This study uses trace elements and radiogenic isotopes (Pb, Sr, and Nd) to investigate the origin and mode of formation for the siliceous deposits in the Lower Mississippian Boone Formation and the Devonian-Mississippian Arkansas Novaculite in the southern midcontinent. Mississippi Valley-type Pb-Zn ore deposits in the Tri-State District and the Northern Arkansas District were deposited by hydrothermal fluids, and highly radiogenic Pb isotope ratios suggest a genetic relationship between the Boone Formation chert (206Pb/204Pb ~ 21.59, 207Pb/204Pb ~ 15.87, 208Pb/204Pb ~ 40.10) and the MVT ores. Due to the very low concentration of Pb in the Boone chert (~2 ppm) and the close proximity of samples containing radiogenic Pb to the tripolitic chert interval, the Boone Formation is interpreted to have been contaminated with radiogenic Pb by the hydrothermal fluids that emplaced the ores. Calculated epsilon values for Nd reveal a small positive shift in the Boone samples (epsilon Nd ~ -5.5) relative to other measured stratigraphic intervals in the southern midcontinent (epsilon Nd ~ -15.2), potentially indicating volcanic contribution of Nd. Upper Boone cherts (epsilon Nd ~ -4.6) and Hatton Tuff (epsilon Nd ~ -3.8) values are remarkably similar, indicating the same Nd source. Sr isotope ratios of the Boone samples (87Sr/86Sr ~ 0.7089) largely reflect Mississippian seawater Sr (87Sr/86Sr ~ 0.7080), while the novaculite samples contain more radiogenic Sr (87Sr/86Sr ~ 0.7121), likely reflecting Sr exchange from the detrital component within the Arkansas Novaculite stratigraphic interval. Rare earth element (REE) concentrations normalized to average continental arcs plot near one for the upper Boone chert samples, indicating similar compositions, while the lower Boone and Arkansas Novaculite have lower normalized values. Rare earth element plus yttrium (REY) concentrations normalized to Post-Archean Australian Shales (PAAS) reveal a negative cerium (Ce) anomaly and a positive yttrium (Y) anomaly, which is a signature of seawater, indicating that the Boone cherts may retain a depositional seawater REY signature.
","abstract_html":"<p>This study uses trace elements and radiogenic isotopes (Pb, Sr, and Nd) to investigate the origin and mode of formation for the siliceous deposits in the Lower Mississippian Boone Formation and the Devonian-Mississippian Arkansas Novaculite in the southern midcontinent. Mississippi Valley-type Pb-Zn ore deposits in the Tri-State District and the Northern Arkansas District were deposited by hydrothermal fluids, and highly radiogenic Pb isotope ratios suggest a genetic relationship between the Boone Formation chert (206Pb/204Pb ~ 21.59, 207Pb/204Pb ~ 15.87, 208Pb/204Pb ~ 40.10) and the MVT ores. Due to the very low concentration of Pb in the Boone chert (~2 ppm) and the close proximity of samples containing radiogenic Pb to the tripolitic chert interval, the Boone Formation is interpreted to have been contaminated with radiogenic Pb by the hydrothermal fluids that emplaced the ores. Calculated epsilon values for Nd reveal a small positive shift in the Boone samples (epsilon Nd ~ -5.5) relative to other measured stratigraphic intervals in the southern midcontinent (epsilon Nd ~ -15.2), potentially indicating volcanic contribution of Nd. Upper Boone cherts (epsilon Nd ~ -4.6) and Hatton Tuff (epsilon Nd ~ -3.8) values are remarkably similar, indicating the same Nd source. Sr isotope ratios of the Boone samples (87Sr/86Sr ~ 0.7089) largely reflect Mississippian seawater Sr (87Sr/86Sr ~ 0.7080), while the novaculite samples contain more radiogenic Sr (87Sr/86Sr ~ 0.7121), likely reflecting Sr exchange from the detrital component within the Arkansas Novaculite stratigraphic interval. Rare earth element (REE) concentrations normalized to average continental arcs plot near one for the upper Boone chert samples, indicating similar compositions, while the lower Boone and Arkansas Novaculite have lower normalized values. Rare earth element plus yttrium (REY) concentrations normalized to Post-Archean Australian Shales (PAAS) reveal a negative cerium (Ce) anomaly and a positive yttrium (Y) anomaly, which is a signature of seawater, indicating that the Boone cherts may retain a depositional seawater REY signature. </p>","abstract_has_math":false,"creators":["Cains, Julie Mary"],"institution":null,"degree_name":"Master of Science in Geology (MS)","degree_level":"Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Potra, Adriana","McGilvery, T.A. \"Mac\""],"advisors":["Manger, Walter L."],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019-05-01T07:00:00Z","date_published":"2019-05-01T07:00:00Z","updated_at":"2026-07-24T00:59:08Z","subjects":["Arkansas","Chert","Novaculite","Radiogenic Isotopes","Trace Elements","Geochemistry","Geology","Geomorphology","Sedimentology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.uark.edu/etd/3248","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Potra, Adriana","McGilvery, T.A. \"Mac\""]},{"key":"dc:contributor.advisor","label":"Advisor","values":["Manger, Walter L."]