{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/34704"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/34704","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Petrogenesis and geochemistry of kyanite-bearing pegmatites in the Buncombe Pegmatite District, North Carolina","abstract":"Kyanite is generally considered to be a product of metamorphism. This study investigates a set of kyanite-bearing pegmatites that represent a case in which kyanite crystallized directly from melt. The pegmatites intrude spinel orthopyroxene hornblendite in the Buncombe Pegmatite District in the Eastern Blue Ridge of North Carolina. One site was studied in detail and survey studies of two other occurrences were made. The pegmatites contain quartz, large euhedral crystals of plagioclase, biotite, and kyanite, as well as apatite, muscovite, tourmaline, and microscopic primary sillimanite. Potassium feldspar is notably absent. One site, the Thomas Mine, was examined in detail in order to determine the mode of occurrence for these rocks. Excavation revealed pegmatite with two texturally and mineralogically distinct zones. Biotite-rich rocks surrounding the pegmatite indicate strongly potassic alteration of the host hornblendite. Trace element data obtained for kyanite and biotite from the pegmatite show clear patterns related to chemical fractionation of these components during crystallization. Major element geochemistry of the pegmatite and host ,I rocks are consistent with magmatic intrusion. Reaction of the pegmatite melt with the host rocks led to the formation of large amounts of biotite, and depleted the melt in potassium. The remaining melt became saturated in aluminum silicate and crystallized kyanite and sillimanite. Wallrock assemblages, fluid inclusions in pegmatite quartz, the coexistence of kyanite and sillimanite as primary phases, and geothermobarometry on nearby unaltered rocks all indicate conditions of formation of approximately 600-800 MPa and 625-675°C, near those of peak metamorphism for the region.","abstract_html":"Kyanite is generally considered to be a product of metamorphism. This study investigates a set of kyanite-bearing pegmatites that represent a case in which kyanite crystallized directly from melt. The pegmatites intrude spinel orthopyroxene hornblendite in the Buncombe Pegmatite District in the Eastern Blue Ridge of North Carolina. One site was studied in detail and survey studies of two other occurrences were made. The pegmatites contain quartz, large euhedral crystals of plagioclase, biotite, and kyanite, as well as apatite, muscovite, tourmaline, and microscopic primary sillimanite. Potassium feldspar is notably absent. One site, the Thomas Mine, was examined in detail in order to determine the mode of occurrence for these rocks. Excavation revealed pegmatite with two texturally and mineralogically distinct zones. Biotite-rich rocks surrounding the pegmatite indicate strongly potassic alteration of the host hornblendite. Trace element data obtained for kyanite and biotite from the pegmatite show clear patterns related to chemical fractionation of these components during crystallization. Major element geochemistry of the pegmatite and host ,I rocks are consistent with magmatic intrusion. Reaction of the pegmatite melt with the host rocks led to the formation of large amounts of biotite, and depleted the melt in potassium. The remaining melt became saturated in aluminum silicate and crystallized kyanite and sillimanite. Wallrock assemblages, fluid inclusions in pegmatite quartz, the coexistence of kyanite and sillimanite as primary phases, and geothermobarometry on nearby unaltered rocks all indicate conditions of formation of approximately 600-800 MPa and 625-675°C, near those of peak metamorphism for the region.","abstract_has_math":false,"creators":["Wood, Keith Yates"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Geology","degree_department":"Geology","school":null,"contributors":[],"advisors":[],"committee_chairs":["Tracy, Robert J.","Bodnar, Robert J."],"committee_members":["Wise, Michael A."],"year":1996,"date_issued":"1996-08-01","date_published":"1996-08-01","updated_at":"2026-07-22T22:19:19Z","subjects":["pegmatite","kyanite","magmatic","biotite"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08222008-063115"],"render_values":[{"text":"etd-08222008-063115","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/34704","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Tracy, Robert J.","Bodnar, Robert J."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Wise, Michael A."]