The Temagami Magnetic Anomaly, also called the Temagami Anomaly or the Wanapitei Anomaly, is a large buried geologic structure in Ontario

Ontario

Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, stretching from Lake Wanapitei

Lake Wanapitei

Lake Wanapitei occupies a meteorite crater in Sudbury, Ontario, Canada. It is located near the large Sudbury meteorite crater but is not related to it....

 in the west to Bear Island

Bear Island (Lake Temagami)

Bear Island is an island in Lake Temagami of Northeastern Ontario, Canada. With an area of , it is the seconed largest island in Lake Temagami after Temagami Island...

 in Lake Temagami

Lake Temagami

Lake Temagami, formerly spelt as Lake Timagami, is a lake in Nipissing District in northeastern Ontario, Canada, situated approximately 80 km north of North Bay...

.

The magnetic anomaly

Magnetic anomaly

In geophysics, a magnetic anomaly is a local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying material...

 is located on the Canadian Shield

Canadian Shield

The Canadian Shield, also called the Laurentian Plateau, or Bouclier Canadien , is a vast geological shield covered by a thin layer of soil that forms the nucleus of the North American or Laurentia craton. It is an area mostly composed of igneous rock which relates to its long volcanic history...

 in the Temagami

Temagami, Ontario

Temagami, formerly spelt as Timagami, is a region and a municipality in northeastern Ontario, Canada, in the District of Nipissing with Lake Temagami at its heart....

 region of northeastern Ontario. The Aboriginal community of Teme-Augama Anishnabai

Teme-Augama Anishnabai

The Teme-Augama Anishnabai is the Aboriginal community of the Temagami First Nation. The TAA have trapped and hunted animals in the Temagami region of Canada for over 5,000 years...

 lies partly within the Temagami Magnetic Anomaly, including the Temagami First Nation

Temagami First Nation

Temagami First Nation is located on Bear Island, Lake Temagami, Ontario, Canada. It is home to a portion of the Aboriginal community, the Teme-Augama Anishnabai . The island is the seconed largest in Lake Temagami after Temagami Island...

 on Bear Island which is a portion of the Aboriginal community. Located nearby are a number of other geological structures, including the Sudbury Basin

Sudbury Basin

The Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is a major geologic structure in Ontario, Canada. It is the second-largest known impact crater or astrobleme on Earth, as well as one of the oldest....

, the Lake Wanapitei

Lake Wanapitei

Lake Wanapitei occupies a meteorite crater in Sudbury, Ontario, Canada. It is located near the large Sudbury meteorite crater but is not related to it....

 impact crater and the Temagami greenstone belt

Temagami greenstone belt

The Temagami greenstone belt, also known as the Temagami volcanic belt and the Temagami metavolcanic belt, is a small 2.7 billion year old greenstone belt in the Temagami region of Northeastern Ontario, Canada...

, although none of the structures are directly related to each other in the sense of resulting from the same geophysical processes.

Discovery and structure

The Temagami Magnetic Anomaly is egg shaped, 58 km (36 mi) long and 19 km (12 mi) wide. The central section has the greatest amplitude and an E-W strike. The western portion appears smoother in character while the eastern section is long and narrow. With an areal extent of 50 x 15 km, the Temagami Magnetic Anomaly reaches a magnitude of approximately 10,000 nanoteslas making it one of the largest positive anomalies in North America. It was discovered by a magnetic survey and a gravity survey.

The Temagami Magnetic Anomaly has striking similarities to the nearby Sudbury Basin

Sudbury Basin

The Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is a major geologic structure in Ontario, Canada. It is the second-largest known impact crater or astrobleme on Earth, as well as one of the oldest....

, which is one of the richest mining areas in the world. Its magnetic anomalies are very similar to the Sudbury Basin and so it could be a second metal-rich impact crater.