terrane
1. A fault-bounded area or region which is characterized by a stratigraphy, structural style, and geologic history distinct from those of adjacent areas, and which is not related to those areas by un-conformable contacts or facies changes. This usage has recently become frequent in studies of orogenic belts in which terranes can have origins as accretionary wedges, island arcs, and microplates. Initially, ‘displaced’ or ‘allochthonous’ was used to qualify the word ‘terrane’ and to distinguish such terranes from merely ‘suspect terranes’, but all three qualifiers are falling into disuse.

2. N. American spelling of terrain, increasingly coming into general usage.

terrane See terrain.