Birch Mountains kimberlite field shales interbedded with kimberlite at some of the diatremes are consistent with a Late Cretaceous age (Late Albian to Maastrichtian). The volcanic rocks of the BM field consist primarily of crater-facies pyroclastic kimberlite and resedimented kimberlite. They include massive layers, as well as bedded and graded layers of coarse lapilli alternating with layers of finer tuff. Lapilli and olivine phenocrysts are set in a grey-green matrix of serpentine, carbonate minerals (calcite, dolomite and magnesite) and clay minerals. Phlogopite, oxide minerals (ilmenite, perovskite and spinel), apatite and pyrite are also present. Diamonds and microdiamonds have been recovered from samples taken from
ARIA Award for Best Rock Album which consists of 1000 members from different areas of the music industry, and is given to a solo artist or group who is either from Australia or an Australian resident. The award for Best Rock Album has been won by Powderfinger the most time, with three wins, for: "Internationalist" (1999), "Odyssey Number Five" (2000) and "Vulture Street". In the following table, the winner is highlighted in a separate colour, and in boldface; the nominees are those that are not highlighted or in boldface. ARIA Award for Best Rock Album The ARIA Music Award for Best Rock Album, is an award