Petrogenesis of the tonalitic rocks from the Soer Rondane Mountains, East Antarctica

Tonalitic rocks (ca. 1000 Ma) from the Sor Rondane Mountains, East Antarctica, are characterized by relatively high Na_2O/K_2O (0.6-24), K/Rb (76-1638), Sr/Y (5-60), and (La/Yb) N (1-29), and relatively low CaO/ Na_2O (0.4-4) and low initial ^<87>Sr/^<86>Sr ratio (0.7024). They are chemi...

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Bibliographic Details
Main Authors: Yasuo Ikeda, Kazuyuki Shiraishi
Format: Report
Language:English
Published: Hokkaido University of Education at Kushiro/National Institute of Polar Research 1998
Subjects:
East Antarctica
MORB
slab
SOR Rondance Mountains
tonalite
Sor-Rondane
Sor Rondane Mountains
Antarc*
Antarctica
Polar geoscience
Online Access:https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3025
http://id.nii.ac.jp/1291/00003025/
https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3025&item_no=1&attribute_id=18&file_no=1
Description
Summary:Tonalitic rocks (ca. 1000 Ma) from the Sor Rondane Mountains, East Antarctica, are characterized by relatively high Na_2O/K_2O (0.6-24), K/Rb (76-1638), Sr/Y (5-60), and (La/Yb) N (1-29), and relatively low CaO/ Na_2O (0.4-4) and low initial ^<87>Sr/^<86>Sr ratio (0.7024). They are chemically similar to trondhjemites (1000 Ma) from the Lutzow-Holm Complex and to Archean tonalite-trondhjemites. Trace element modeling of the partial melting of MORB suggests that tonalitic rocks were derived by partial melting of a basaltic source material under garnet amphibolite stability P-T conditions. We suggest that a young hot subducting plate along the S0r Rondane Mountains at 1000 Ma may have reached elevated temperatures which initiated melting of the slab and generated the tonalitic rocks.

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