{"id":{"repo_id":"unm","oai_identifier":"oai:digitalrepository.unm.edu:eps_etds-1096"},"canonical_url":"https://search.dev.ndltd.org/etd/unm/oai:digitalrepository.unm.edu:eps_etds-1096","repository":{"repo_id":"unm","name":"University of New Mexico","base_url":"https://digitalrepository.unm.edu/do/oai/"},"display":{"title":"Investigating evidence of high frequency glacial eustacy in the Lower Mississippian (Tournasian) Lodgepole Formation of southwest Montana : insights from conodont oxygen isotopes","abstract":"This study focuses on high-frequency, subtidal-carbonate cycles (1-8 m thick) within the Woodhurst Member of the Lower Mississippian Lodgepole Formation of southwest Montana. We combined conodont-oxygen isotopes (δ18Oapatite¬) and carbonate-carbon isotopes (δ13Ccarb) with cyclostratigraphy of Woodhurst cycles to test the hypothesis that the cycles developed in response to glacial eustasy, evaluate the timing and initiation of the Late Paleozoic Ice Age (LPIA), and to better understand the carbon budget in response to cycle formation. δ18Oapatite trends across targeted cycles support the hypothesis of glacial eustatic origins along with cooling surface seawater temperatures. High-resolution δ13Ccarb analysis of whole-rock limestones within eleven cycles reveal invariant or nonsystematic δ13Ccarb trends, but the long term trend confirms a major positive excursion reported in previous studies of coeval deposits, values peak at ~ 7.5 ° in the upper S. isosticha conodont Zone.","abstract_html":"This study focuses on high-frequency, subtidal-carbonate cycles (1-8 m thick) within the Woodhurst Member of the Lower Mississippian Lodgepole Formation of southwest Montana. We combined conodont-oxygen isotopes (δ18Oapatite¬) and carbonate-carbon isotopes (δ13Ccarb) with cyclostratigraphy of Woodhurst cycles to test the hypothesis that the cycles developed in response to glacial eustasy, evaluate the timing and initiation of the Late Paleozoic Ice Age (LPIA), and to better understand the carbon budget in response to cycle formation. δ18Oapatite trends across targeted cycles support the hypothesis of glacial eustatic origins along with cooling surface seawater temperatures. High-resolution δ13Ccarb analysis of whole-rock limestones within eleven cycles reveal invariant or nonsystematic δ13Ccarb trends, but the long term trend confirms a major positive excursion reported in previous studies of coeval deposits, values peak at ~ 7.5 ° in the upper S. isosticha conodont Zone.","abstract_has_math":false,"creators":["Wallace, Zachary"],"institution":null,"degree_name":"Earth and Planetary Sciences","degree_level":"Masters","degree_discipline":"Department of Earth and Planetary Sciences","degree_department":null,"school":null,"contributors":["Elrick, Maya","Atudorei, Viorel","Fawcett, Peter"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-08-30T07:00:00Z","date_published":"2011-08-30T07:00:00Z","updated_at":"2026-07-24T05:26:22Z","subjects":["Early Mississippian","Conodonts","Lodgepole Formation","Cycles"],"languages":["English"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalrepository.unm.edu/eps_etds/97"],"render_values":[{"text":"https://digitalrepository.unm.edu/eps_etds/97","href":"https://digitalrepository.unm.edu/eps_etds/97","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/1928/13115","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Elrick, Maya","Atudorei, Viorel","Fawcett, Peter"]},{"key":"dc:creator","label":"Author","values":["Wallace, Zachary"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Department of Earth and Planetary Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters","Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Earth and Planetary Sciences"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Early Mississippian","Conodonts","Lodgepole Formation","Cycles"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/1928/13115","https://digitalrepository.unm.edu/eps_etds/97"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This study focuses on high-frequency, subtidal-carbonate cycles (1-8 m thick) within the Woodhurst Member of the Lower Mississippian Lodgepole Formation of southwest Montana. We combined conodont-oxygen isotopes (δ18Oapatite¬) and carbonate-carbon isotopes (δ13Ccarb) with cyclostratigraphy of Woodhurst cycles to test the hypothesis that the cycles developed in response to glacial eustasy, evaluate the timing and initiation of the Late Paleozoic Ice Age (LPIA), and to better understand the carbon budget in response to cycle formation. δ18Oapatite trends across targeted cycles support the hypothesis of glacial eustatic origins along with cooling surface seawater temperatures. High-resolution δ13Ccarb analysis of whole-rock limestones within eleven cycles reveal invariant or nonsystematic δ13Ccarb trends, but the long term trend confirms a major positive excursion reported in previous studies of coeval deposits, values peak at ~ 7.5 ° in the upper S. isosticha conodont Zone."]},{"key":"dc:title","label":"Title","values":["Investigating evidence of high frequency glacial eustacy in the Lower Mississippian (Tournasian) Lodgepole Formation of southwest Montana : insights from conodont oxygen isotopes"]}]}],"canonical_facts":{"dc:contributor":["Elrick, Maya","Atudorei, Viorel","Fawcett, Peter"],"dc:creator":["Wallace, Zachary"],"dc:description.abstract":["This study focuses on high-frequency, subtidal-carbonate cycles (1-8 m thick) within the Woodhurst Member of the Lower Mississippian Lodgepole Formation of southwest Montana. We combined conodont-oxygen isotopes (δ18Oapatite¬) and carbonate-carbon isotopes (δ13Ccarb) with cyclostratigraphy of Woodhurst cycles to test the hypothesis that the cycles developed in response to glacial eustasy, evaluate the timing and initiation of the Late Paleozoic Ice Age (LPIA), and to better understand the carbon budget in response to cycle formation. δ18Oapatite trends across targeted cycles support the hypothesis of glacial eustatic origins along with cooling surface seawater temperatures. High-resolution δ13Ccarb analysis of whole-rock limestones within eleven cycles reveal invariant or nonsystematic δ13Ccarb trends, but the long term trend confirms a major positive excursion reported in previous studies of coeval deposits, values peak at ~ 7.5 ° in the upper S. isosticha conodont Zone."],"dc:identifier":["http://hdl.handle.net/1928/13115","https://digitalrepository.unm.edu/eps_etds/97"],"dc:language":["English"],"dc:subject":["Early Mississippian","Conodonts","Lodgepole Formation","Cycles"],"dc:title":["Investigating evidence of high frequency glacial eustacy in the Lower Mississippian (Tournasian) Lodgepole Formation of southwest Montana : insights from conodont oxygen isotopes"],"thesis:degree_discipline":["Department of Earth and Planetary Sciences"],"thesis:degree_level":["Masters","Thesis"],"thesis:degree_name":["Earth and Planetary Sciences"]},"updated_at":"2026-07-24T05:26:22Z"}