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The Kapuskasing uplift: a deep crust natural laboratory
Author(s) -
Percival John A.
Publication year - 2019
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.14139
Subject(s) - crust , natural (archaeology) , geology , geophysics , paleontology
Interpretation of deep seismic features is largely unconstrained without knowledge of physical properties and structural history. For that reason, the Kapuskasing uplift of central Canada was an early target of Lithoprobe, aimed at calibrating seismic reflectivity in a terrane formed at depths >30 km. Previous work had shown sheet-like tonalitic and mafic (garnet-clinopyroxene-hornblende-plagioclase migmatites; 812kb, 700-850C) gneisses interlayered on scales of 100-1000m, with modeled acoustic velocity contrasts mimicking lower crustal reflectors. Structural features suggested passive rotation of subhorizontal layers to 30 dips along a brittle, southeast-verging thrust fault.