{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/43526"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/43526","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Late Cenozoic Exhumation in a Transpressional Setting: Fairweather Range, Alaska","abstract":"Deformation in southern Alaska is controlled by the accretion and partial subduction of the Yakutat terrane as margin-parallel motion transitions to subduction. Recent studies have shown that deformation in the St. Elias orogen, at the northern end of the terrane, accommodates a large portion of convergence, but deformation at the eastern and southern margins remains more poorly constrained. Rapid recent sedimentation (> 1cm/yr) and glacio-isostatic uplift rates (> 3 cm/yr) in the Fairweather corridor highlight short-term vertical deformation at the eastern margin; however, the relationship between these rates and long-term deformation is less well known. New low-temperature cooling ages are reported along the eastern flank of the St. Elias orogen, placing constraints on vertical deformation over the past few million years. Young cooling ages (< 3 Ma) occur in a broad zone, extending along the onshore length of the strike-slip Fairweather fault. These ages indicate that protracted convergence has been accommodated in the Fairweather corridor. Average (~1 mm/yr) and peak (~3 mm/yr) late Cenozoic exhumation rates are similar to rates to the north, and suggest that the orogen is actually boomerang-shaped in map view. If ~1 mm/yr exhumation has been steady, the onset of rapid exhumation is constrained to post-12 Ma, but likely occurred at 5 Ma with changes in climate and plate obliquity. Although cooling ages reveal no coherent regional pattern relative to known structures, they indicate the margin accommodates a significant component of pure shear and is slip-partitioned. The resolved magnitude of convergence in the Fairweather corridor also indicates that Yakutat terrane motion is rotated from Pacific plate motion, and likely requires significant slip on the Transition fault at the southern edge of the Yakutat terrane. Although million-year exhumation rates are rapid, they are slower than short-term rates related to deglaciation.","abstract_html":"Deformation in southern Alaska is controlled by the accretion and partial subduction of the Yakutat terrane as margin-parallel motion transitions to subduction. Recent studies have shown that deformation in the St. Elias orogen, at the northern end of the terrane, accommodates a large portion of convergence, but deformation at the eastern and southern margins remains more poorly constrained. Rapid recent sedimentation (&gt; 1cm/yr) and glacio-isostatic uplift rates (&gt; 3 cm/yr) in the Fairweather corridor highlight short-term vertical deformation at the eastern margin; however, the relationship between these rates and long-term deformation is less well known. New low-temperature cooling ages are reported along the eastern flank of the St. Elias orogen, placing constraints on vertical deformation over the past few million years. Young cooling ages (&lt; 3 Ma) occur in a broad zone, extending along the onshore length of the strike-slip Fairweather fault. These ages indicate that protracted convergence has been accommodated in the Fairweather corridor. Average (~1 mm/yr) and peak (~3 mm/yr) late Cenozoic exhumation rates are similar to rates to the north, and suggest that the orogen is actually boomerang-shaped in map view. If ~1 mm/yr exhumation has been steady, the onset of rapid exhumation is constrained to post-12 Ma, but likely occurred at 5 Ma with changes in climate and plate obliquity. Although cooling ages reveal no coherent regional pattern relative to known structures, they indicate the margin accommodates a significant component of pure shear and is slip-partitioned. The resolved magnitude of convergence in the Fairweather corridor also indicates that Yakutat terrane motion is rotated from Pacific plate motion, and likely requires significant slip on the Transition fault at the southern edge of the Yakutat terrane. Although million-year exhumation rates are rapid, they are slower than short-term rates related to deglaciation.","abstract_has_math":false,"creators":["McAleer, Ryan Joseph"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Geosciences","degree_department":"Geosciences","school":null,"contributors":[],"advisors":[],"committee_chairs":["Spotila, James A."],"committee_members":["Hole, John A.","Law, Richard D."],"year":2006,"date_issued":"2006-06-28","date_published":"2006-06-28","updated_at":"2026-07-22T22:20:21Z","subjects":["glacial erosion","exhumation","Alaska","AHe dating","transpression"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-07032006-104340"],"render_values":[{"text":"etd-07032006-104340","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/43526","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Spotila, James A."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Hole, John A.","Law, Richard D."]