Paleomagnetic results from the Cambrian-Ordovician boundary section at Black Mountain, Georgina Basin, western Queensland, Australia

Abstract

Zones of alternating magnetic polarity have been identified throughout the Cambrian-Ordovician sequence at Black Mountain, and can be presumed to record geomagnetic field reversals during or immediately after deposition. A strong correlation can be made to polarity zones recognized at Dayangcha, northeastern China, a candidate site for establishment of the Cambrian-Ordovician boundary Global Stratotype Section and Point. Polarity zones associated with the Hispidodontus discretus and Hirsutodontus simplex Assemblage-Zones at Black Mountain are absent at Dayangcha, suggesting hiatuses at these levels in the Dayangcha sequence. Secondary components preserved in the Black Mountain section may provide temporal constraints on Middle Paleozoic diagenetic events in the Burke River Structural Belt