Attawapiskat kimberlite field Attawapiskat kimberlite field The Attawapiskat kimberlite field is a field of kimberlite pipes located astride the Attawapiskat River in the Hudson Bay Lowlands, in Northern Ontario, Canada. It is thought to have formed about 180 million years ago in the Jurassic period when the North American Plate moved westward over a centre of upwelling magma called the New England hotspot, also referred to as the Great Meteor hotspot. Since June 26, 2008, the De Beers open pit Victor Diamond Mine has been in operation mining two pipes in the field at , about west of the community of Attawapiskat. The
Volcanic Explosivity Index assignment of a VEI for 7,742 volcanic eruptions that occurred during the Holocene (the last 11,700 years) which account for about 75% of the total known eruptions during the Holocene. Of these 7,742 eruptions, about 49% have a VEI of ≤ 2, and 90% have a VEI ≤ 3. Under the VEI, ash, lava, lava bombs, and ignimbrite are all treated alike. Density and vesicularity (gas bubbling) of the volcanic products in question is not taken into account. In contrast, the DRE (dense-rock equivalent) is sometimes calculated to give the actual amount of magma erupted. Another weakness of the VEI