查看文章

The Avalonian and Cadomian terranes of the northern Appalachians and western Europe together record a ∼ 700-540 Ma orogenic event characterized by; (1) widespread, late Precambrian arc volcanism and calc-alkaline plutonism; (2) broadly coeval volcanogenic turbidite deposition often accompanied by mafic volcanism; (3) predominantly sinistral motions on major shear zones locally associated with latest Precambrian terrestrial sedimentation and bimodal volcanism; and (4) deposition of shallow-marine Cambro-Ordovician overstep sequences containing Acado-Baltic faunas.

The record is interpreted to trace a tectonostratigraphic evolution from late Precambrian extensional magmatic arc, through latest Precambrian transform margin, to early Paleozoic shallow-marine platform. Arc-related activity is attributed to oblique subduction and the development of predominantly ensialic volcanic arc basins. The …