Gascoyne Complex

The Gascoyne Complex is a terrane of Proterozoic granite and metamorphic rock in the central-western part of Western Australia.

The Gascoyne Complex is thought to record the collision of these two different Archean continental fragments during the Capricorn Orogeny at 1830–1780 Ma.

The Gascoyne Complex is separated from the Yilgarn Craton to the south by a major fault, the Errabiddy Shear Zone.

To the north, schist of the Gascoyne Complex probably pass with decreasing intensity of metamorphism into metamorphosed sedimentary rocks of the upper Wyloo Group.

Both of these orogenies were marked by extensive folding, faulting and metamorphism, and were accompanied by the intrusion of large volumes of granite referred to as supersuites.

The Moogie metamorphics consist of schist and gneiss, which represent deformed and metamorphosed sandstone, siltstone and shale, and carbonate rocks.

The oldest, and possibly most abundant, rock type is a mesocratic, foliated to gneissic diorite to tonalite, which is typically pegmatite banded.

The maximum depositional age of the Pooranoo Metamorphics is constrained by detrital zircon dates of 1680 +/- 14 Ma derived from arenaceous metasediments.

These are divided by the Ti Tree Creek Lineament, a multiply reactivated fault which bisects the Gascoyne Complex.

The Moorarie supersuite consists of voluminous granites intruded across the Gascoyne Complex at c. 1830–1780 Ma and are syntectonic with the Capricorn Orogeny.