks and structures, I use the term Cordillera orogeny to refer to the Cretaceous deformation that created the entire belt, whereas the term Laramide is used only to refer to a series of Late Cretaceous—Tertiary basement-involved uplifts, for the most part located in the Rocky Mountain foreland east of the fold-thrust belt and mainly south of the Lewis and Clark lineament (Fig. 1) in keeping with the original definition by Armstrong (1968).