The digital '1:500 000 tectonic units of Western Australia, 2017' has been compiled using boundaries derived from the digital '1:500 000 State interpreted bedrock geology of Western Australia, 2016' following the principles first used on the '1:500 000 Tectonic units of Western Australia — Preliminary Version' (2007). For the offshore component, the map uses data and divisions from the Geoscience Australia ‘Australian Geological Provinces’ GIS dataset, with polygons adjusted to match seamlessly into the onshore tectonic elements. The nomenclature and hierarchy for the tectonic units are based on the GSWA Explanatory Notes System. The State is the highest level unit in the hierarchy, and is subdivided at the next level into Archean to Paleoproterozoic cratons; Proterozoic orogens; Archean, Proterozoic and Phanerozoic basins (or superbasins); and igneous supersuites. All units depicted on this map, with the exception of basins and some igneous supersuites, are at the third or lesser hierarchical level. Cratons are subdivided into superterranes, terranes, and domains. Orogens are divided into provinces and orogenic forelands, and may also incorporate sedimentary basins; provinces are further subdivided into terranes/zones. The reworking of basins and craton margins into orogens and orogenic forelands is represented on a companion layer, the '1:500 000 orogenic events of onshore Western Australia, 2015'. Igneous supersuites are further divided into suites, and both may be constituents of cratons, orogens, or large igneous provinces (LIPs). Basins are divided into sub-basins and sub-basin elements, which include shelves, highs, terraces, arches, platforms, ridges, troughs, embayments and grabens, and are locally ranked and stacked according to age where units overlie each other. The order of overlapping polygon units is indicated by the DRAWORDER field; the draw order may display incorrectly in the MapInfo format type. Any tectonic unit within the hierarchy may also be preserved as an inlier or outlier, in which case it is depicted as a separate unit. Polygons on this map represent the present-day area of tectonic units, without inference on their original extent.
