Geological examination, mapping and sampling of the Mawson Volcano breccias at Shapeless Mountain and Allan Hills

A detailed study and sampling programme of the Mawson volcano breccia was carried out at Shapeless Mountain and on neighbouring Mistake Peak. Paleomagnetic measurements were used to determine the temperature of emplacement of dykes and flows of Mawson Volcano breccia in the Shapeless Mountain area. The lithology of the breccia varied quite considerable, both in clast and matrix composition, and sometimes this could be directly related to underlying or included rock types. Petrographic examination, chemical analysis and dating was carried out on the material sampled. In the following season, the study was extended to Mawson Breccia at Allan Hills and was revisited at Shapeless Mountain. Detailed mapping was completed on Shapeless Mountain, mechanical analysis of randomly chosen square meters of breccia was completed, clastic dykes were examined and samples were collected for chemical analysis, dating and palaeomagnetic study.