},{"key":"dc:contributor.department","label":"Department","values":["Geology"]},{"key":"dc:creator","label":"Author","values":["Wood, Keith Yates"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:44:01Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:44:01Z","2010-10-04"]},{"key":"dc:date.issued","label":"Date","values":["1996-08-01"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geology"]},{"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":["pegmatite","kyanite","magmatic","biotite"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"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-08222008-063115"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/34704"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Kyanite is generally considered to be a product of metamorphism. This study investigates a set of kyanite-bearing pegmatites that represent a case in which kyanite crystallized directly from melt. The pegmatites intrude spinel orthopyroxene hornblendite in the Buncombe Pegmatite District in the Eastern Blue Ridge of North Carolina. One site was studied in detail and survey studies of two other occurrences were made. The pegmatites contain quartz, large euhedral crystals of plagioclase, biotite, and kyanite, as well as apatite, muscovite, tourmaline, and microscopic primary sillimanite. Potassium feldspar is notably absent. One site, the Thomas Mine, was examined in detail in order to determine the mode of occurrence for these rocks. Excavation revealed pegmatite with two texturally and mineralogically distinct zones. Biotite-rich rocks surrounding the pegmatite indicate strongly potassic alteration of the host hornblendite. Trace element data obtained for kyanite and biotite from the pegmatite show clear patterns related to chemical fractionation of these components during crystallization. Major element geochemistry of the pegmatite and host ,I rocks are consistent with magmatic intrusion. Reaction of the pegmatite melt with the host rocks led to the formation of large amounts of biotite, and depleted the melt in potassium. The remaining melt became saturated in aluminum silicate and crystallized kyanite and sillimanite. Wallrock assemblages, fluid inclusions in pegmatite quartz, the coexistence of kyanite and sillimanite as primary phases, and geothermobarometry on nearby unaltered rocks all indicate conditions of formation of approximately 600-800 MPa and 625-675°C, near those of peak metamorphism for the region."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Petrogenesis and geochemistry of kyanite-bearing pegmatites in the Buncombe Pegmatite District, North Carolina"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Tracy, Robert J.","Bodnar, Robert J."],"dc:contributor.committeemember":["Wise, Michael A."],"dc:contributor.department":["Geology"],"dc:creator":["Wood, Keith Yates"],"dc:date.accessioned":["2014-03-14T20:44:01Z"],"dc:date.available":["2014-03-14T20:44:01Z","2010-10-04"],"dc:date.issued":["1996-08-01"],"dc:description.abstract":["Kyanite is generally considered to be a product of metamorphism. This study investigates a set of kyanite-bearing pegmatites that represent a case in which kyanite crystallized directly from melt. The pegmatites intrude spinel orthopyroxene hornblendite in the Buncombe Pegmatite District in the Eastern Blue Ridge of North Carolina. One site was studied in detail and survey studies of two other occurrences were made. The pegmatites contain quartz, large euhedral crystals of plagioclase, biotite, and kyanite, as well as apatite, muscovite, tourmaline, and microscopic primary sillimanite. Potassium feldspar is notably absent. One site, the Thomas Mine, was examined in detail in order to determine the mode of occurrence for these rocks. Excavation revealed pegmatite with two texturally and mineralogically distinct zones. Biotite-rich rocks surrounding the pegmatite indicate strongly potassic alteration of the host hornblendite. Trace element data obtained for kyanite and biotite from the pegmatite show clear patterns related to chemical fractionation of these components during crystallization. Major element geochemistry of the pegmatite and host ,I rocks are consistent with magmatic intrusion. Reaction of the pegmatite melt with the host rocks led to the formation of large amounts of biotite, and depleted the melt in potassium. The remaining melt became saturated in aluminum silicate and crystallized kyanite and sillimanite. Wallrock assemblages, fluid inclusions in pegmatite quartz, the coexistence of kyanite and sillimanite as primary phases, and geothermobarometry on nearby unaltered rocks all indicate conditions of formation of approximately 600-800 MPa and 625-675°C, near those of peak metamorphism for the region."],"dc:description.degree":["Master of Science"],"dc:format.medium":["BTD"],"dc:format.mimetype":["application/pdf"],"dc:identifier.other":["etd-08222008-063115"],"dc:identifier.uri":["http://hdl.handle.net/10919/34704"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["pegmatite","kyanite","magmatic","biotite"],"dc:title":["Petrogenesis and geochemistry of kyanite-bearing pegmatites in the Buncombe Pegmatite District, North Carolina"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Geology"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:19Z"}