{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/4199"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/4199","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"A metamorphic and geochemical study of mafic rocks across the Pencksökket-Jutulstraumen Discontinuity, western Dronning Maud Land, East Antarctica","abstract":"A petrological and metamorphic comparison of Mesoproterozoic metabasic rocks on the easern margin of the Archaean Grunehogna Craton and the adjacent Maud Belt in western Dronning Maud Land, East Antarctica, revealed a difference in peak metamorphic conditions from T = ~275° to 730°C and P=2 to 10.7 kbar over a distance of only 30 km across a major glacial valley. The lower grade constraints were derived from average P-T calculations using THER-MOCALC and thermodynamic modeling of phase equilibria together with chlorite geothermometry. The high-grade P-T constraint for the westernmost part of the Maud Belt closest to the glacier, derived from hornblende-plagioclase thermometry and geobarometric calculations with a garnet amphibolite assemblage, is very similar to that reported for the eastern Maud Belt and, therefore, does not support the concept of a westward decreasing metamorphic field gradient as previously proposed. In conjunction with a recent geochronological study on the eastern Maud Belt, this study suggests that the inferred sub-glacial boundary between the Grunehogna Craton and the Maud Belt, known as the Pencksökket-Jutulstraumen Discontinuity, may represent a major thrust that developed during Pan-African orogenesis (possibly as the continuation of the East African Mozambique Belt into East Antarctica) prior to extension and its development as a normal listric fault or succession of fault slices during the Mesozoic break-up of Gondwana.","abstract_html":"A petrological and metamorphic comparison of Mesoproterozoic metabasic rocks on the easern margin of the Archaean Grunehogna Craton and the adjacent Maud Belt in western Dronning Maud Land, East Antarctica, revealed a difference in peak metamorphic conditions from T = ~275° to 730°C and P=2 to 10.7 kbar over a distance of only 30 km across a major glacial valley. The lower grade constraints were derived from average P-T calculations using THER-MOCALC and thermodynamic modeling of phase equilibria together with chlorite geothermometry. The high-grade P-T constraint for the westernmost part of the Maud Belt closest to the glacier, derived from hornblende-plagioclase thermometry and geobarometric calculations with a garnet amphibolite assemblage, is very similar to that reported for the eastern Maud Belt and, therefore, does not support the concept of a westward decreasing metamorphic field gradient as previously proposed. In conjunction with a recent geochronological study on the eastern Maud Belt, this study suggests that the inferred sub-glacial boundary between the Grunehogna Craton and the Maud Belt, known as the Pencksökket-Jutulstraumen Discontinuity, may represent a major thrust that developed during Pan-African orogenesis (possibly as the continuation of the East African Mozambique Belt into East Antarctica) prior to extension and its development as a normal listric fault or succession of fault slices during the Mesozoic break-up of Gondwana.","abstract_has_math":false,"creators":["Grosch, Eugene Gerald"],"institution":"Department of Geological Sciences","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Frimmel, Hartwig E"],"committee_chairs":[],"committee_members":[],"year":2005,"date_issued":"2005","date_published":"2005","updated_at":"2026-07-22T22:23:22Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/4199","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Frimmel, Hartwig E"]},{"key":"dc:creator","label":"Author","values":["Grosch, Eugene Gerald"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-07-30T17:26:17Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-07-30T17:26:17Z"]},{"key":"dc:date.issued","label":"Date","values":["2005"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Geological Sciences"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/4199"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Includes bibliographical references (leaves 89-102)."]},{"key":"dc:description.abstract","label":"Abstract","values":["A petrological and metamorphic comparison of Mesoproterozoic metabasic rocks on the easern margin of the Archaean Grunehogna Craton and the adjacent Maud Belt in western Dronning Maud Land, East Antarctica, revealed a difference in peak metamorphic conditions from T = ~275° to 730°C and P=2 to 10.7 kbar over a distance of only 30 km across a major glacial valley. The lower grade constraints were derived from average P-T calculations using THER-MOCALC and thermodynamic modeling of phase equilibria together with chlorite geothermometry. The high-grade P-T constraint for the westernmost part of the Maud Belt closest to the glacier, derived from hornblende-plagioclase thermometry and geobarometric calculations with a garnet amphibolite assemblage, is very similar to that reported for the eastern Maud Belt and, therefore, does not support the concept of a westward decreasing metamorphic field gradient as previously proposed. In conjunction with a recent geochronological study on the eastern Maud Belt, this study suggests that the inferred sub-glacial boundary between the Grunehogna Craton and the Maud Belt, known as the Pencksökket-Jutulstraumen Discontinuity, may represent a major thrust that developed during Pan-African orogenesis (possibly as the continuation of the East African Mozambique Belt into East Antarctica) prior to extension and its development as a normal listric fault or succession of fault slices during the Mesozoic break-up of Gondwana."]},{"key":"dc:title","label":"Title","values":["A metamorphic and geochemical study of mafic rocks across the Pencksökket-Jutulstraumen Discontinuity, western Dronning Maud Land, East Antarctica"]}]}],"canonical_facts":{"dc:contributor.advisor":["Frimmel, Hartwig E"],"dc:creator":["Grosch, Eugene Gerald"],"dc:date.accessioned":["2014-07-30T17:26:17Z"],"dc:date.available":["2014-07-30T17:26:17Z"],"dc:date.issued":["2005"],"dc:description":["Includes bibliographical references (leaves 89-102)."],"dc:description.abstract":["A petrological and metamorphic comparison of Mesoproterozoic metabasic rocks on the easern margin of the Archaean Grunehogna Craton and the adjacent Maud Belt in western Dronning Maud Land, East Antarctica, revealed a difference in peak metamorphic conditions from T = ~275° to 730°C and P=2 to 10.7 kbar over a distance of only 30 km across a major glacial valley. The lower grade constraints were derived from average P-T calculations using THER-MOCALC and thermodynamic modeling of phase equilibria together with chlorite geothermometry. The high-grade P-T constraint for the westernmost part of the Maud Belt closest to the glacier, derived from hornblende-plagioclase thermometry and geobarometric calculations with a garnet amphibolite assemblage, is very similar to that reported for the eastern Maud Belt and, therefore, does not support the concept of a westward decreasing metamorphic field gradient as previously proposed. In conjunction with a recent geochronological study on the eastern Maud Belt, this study suggests that the inferred sub-glacial boundary between the Grunehogna Craton and the Maud Belt, known as the Pencksökket-Jutulstraumen Discontinuity, may represent a major thrust that developed during Pan-African orogenesis (possibly as the continuation of the East African Mozambique Belt into East Antarctica) prior to extension and its development as a normal listric fault or succession of fault slices during the Mesozoic break-up of Gondwana."],"dc:identifier.uri":["http://hdl.handle.net/11427/4199"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Geological Sciences"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["A metamorphic and geochemical study of mafic rocks across the Pencksökket-Jutulstraumen Discontinuity, western Dronning Maud Land, East Antarctica"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc"]},"updated_at":"2026-07-22T22:23:22Z"}