},{"key":"dc:creator","label":"Author","values":["Cains, Julie Mary"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2019"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2024-02-06T08:00:00Z"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science in Geology (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Arkansas","Chert","Novaculite","Radiogenic Isotopes","Trace Elements","Geochemistry","Geology","Geomorphology","Sedimentology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.uark.edu/etd/3248"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This study uses trace elements and radiogenic isotopes (Pb, Sr, and Nd) to investigate the origin and mode of formation for the siliceous deposits in the Lower Mississippian Boone Formation and the Devonian-Mississippian Arkansas Novaculite in the southern midcontinent. Mississippi Valley-type Pb-Zn ore deposits in the Tri-State District and the Northern Arkansas District were deposited by hydrothermal fluids, and highly radiogenic Pb isotope ratios suggest a genetic relationship between the Boone Formation chert (206Pb/204Pb ~ 21.59, 207Pb/204Pb ~ 15.87, 208Pb/204Pb ~ 40.10) and the MVT ores. Due to the very low concentration of Pb in the Boone chert (~2 ppm) and the close proximity of samples containing radiogenic Pb to the tripolitic chert interval, the Boone Formation is interpreted to have been contaminated with radiogenic Pb by the hydrothermal fluids that emplaced the ores. Calculated epsilon values for Nd reveal a small positive shift in the Boone samples (epsilon Nd ~ -5.5) relative to other measured stratigraphic intervals in the southern midcontinent (epsilon Nd ~ -15.2), potentially indicating volcanic contribution of Nd. Upper Boone cherts (epsilon Nd ~ -4.6) and Hatton Tuff (epsilon Nd ~ -3.8) values are remarkably similar, indicating the same Nd source. Sr isotope ratios of the Boone samples (87Sr/86Sr ~ 0.7089) largely reflect Mississippian seawater Sr (87Sr/86Sr ~ 0.7080), while the novaculite samples contain more radiogenic Sr (87Sr/86Sr ~ 0.7121), likely reflecting Sr exchange from the detrital component within the Arkansas Novaculite stratigraphic interval. Rare earth element (REE) concentrations normalized to average continental arcs plot near one for the upper Boone chert samples, indicating similar compositions, while the lower Boone and Arkansas Novaculite have lower normalized values. Rare earth element plus yttrium (REY) concentrations normalized to Post-Archean Australian Shales (PAAS) reveal a negative cerium (Ce) anomaly and a positive yttrium (Y) anomaly, which is a signature of seawater, indicating that the Boone cherts may retain a depositional seawater REY signature.
"]},{"key":"dc:title","label":"Title","values":["Geochemical Analysis of Mississippian Cherts and Devonian-Mississippian Novaculites, Southern Midcontinent Region"]}]}],"canonical_facts":{"dc:contributor":["Potra, Adriana","McGilvery, T.A. \"Mac\""],"dc:contributor.advisor":["Manger, Walter L."],"dc:creator":["Cains, Julie Mary"],"dc:date":["2019"],"dc:date.available":["2024-02-06T08:00:00Z"],"dc:description.abstract":["This study uses trace elements and radiogenic isotopes (Pb, Sr, and Nd) to investigate the origin and mode of formation for the siliceous deposits in the Lower Mississippian Boone Formation and the Devonian-Mississippian Arkansas Novaculite in the southern midcontinent. Mississippi Valley-type Pb-Zn ore deposits in the Tri-State District and the Northern Arkansas District were deposited by hydrothermal fluids, and highly radiogenic Pb isotope ratios suggest a genetic relationship between the Boone Formation chert (206Pb/204Pb ~ 21.59, 207Pb/204Pb ~ 15.87, 208Pb/204Pb ~ 40.10) and the MVT ores. Due to the very low concentration of Pb in the Boone chert (~2 ppm) and the close proximity of samples containing radiogenic Pb to the tripolitic chert interval, the Boone Formation is interpreted to have been contaminated with radiogenic Pb by the hydrothermal fluids that emplaced the ores. Calculated epsilon values for Nd reveal a small positive shift in the Boone samples (epsilon Nd ~ -5.5) relative to other measured stratigraphic intervals in the southern midcontinent (epsilon Nd ~ -15.2), potentially indicating volcanic contribution of Nd. Upper Boone cherts (epsilon Nd ~ -4.6) and Hatton Tuff (epsilon Nd ~ -3.8) values are remarkably similar, indicating the same Nd source. Sr isotope ratios of the Boone samples (87Sr/86Sr ~ 0.7089) largely reflect Mississippian seawater Sr (87Sr/86Sr ~ 0.7080), while the novaculite samples contain more radiogenic Sr (87Sr/86Sr ~ 0.7121), likely reflecting Sr exchange from the detrital component within the Arkansas Novaculite stratigraphic interval. Rare earth element (REE) concentrations normalized to average continental arcs plot near one for the upper Boone chert samples, indicating similar compositions, while the lower Boone and Arkansas Novaculite have lower normalized values. Rare earth element plus yttrium (REY) concentrations normalized to Post-Archean Australian Shales (PAAS) reveal a negative cerium (Ce) anomaly and a positive yttrium (Y) anomaly, which is a signature of seawater, indicating that the Boone cherts may retain a depositional seawater REY signature.
"],"dc:identifier":["https://scholarworks.uark.edu/etd/3248"],"dc:subject":["Arkansas","Chert","Novaculite","Radiogenic Isotopes","Trace Elements","Geochemistry","Geology","Geomorphology","Sedimentology"],"dc:title":["Geochemical Analysis of Mississippian Cherts and Devonian-Mississippian Novaculites, Southern Midcontinent Region"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science in Geology (MS)"]},"updated_at":"2026-07-24T00:59:08Z"}