Early Triassic (Smithian) ammonites of paleoequatorial affinity from the Chulitna terrane, south-central Alaska

Abstract

Lower Triassic limestone is part of the unique stratigraphic suc cession of the Chulitna terrane. This terrane is believed to be a greatly displaced lithosphere fragment whose exposures are limited to a 400 km2 area on the south flank of the central Alaska Range in Alaska. The nearest known correlative Lower Triassic marine strata are located hundreds of kilometers distant in northern Alaska and northwestern British Columbia; in general, they are not represented elsewhere among the oceanic-volcanic pre-Tertiary sequences of the entire circumpacific margin.