Attawapiskat kimberlite field mine was expected to produce of diamonds a year. 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
Lake Ellen Kimberlite till. Magnetic survey work done in 1956 depicts an elliptical positive anomaly long in an east–west direction and wide, which probably defines the limits of the pipe. The kimberlite is intruded into volcanic rocks of the Proterozoic Hemlock Formation. The exposed material is grayish green to reddish, iron stained highly weathered and consists of disaggregated rubbly fragments up to . It is generally accepted that the pipe was emplaced about 180 million years ago. The lake Ellen Kimberlite is popular with rock hounds as the classic indicator minerals (pyrope, magnesian ilmenite and chrome diopside) for kimberlite are easily found in