Open AccessNeoproterozoic metamorphic evolution of the Isbjørnhamna Group rocks from south‐western Svalbard
Author(s) -
Majka Jaroslaw,
Czerny Jerzy,
Mazur Stanislaw,
Holm Daniel K.,
Manecki Maciej
Publication year - 2010
Publication title -
polar research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.508
H-Index - 49
eISSN - 1751-8369
pISSN - 0800-0395
DOI - 10.1111/j.1751-8369.2010.00186.x
Subject(s) - geothermobarometry , geology , metamorphism , metamorphic rock , metamorphic facies , schist , geochemistry , facies , group (periodic table) , biotite , petrology , geomorphology , paleontology , quartz , chemistry , organic chemistry , structural basin
A metamorphosed volcano‐sedimentary complex constitutes the Caledonian basement in the south‐western part of Wedel Jarlsberg Land, Svalbard. Field, textural and previous thermochronologic data indicate a weak, localized metamorphic Caledonian overprint (M2). Deformed M1 isograds and variation in pressure–temperature estimates indicate a pervasive Neoproterozoic amphibolite‐facies metamorphism that pre‐dates large‐scale Caledonian age folding. Garnet–biotite and garnet–Al silicate–plagioclase (GASP) geothermobarometry of the Isbjørnhamna Group mica schists, and their comparison with the K 2 O–FeO–MgO–Al 2 O 3 –SiO 2 –H 2 O (KFMASH) petrogenetic grid, indicates a peak pressure of ca. 11 kbar, and a peak temperature of ca. 670°C during M1 metamorphism. A cooling rate of ca. 5°C My −1 is estimated on the basis of geothermobarometry and the available U–Th–total Pb and Ar–Ar data.