Premium
Structural evolution of the Makkovik Province, Labrador, Canada: Tectonic processes during 200 Myr at a Paleoproterozoic active margin
Author(s) -
Culshaw Nicholas,
Ketchum John,
Barr Sandra
Publication year - 2000
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/1999tc001156
Subject(s) - geology , terrane , pluton , archean , tectonics , craton , geochemistry , shear zone , rift , seismology
In the Makkovik Province, the structures and plutonic rocks of the reworked southern edge of the Archean Nain craton (parautochthon) and an adjacent juvenile domain form a spatially concentrated record of ∼ 200 Ma at a Paleoproterozoic active margin. D1 thin‐ and thick‐skinned structures, formed during terrane collision before ca. 1896 Ma, were nearly erased by D2 transpressive structures present across the entire parautochthon that had been thermally softened by emplacement of arc plutons at ca. 1895–1870 Ma. D3 transpressive inversion of a back arc rift and D4 strike‐slip shearing formed structures at the oceanward margin of the parautochthon and were responses to events in the active arc that was now widely separated from the parautochthon by accreted terranes. The tectonic isolation of the parautochthon ended by the time of D5 (ca. 1740–1710 Ma) and D6 with the reappearance there of granite and low‐grade shear zones. Structural and plutonic style varied at each stage, primarily controlled by the crustal level attained.