Orogenic events 1:500 000 (DMIRS-036)

The digital map ‘1:500 000 orogenic events of onshore Western Australia, 2018’ is based on the ‘1:500 000 State interpreted bedrock geology of Western Australia, 2016’ and ‘1:500 000 tectonic units of Western Australia, 2017’, together with GSWA and GA (AGSO, BMR) regional geological maps at scales from 1:250 000 to 1:1 000 000. The dataset is presented as a single layer of overlapping event polygons arranged with the oldest events at the bottom and the youngest at the top. Recognized events include structural deformation, magmatism, metamorphism, and resetting of isotopic systems, although the events depicted in this dataset are primarily orogenic. The nomenclature and hierarchy for the orogenic events are based on the GSWA Explanatory Notes System, November 2017. Event boundaries are based on available evidence, which includes structural, geochronological, and isotopic data, and are restricted to the exposed limits of the affected tectonic units and constituent lithostratigraphic units as defined in the GSWA Explanatory Notes System. Some areas, such as the Yilgarn Craton granites, some Yilgarn Craton greenstones, and the Narryer Terrane presently lack sufficient data to assign event divisions.