Tectonic evolution of the far western and northern Gawler Craton

Abstract

The Gawler Craton is an extensive region of Archaean to Mesoproterozoic crystalline basement underlying approximately 440 000 km2 of central South Australia that has seen extensive tectonothermal events. The tectonics of the region are particularly important in both mineral exploration and Palaeoproterozoic reconstruction models. A potential key to the understanding of both is the Nawa Domain which ties the Late Archaean-Early Palaeoproterozoic core of the Gawler Craton to the Mesoproterozoic Musgrave Province. The Nawa Domain covers an area of approximately 150,000 km2 on the northern edge of the Gawler Craton. Despite extensive geological exploration throughout, little is known of the significant geological history and formation of the region. An understanding of the evolution and tectonic history of the Nawa Domain as a part of the Gawler Craton could provide significant insight into establishing future economic prospects and would have particular importance in Palaeoproterozoic reconstruction models. The significant tectonic history and geology of the Gawler Craton has been examined and described over the following durations, the Archaean, Paleoproterozoic, and the Mesoproterozoic. It should be noted that in this duration the Gawler Craton records the effects of at least 7 regional-scale tectonothermal events. Recent studies have indicated that of these tectonothermal events, the Kimban has particular significance in the western and northern Gawler Craton which is reflected in the results of this study with zircon and monazite ages as reflecting Kimban aged deformation. This study focuses on application of U-Pb LA-ICP-MS zircon and monazite geochronology to constrain the timing of deformation of metamorphism in the northern Gawler Craton with microprobe analysis defining peak metamorphic conditions.