Structural and metamorphic evolution of rocks in the Mann Ranges

Project Investigators

Lachlan Hallett (Hons. 2007)

Doctor Alan Collins

Associate Professor Martin Hand

The Mann Range region in the central Musgrave Block has been out of bounds to geologists for the past 30 years, and is therefore one of the least known geological terrains in Australia. It is a region of spectacular scenery and voluminous outcrop, and is now becoming accessible via negotiations undertaken by PIRSA. Work undertaken by the Northern Territory Geological Survey in the small part of the Mann Ranges that extends into the NT has shown it contains the highest pressure regional-scale rock system in Australia. This tectonism reflects the effects of the 600-550 Ma Petermann Orogeny, which was a massive intracratonic orogenic event that exhumed rocks from depths of around 50km. The Mann Ranges preserve the deepest part of that exhumed crust.

In this project, field mapping will be undertaken, with a focus on the shear zone systems that dissect the Mann Ranges, and subsequent metamorphic analysis supported by geochronology. Geochronology and metamorphic analysis will involve the use of high precision analytical tools (electron microprobe, laser ICP-MS, Sensitive High Resolution Ion Microprobe (SHRIMP) and thermal ionisation mass spectrometry).