Buffalo Head Hills kimberlite field grained, and well bedded, with high bedding angles. The reworked kimberlite is well sorted, distinctly bedded, and contains abraded olivine grains. Multiple layers of pyroclastic and reworked kimberlite separated by layers of marine mudstone are present at some pipes. These represent a series of discrete kimberlite eruption events separated by quiescent periods during which the muds were deposited. The majority of the BHH kimberlites are diamondiferous, in contrast to those of the Birch Mountains kimberlite field to the northeast which are mostly barren of diamonds. Based on petrography and whole-rock geochemistry, the BHH pipes are classed as Group 1A kimberlites.
Grammy Award for Best Rock Performance Grammy Award for Best Rock Performance The Grammy Award for Best Rock Performance is an award presented at the Grammy Awards, a ceremony that was established in 1958 and originally called the Gramophone Awards. According to the 54th Grammy Awards description guide it is designed for solo, duo/groups or collaborative (vocal or instrumental) rock recordings and is limited to singles or tracks only. This award combines the previous categories for Best Solo Rock Vocal Performance, Best Rock Performance by a Duo or Group with Vocal and Best Rock Instrumental Performance. The restructuring of these categories was a result of the