},{"key":"dc:contributor.department","label":"Department","values":["Geosciences"]},{"key":"dc:creator","label":"Author","values":["McAleer, Ryan Joseph"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:39:29Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:39:29Z","2006-09-06"]},{"key":"dc:date.issued","label":"Date","values":["2006-06-28"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geosciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["glacial erosion","exhumation","Alaska","AHe dating","transpression"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-07032006-104340"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/43526"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Deformation in southern Alaska is controlled by the accretion and partial subduction of the Yakutat terrane as margin-parallel motion transitions to subduction. Recent studies have shown that deformation in the St. Elias orogen, at the northern end of the terrane, accommodates a large portion of convergence, but deformation at the eastern and southern margins remains more poorly constrained. Rapid recent sedimentation (> 1cm/yr) and glacio-isostatic uplift rates (> 3 cm/yr) in the Fairweather corridor highlight short-term vertical deformation at the eastern margin; however, the relationship between these rates and long-term deformation is less well known. New low-temperature cooling ages are reported along the eastern flank of the St. Elias orogen, placing constraints on vertical deformation over the past few million years. Young cooling ages (< 3 Ma) occur in a broad zone, extending along the onshore length of the strike-slip Fairweather fault. These ages indicate that protracted convergence has been accommodated in the Fairweather corridor. Average (~1 mm/yr) and peak (~3 mm/yr) late Cenozoic exhumation rates are similar to rates to the north, and suggest that the orogen is actually boomerang-shaped in map view. If ~1 mm/yr exhumation has been steady, the onset of rapid exhumation is constrained to post-12 Ma, but likely occurred at 5 Ma with changes in climate and plate obliquity. Although cooling ages reveal no coherent regional pattern relative to known structures, they indicate the margin accommodates a significant component of pure shear and is slip-partitioned. The resolved magnitude of convergence in the Fairweather corridor also indicates that Yakutat terrane motion is rotated from Pacific plate motion, and likely requires significant slip on the Transition fault at the southern edge of the Yakutat terrane. Although million-year exhumation rates are rapid, they are slower than short-term rates related to deglaciation."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Late Cenozoic Exhumation in a Transpressional Setting: Fairweather Range, Alaska"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Spotila, James A."],"dc:contributor.committeemember":["Hole, John A.","Law, Richard D."],"dc:contributor.department":["Geosciences"],"dc:creator":["McAleer, Ryan Joseph"],"dc:date.accessioned":["2014-03-14T21:39:29Z"],"dc:date.available":["2014-03-14T21:39:29Z","2006-09-06"],"dc:date.issued":["2006-06-28"],"dc:description.abstract":["Deformation in southern Alaska is controlled by the accretion and partial subduction of the Yakutat terrane as margin-parallel motion transitions to subduction. Recent studies have shown that deformation in the St. Elias orogen, at the northern end of the terrane, accommodates a large portion of convergence, but deformation at the eastern and southern margins remains more poorly constrained. Rapid recent sedimentation (> 1cm/yr) and glacio-isostatic uplift rates (> 3 cm/yr) in the Fairweather corridor highlight short-term vertical deformation at the eastern margin; however, the relationship between these rates and long-term deformation is less well known. New low-temperature cooling ages are reported along the eastern flank of the St. Elias orogen, placing constraints on vertical deformation over the past few million years. Young cooling ages (< 3 Ma) occur in a broad zone, extending along the onshore length of the strike-slip Fairweather fault. These ages indicate that protracted convergence has been accommodated in the Fairweather corridor. Average (~1 mm/yr) and peak (~3 mm/yr) late Cenozoic exhumation rates are similar to rates to the north, and suggest that the orogen is actually boomerang-shaped in map view. If ~1 mm/yr exhumation has been steady, the onset of rapid exhumation is constrained to post-12 Ma, but likely occurred at 5 Ma with changes in climate and plate obliquity. Although cooling ages reveal no coherent regional pattern relative to known structures, they indicate the margin accommodates a significant component of pure shear and is slip-partitioned. The resolved magnitude of convergence in the Fairweather corridor also indicates that Yakutat terrane motion is rotated from Pacific plate motion, and likely requires significant slip on the Transition fault at the southern edge of the Yakutat terrane. Although million-year exhumation rates are rapid, they are slower than short-term rates related to deglaciation."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-07032006-104340"],"dc:identifier.uri":["http://hdl.handle.net/10919/43526"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["glacial erosion","exhumation","Alaska","AHe dating","transpression"],"dc:title":["Late Cenozoic Exhumation in a Transpressional Setting: Fairweather Range, Alaska"],"dc:type":["Thesis"],"thesis:degree_discipline":["Geosciences"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:21Z"}