Northern Alberta kimberlite province maar-style diatremes that have a vertical-walled volcanic crater of explosive origin, surrounded by a low rim of ejecta. Pyroclastic fall and surge are the two volcanic mechanisms of deposition. There are also deposits formed by hydraulic reworking and resedimentation of material from tephra cones and/or extra-crater fall and surge deposits. The NAKP volcanics, including the ML pipes, contain abundant lapilli and olivine supported in a fine-grained groundmass. Other minerals may include serpentine, clay minerals, carbonate minerals, phlogopite, ilmenite, perovskite, spinel, apatite, pyrite and, in some cases, diamonds. Northern Alberta kimberlite province The Northern Alberta Kimberlite Province (NAKP) consists of three
Grammy Award for Best Rock Performance Recording Academy's wish to decrease the list of categories and awards and to eliminate the distinctions between solo and duo/groups performances. The Academy argued that any distinction between these performances is difficult to make, as "four-fifths of rock acts are groups, and even solo rock acts tend to be backed by a band". From 2014, this category has also included hard rock performances that were previously screened in the Best Hard Rock Performance and Best Hard Rock/Metal Performance categories, which are now defunct. Grammy Award for Best Rock Performance The Grammy Award for Best Rock Performance is an award presented