U-Pb (zircon) geochronologic analyses for rocks of the Transantarctic Mountains (Table 4.3-1)

The Byrd Glacier discontinuity us a major boundary crossing the Ross Orogen, with crystalline rocks to the north and primarily sedimentary rocks to the south. Most models for the tectonic development of the Ross Orogen in the central Transantarctic Mountains consits of two-dimensional transects acro...

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Bibliographic Details
Main Authors: Stump, Edmund, Gootee, Brian, Lauria, Mary-Lou
Format: Dataset
Language:English
Published: PANGAEA 2007
Subjects:
Age
dated
error
relative
Error correction
Laser-ablation mass-spectrometry
Lead-206/Lead-204 ratio
Lead-206/Lead-207 ratio
Lead-206/Uranium-238 ratio
Lead-207/Uranium-235 ratio
ORDINAL NUMBER
OUTCROP
Outcrop sample
Ramsey_Glacier
Sample code/label
Transantarctic Mountains
Uranium
Uranium/Thorium ratio
East Antarctica
Byrd
Beardmore
Byrd Glacier
Britannia
Britannia Range
Antarc*
Antarctica
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.611703
https://doi.org/10.1594/PANGAEA.611703
Description
Summary:The Byrd Glacier discontinuity us a major boundary crossing the Ross Orogen, with crystalline rocks to the north and primarily sedimentary rocks to the south. Most models for the tectonic development of the Ross Orogen in the central Transantarctic Mountains consits of two-dimensional transects across the belt, but do not adress the major longitudinal contrast at Byrd Glacier. This paper presents a tectonic model centering on the Byrd Glacier discontinuity. Rifting in the Neoproterozoic producede a crustal promontory in the craton margin to the north of Byrd Glacier. Oblique convergence of the terrane (Beardmore microcontinent) during the latest Neroproterozoic and Early Cambrian was accompanied by subduction along the craton margin of East Antarctica. New data presented herein in the support of this hypothesis are U-Pb dates of 545.7 ± 6.8 Ma and 531.0 ± 7.5 Ma on plutonic rocks from the Britannia Range, subduction stepped out, and Byrd Glacier. After docking of the terrane, subduction stepped out, and Byrd Group was deposited during the Atdabanian-Botomian across the inner margin of the terrane. Beginning in the upper Botomian, reactivation of the sutured boundaries of the terrane resulted in an outpouring of clastic sediment and folding and faulting of the Byrd Group.

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