TY - JOUR
T1 - Petrogenesis of the late Archean syenitic Murdock Creek pluton, Kirkland Lake, Ontario
T2 - evidence for an extensional tectonic setting
AU - Rowins, S. M.
AU - Cameron, E. M.
AU - Lalonde, A. E.
AU - Ernst, R. E.
PY - 1993/1/1
Y1 - 1993/1/1
N2 - The Murdock Creek pluton has a spatial, temporal and possible genetic relationship to major Archean lode-gold deposits at Kirkland Lake in the Abitibi greenstone belt on Ontario. It is a compositionally zoned body. Quantitative modeling using Pearce element ratio diagrams demonstrates that the various rock-types were derived from a common parental magma by fractional crystallization principally of diopside, plagioclase, and alkali feldspar. Enhanced K2O, LILE and LREE contents, and depletions in Nb, Ta, and Ti, are geochemical characteristics of all units. These are typical of, but by no means unique to, igneous rocks formed in modern subduction-related island-arc settings. Moreover, the low Al2 O3, Na2O, SiO2, and high MgO whole-rock contents are more akin to alkaline rocks formed in rift environments far from subduction zones. Thus, recent tectonic models suggesting that Archean subduction processes are necessary for the genesis of these rocks may need revision. Gold mineralization in this important camp is shown to be consistent with an extensional tectonic regime. -from Authors
AB - The Murdock Creek pluton has a spatial, temporal and possible genetic relationship to major Archean lode-gold deposits at Kirkland Lake in the Abitibi greenstone belt on Ontario. It is a compositionally zoned body. Quantitative modeling using Pearce element ratio diagrams demonstrates that the various rock-types were derived from a common parental magma by fractional crystallization principally of diopside, plagioclase, and alkali feldspar. Enhanced K2O, LILE and LREE contents, and depletions in Nb, Ta, and Ti, are geochemical characteristics of all units. These are typical of, but by no means unique to, igneous rocks formed in modern subduction-related island-arc settings. Moreover, the low Al2 O3, Na2O, SiO2, and high MgO whole-rock contents are more akin to alkaline rocks formed in rift environments far from subduction zones. Thus, recent tectonic models suggesting that Archean subduction processes are necessary for the genesis of these rocks may need revision. Gold mineralization in this important camp is shown to be consistent with an extensional tectonic regime. -from Authors
UR - http://www.scopus.com/inward/record.url?scp=0027796633&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0027796633
SN - 0008-4476
VL - 31
SP - 219
EP - 244
JO - Canadian Mineralogist
JF - Canadian Mineralogist
IS - 1
ER -