Ion-probe zircon dating of a mid-Early Cambrian tuff in South Australia

Abstract
Ion microprobe U-Pb dating of zircons extracted from a narrow tuff band in the Lower Cambrian Heatherdale Shale of South Australia produced an age of 526 ± 4 Ma (95% confidence limits). Local and regional trilobite and archaeocyathan evidence indicates that the tuff ìs latest Atdabanian or Botomian. The tuff shortly predates the onset of the Delamerian Orogeny.