R.B. Flint A.J. Parker K.R. Ludwig A.H. Blissett C.M. Fanning 1988 <p><span>Through the application of both conventional U-Pb zircon analyses and small-sample U-Pb isotopic analyses, the nature and timing of tectonic events leading to the formation of the Gawler Craton have been defined more precisely. Constraints on deposition of Early Proterozoic iron formation-bearing sediments have been narrowed down to the period 1960-1847 Ma. Deformed acid volcanics, including the economically important Moonta Porphyry, have zircon ages of ∼ 1790 and 1740 Ma. The voluminous acid Gawler Range Volcanics and correlatives to the east were erupted over a short interval at 1592 ± 2 Ma, and were intruded by anorogenic granites at ∼ 1575 Ma. Small-sample zircon analyses proved to be an extremely valuable adjunct to conventional analyses, generally yielding more-concordant data which forced a curved discordia through an upper intercept slightly younger than from a conventional straight-line discordia.</span></p> application/pdf 10.1016/0301-9268(88)90076-9 en Elsevier Refined Proterozoic evolution of the Gawler Craton, South Australia, through U-Pb zircon geochronology article