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The Labrador Trough or the New Quebec Orogen is a long and wide geologic belt in Canada, extending south-southeast from Ungava Bay through Quebec and Labrador. The trough is a linear belt of sedimentary and volcanic rocks which developed in an Early Proterozoic rift basin. To the west is the Archean Superior Craton. To the east are the rocks of the Archean Rae Craton. The sedimentary rocks and volcanics of the Labrador Trough were intensely deformed and subjected to high grade metamorphism along with the Churchill terrain during the Trans-Hudson orogeny.〔Kearey, Philip and Frederick Vine, ''Global Tectonics,'' Wiley-Blackwell, 2nd ed., 1996, pp. 279-281 ISBN 978-0-86542-924-6〕 It is a northeast extension of the Circum-Superior Belt and is terminated to the south by the Grenville Front Tectonic Zone.〔Green, J. C., ''Proterozoic Rifts,'' in Condie, K. C., ed., ''Proterozoic Crustal Evolution,'' Elsevier, 1993, Ch. 3, pp. 102-104 ISBN 978-0-444-88782-5〕 Radiometric dates of 1883-1870 Ma are reported for mafic, ultramafic, carbonatite and lamprophyre intrusions within the Trough.〔(【引用サイトリンク】publisher=Ernst, Richard E. )〕 It is a large iron ore belt developed on banded iron formations and has had mining operations since 1954.〔(Iron Deposits of the Labrador Trough )〕 At least two large magmatic events occurred in the Labrador Trough. The first event 2,170 million years ago engulfed an area of and the second 1,880 million years ago covered a similar area of . ==See also== *Volcanism of Eastern Canada 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「Labrador Trough」の詳細全文を読む スポンサード リンク
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