the canadian shield was formed in the 600 to 1200 million years old era.
when was the canadian shield formed what era?
600 to 1200 million years old
the canadian shield is a collage of archean plates and accreted juvenile arc terranes and sedimentary basins of the proterozoic eon that were progressively amalgamated during the interval 2.45 to 1.24 ga, with the most substantial growth period occurring during the trans-hudson orogeny, between ca. 1.90 to 1.80 ga. the canadian shield was the first part of north america to be permanently elevated above sea level and has remained almost wholly untouched by successive encroachments of the sea upon the continent. it is the earth's greatest area of exposed archean rock. the metamorphic base rocks are mostly from the precambrian (between 4.5 billion and 540 million years ago) and have been repeatedly uplifted and eroded. today it consists largely of an area of low relief above sea level with a few monadnocks and low mountain ranges (including the torngat and laurentian mountains) probably eroded from the plateau during the cenozoic era. during the pleistocene epoch, continental ice sheets depressed the land surface creating hudson bay, scooped out thousands of lake basins, and carried away much of the region's soil.
canadian shield
section::::canadian shield.





























about 61% of ontario is covered by the canadian shield, mostly with precambrian rock. the canadian shield spans much of northern ontario and is subdivided into three main geological provinces; the superior, southern and grenville. 





























section::::canadian shield.:superior province.





























the superior craton or superior province is an archean craton. it is a 160-mile thick section of stable continental crust formed beginning (4.031 billion years ago-present) which forms the core of the canadian shield lying north of lake superior for which it is named. it is located roughly north and west of sudbury
geology of ontario