Carboniferous Conodonts, Algae, and Foraminifers from Lisburne Group, Prudhoe Bay, Alaska: ABSTRACT

Abstract

Continuous cores from the ARCO/Exxon South Point State 1 and Pingut State 1 wells at Prudhoe Bay penetrated the Carboniferous Wahoo and Alapah Limestones of the Lisburne Group. The upper Alapah and the entire Wahoo were examined for conodonts, foraminifers, and algae. The Alapah and Wahoo Limestones contain abundant but low-diversity foraminifer and conodont faunas. The succession of foraminifers and conodonts is used to develop a detailed local zonation for well-to-well correlations. The larger scale aspects of the zonation permit correlation of the Alapah and Wahoo Limestones with the Carboniferous section in western Europe as well as the Mississippian and Pennsylvanian sequences of North America. The Alapah Limestone is characterized by foraminifers of zones 16s through 19. Conodonts from the uppermost Alapah (zone 19) include Gnathodus girtyi simplex and Rhachistognathus muricatus and are assigned to the muricatus zone. The boundary between the Alapah and the overlying Wahoo coincides with a nondiagnostic interval between foraminifer zones 19 and 20 and with the first appearance of rare specimens of Declinognathodus noduliferous. The first appearance of D. noduliferous is coincident with the mid-Carboniferous boundary and occurs in close proximity to the Mississippian-Pennsylvanian boundary in North America. Foraminifer zones 20 and 21 are easily recognized in the Wahoo and can be integrated with four conodont zones. The conodont zones in the Wahoo are believed to be sensitiv to environmental fluctuations and may be of only local biostratigraphic significance. End_of_Article - Last_Page 658------------