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The Great Lakes tectonic zone is bounded by South Dakota at its tip and heads northeast to south of Duluth, Minnesota, then heads east through northern Wisconsin, Marquette, Michigan, and then trends more northeasterly to skim the northern-most shores of lakes Michigan and Huron before ending in the Sudbury, Ontario, Canada, area. During the Late Archean Era the Algoman orogeny added landmass to the Superior province by volcanic activity and continental collision along a boundary that stretches from present-day South Dakota, U.S., into the Lake Huron region near Sudbury, Ontario, Canada. This crustal boundary is the Great Lakes tectonic zone. It is long, and separates the older Archean gneissic terrane to the south from younger Late Archean greenstone-granite terrane to the north. The zone is characterized by active compression during the Algoman orogeny (about ), a pulling-apart (extensional) tectonics (2,450 to 2,100 million years ago), a second compression during the Penokean orogeny (1,900 to 1,850 million years ago), a second extension during Middle Proterozoic time (1,600 million years ago) and minor reactivation during Phanerozoic time (the past 500 million years). Collision began along the Great Lakes tectonic zone (GLTZ) with the Algoman mountain-building event and continued for tens of millions of years. During the formation of the GLTZ, the gneissic Minnesota River Valley subprovince was thrust up onto the Superior province's edge as it consumed the Superior province's oceanic crust. Fragmentation of the Kenorland supercontinent began and was completed by . The Wyoming province is the continental landmass that is hypothesized to have rifted away from the southern Superior province portion of Kenorland, before moving rapidly west and docking with the Laurentia supercontinent 1,850 to 1,715 million years ago. Sedimentation from the GLTZ-rifting environment continued into the Penokean orogeny, which is the next major tectonic event in the Great Lakes region. Several earthquakes have been documented in Minnesota, Michigan's Upper Peninsula and Sudbury in the last 120 years along the GLTZ. ==Location== During the Late Archean Eon the Algoman orogeny – which occurred about – added landmass through volcanic activity and continental collision along a boundary that stretches from present-day South Dakota, U.S., into the Sudbury, Ontario, Canada, region. The farthest west into South Dakota is 99°W, which is about from the Minnesota – South Dakota border. This crustal boundary is the Great Lakes tectonic zone (GLTZ). It is a long paleosuture that separates the more than 3,000-million-year-old Archean gneissic terrane to the south – Minnesota River Valley subprovince – from the 2,700-million-year-old Late Archean greenstone-granite terrane to the north – Wawa Subprovince of the Superior province. The GLTZ is wide. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Great Lakes tectonic zone」の詳細全文を読む スポンサード リンク
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