Determining Patterns in the Britannia Range of the Transantarctic Mountains

Presenter Information

Mindy Juergensen

Document Type

Oral Presentation

Campus where you would like to present

SURC Ballroom A

Start Date

17-5-2012

End Date

17-5-2012

Abstract

Antarctica is home to the Transantarctic Mountains (TAM), which extends over 2000 km. Located centrally within the TAM and approximately 80 km in length, Britannia Range provides a rare opportunity to understand how crust compresses, folds, and faults due to subduction from colliding plates. Rocks currently exposed consist of magmatic rocks emplaced by the Ross Orogeny during the Paleozoic Era. Thin sections of collected rock samples help to accurately examine and identify various types of igneous and metamorphosed migmatites, such as gneisses and schists. Generally, through hand specimen, and locally, through thin section, mineralogies and textures are examined to define each rock sample. Notably, quartz and epidote provide compelling evidence towards the depth at which these magmatic rocks cooled and deformed. The quartz grains exhibit ductile deformation (polygonal quartz) and high temperature deformation through subgrain rotation (~400-500 degrees Celsius), grain boundary migration (~500-550 degrees Celsius) and chessboard (>630 degrees Celsius) extinction textures. Epidote may appear in the rock samples as either a magmatic or metamorphic mineral. The formation depth of rocks containing epidote may be deduced by the crosscutting relationships between epidote and the surrounding minerals. Presently, data shows epidote most likely crystallized at pressures of ~0.8 to 0.5 GPa. The samples will be mapped on a satellite image to determine geological zone patterns within the Britannia Range. The history, evolution and deep metamorphism of the Britannia Range area may be better understood through examination of the mineralogical and textural compositions within the rock samples.

Poster Number

2

Faculty Mentor(s)

Audrey Huerta

Additional Mentoring Department

Geological Sciences

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May 17th, 2:00 PM May 17th, 4:30 PM

Determining Patterns in the Britannia Range of the Transantarctic Mountains

SURC Ballroom A

Antarctica is home to the Transantarctic Mountains (TAM), which extends over 2000 km. Located centrally within the TAM and approximately 80 km in length, Britannia Range provides a rare opportunity to understand how crust compresses, folds, and faults due to subduction from colliding plates. Rocks currently exposed consist of magmatic rocks emplaced by the Ross Orogeny during the Paleozoic Era. Thin sections of collected rock samples help to accurately examine and identify various types of igneous and metamorphosed migmatites, such as gneisses and schists. Generally, through hand specimen, and locally, through thin section, mineralogies and textures are examined to define each rock sample. Notably, quartz and epidote provide compelling evidence towards the depth at which these magmatic rocks cooled and deformed. The quartz grains exhibit ductile deformation (polygonal quartz) and high temperature deformation through subgrain rotation (~400-500 degrees Celsius), grain boundary migration (~500-550 degrees Celsius) and chessboard (>630 degrees Celsius) extinction textures. Epidote may appear in the rock samples as either a magmatic or metamorphic mineral. The formation depth of rocks containing epidote may be deduced by the crosscutting relationships between epidote and the surrounding minerals. Presently, data shows epidote most likely crystallized at pressures of ~0.8 to 0.5 GPa. The samples will be mapped on a satellite image to determine geological zone patterns within the Britannia Range. The history, evolution and deep metamorphism of the Britannia Range area may be better understood through examination of the mineralogical and textural compositions within the rock samples.