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
Volcanic rock strictly metavolcanic rocks. Volcanic rocks are among the most common rock types on Earth's surface, particularly in the oceans. On land, they are very common at plate boundaries and in flood basalt provinces. It has been estimated that volcanic rocks cover about 8% of the Earth's current land surface. Volcanic rocks are usually fine-grained or aphanitic to glass in texture. They often contain clasts of other rocks and phenocrysts. Phenocrysts are crystals that are larger than the matrix and are identifiable with the unaided eye. Rhomb porphyry is an example with large rhomb shaped phenocrysts embedded in a very fine