318 Upper Triassic Radiolaria and radiolarian zonation from western North America

Upper Triassic Radiolaria and radiolarian zonation from western North America - BAP #318 Radiolaria have proven to be of great value in interpreting the stratigraphy within complex geologic terranes. This report focuses on Norian age Radiolaria from strata in eastern Oregon (Rail Cabin Mudstone), Baja California (San Hipolito Formation), and the Queen Charlotte Islands, British Columbia (“Middle member” of the Kunga Formation). Fifty-four species and ten new genera are described herein. A preliminary system of radiolarian zonation (two zones, five subzones) is proposed for the Norian Stage of the Upper Triassic of western North America. This zonal system has been based upon biostratigraphic data offered by pectenacid bivalves (Halobia Bronn, 1830), as well as various ammonites. The lower Capnodoce Zone was originally defined by Pessagno (1979) and termed an Oppel Zone. In this report the Capnodoce Cone is expanded and divided into three subzones: a lower Justium novum Subzone; a mid