Australia: The Land Where Time Began

A biography of the Australian continent 

The Glikson Impact Structure was discovered as a aeromagnetic and structural anomaly in the Little Sandy Desert of Western Australia, in an area of otehrwise flat cpuntry of sandstone, siltstone and conglomerate of the Mundadjini Formation, of Neoproterozoic age, as well as dolerite sills protruding into these strata. It is in the northwestern Officer Basin. A highly deformed central region contained shatter cones and planar microstructures in quartz grains. An area of deformation 19 km in diameter is defined by circumferential shortening folds and bedding that is exposed in a chaotic manner.

It was first detected as a strong aeromagnetic anomaly of ring-shape with an inner diameter of 10 km and 14 km in outer diameter. The circular magnetic signature has been interpreted as the truncation folding of mafic sills into a ring syncline. It is believed the sills probably correlate with dolerites intruding into the Boondawari Formation about 25 km to the north. An age has been obtained for the dolerite of this formation 508 +/- 5 Ma (SHRIMP U-Pb baddeleyite and zircon). This has provided a precise older limit to the impact event represented by the Glikson structure (Macdonald, Wingate & Mitchell, accepted 12/2004). Published in Australian Journal of Earth Sciences.

Sources & Further reading

1. Geology and age of the Glikson Impact structure, Western Australia