Characterization, axial anisotropy and formation conditions of celestine from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southern Libya: Constraints on the mineralogical geothermometer
Аутори
Tančić, PavleMilošević, Maja
Spahić, Darko
Kostić, Bojan
Kremenović, Aleksandar
Poznanović-Spahić, Maja
Kovačević, Jovan
Чланак у часопису (Рецензирана верзија)
Метаподаци
Приказ свих података о документуАпстракт
Five celestine crystals are sampled from the (paleo)surface intervening between the late Miocene to Pleistocene basaltic sequences of the Jabal Eghei(Nuqay) volcanic province (southern Libya). The celestine specimens are characterized by applying the combination of the SEM-WDS, ICP/OES, XRPD, and IR methods. The celestine minerals are further analyzed for their color variations and minerogenetic framework. Three samples have greenish-blue-to-blue (480.4-482.5 nm), whereas the other two samples have blue-green color (cyan; 489.1-494.1 nm). The color purity ranges from 1.36-7.16. Their similarity of chemical content is fitting into the celestine near-end members, in which exclusively 1.6-4.1 at. % of Sr2+ content was substituted by Pb2+ (0.7-0.9 at. %), Ba2+ (0.5-0.7 at. %) and Ca2+ (0.2-0.8 at. %). The composition includes vacancies ranging from 1.0 to 1.9 at. % (observed only in three samples). The content of other chemical elements is minor. The resulting unit-cell parameters have the... following ranges: a0=8.3578(9)-8.3705(6) Å; b0=5.3510(5)-5.3568(4) Å; c0=6.8683(7)-6.8767(2) Å and V0=307.17(5)-308.34(4) Å3. The XRPD and IR results are mainly in accordance with the SEM-WDS results, having a higher level of correlativity. However, the analysis exposed a few discrepancies yielding several possible interpretations. The illustrated discrepancies were primarily caused by a slight unit-cell axial anisotropy i.e., thermal expansion. In this manner, the results yield a new geothermometric tool that is based on the unit-cell axial anisotropy. The investigated Sr-bearing celestines were formed during a Miocene intraplate volcanism, basaltic magmas, and associated brines lifted by the structural conduits (normal faults crosscutting the Sirt basin). The Sr-bearing fluids were then poured into and over the faulted and fractured lagoon-type gypsum, anhydrite Eocene sediments. The celestine minerals were produced within a ~ 368-430K (~ 95-157 oC) temperature range. The celestine is formed at slightly elevated temperature and pressure conditions, close to the shallow subsurface environment (over 250 bars).
Кључне речи:
celestine / characterization / axial anisotropy / formation conditions / Jabal Eghei (Nuqay) volcanic province / southern LibyaИзвор:
Mineralogical Magazine, 2024, 88, 1, 1-18Издавач:
- Cambridge University Press
Финансирање / пројекти:
- Министарство науке, технолошког развоја и иновација Републике Србије, институционално финансирање - 200026 (Универзитет у Београду, Институт за хемију, технологију и металургију - ИХТМ) (RS-MESTD-inst-2020-200026)
Напомена:
- This is accepted version of the manuscript: Tančić, P., Milošević, M., Spahić, D., Kostić, B., Kremenović, A., Poznanović-Spahić, M., & Kovačević, J. (2023). Characterization, axial anisotropy and formation conditions of celestine from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southern Libya: Constraints on the mineralogical geothermometer. Mineralogical Magazine, doi: https://doi.org/10.1180/mgm.2023.88
- Supplementary Materials: https://cer.ihtm.bg.ac.rs/handle/123456789/7147
- Published version: https://cer.ihtm.bg.ac.rs/handle/123456789/7538
- Correction: https://cer.ihtm.bg.ac.rs/handle/123456789/7539
Повезане информације:
- Друга верзија
https://cer.ihtm.bg.ac.rs/handle/123456789/7538 - Повезани садржај
https://cer.ihtm.bg.ac.rs/handle/123456789/7147 - Повезани садржај
https://cer.ihtm.bg.ac.rs/handle/123456789/7539
Институција/група
IHTMTY - JOUR AU - Tančić, Pavle AU - Milošević, Maja AU - Spahić, Darko AU - Kostić, Bojan AU - Kremenović, Aleksandar AU - Poznanović-Spahić, Maja AU - Kovačević, Jovan PY - 2024 UR - https://cer.ihtm.bg.ac.rs/handle/123456789/6913 AB - Five celestine crystals are sampled from the (paleo)surface intervening between the late Miocene to Pleistocene basaltic sequences of the Jabal Eghei(Nuqay) volcanic province (southern Libya). The celestine specimens are characterized by applying the combination of the SEM-WDS, ICP/OES, XRPD, and IR methods. The celestine minerals are further analyzed for their color variations and minerogenetic framework. Three samples have greenish-blue-to-blue (480.4-482.5 nm), whereas the other two samples have blue-green color (cyan; 489.1-494.1 nm). The color purity ranges from 1.36-7.16. Their similarity of chemical content is fitting into the celestine near-end members, in which exclusively 1.6-4.1 at. % of Sr2+ content was substituted by Pb2+ (0.7-0.9 at. %), Ba2+ (0.5-0.7 at. %) and Ca2+ (0.2-0.8 at. %). The composition includes vacancies ranging from 1.0 to 1.9 at. % (observed only in three samples). The content of other chemical elements is minor. The resulting unit-cell parameters have the following ranges: a0=8.3578(9)-8.3705(6) Å; b0=5.3510(5)-5.3568(4) Å; c0=6.8683(7)-6.8767(2) Å and V0=307.17(5)-308.34(4) Å3. The XRPD and IR results are mainly in accordance with the SEM-WDS results, having a higher level of correlativity. However, the analysis exposed a few discrepancies yielding several possible interpretations. The illustrated discrepancies were primarily caused by a slight unit-cell axial anisotropy i.e., thermal expansion. In this manner, the results yield a new geothermometric tool that is based on the unit-cell axial anisotropy. The investigated Sr-bearing celestines were formed during a Miocene intraplate volcanism, basaltic magmas, and associated brines lifted by the structural conduits (normal faults crosscutting the Sirt basin). The Sr-bearing fluids were then poured into and over the faulted and fractured lagoon-type gypsum, anhydrite Eocene sediments. The celestine minerals were produced within a ~ 368-430K (~ 95-157 oC) temperature range. The celestine is formed at slightly elevated temperature and pressure conditions, close to the shallow subsurface environment (over 250 bars). PB - Cambridge University Press T2 - Mineralogical Magazine T1 - Characterization, axial anisotropy and formation conditions of celestine from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southern Libya: Constraints on the mineralogical geothermometer VL - 88 IS - 1 SP - 1 EP - 18 DO - 10.1180/mgm.2023.88 ER -
@article{ author = "Tančić, Pavle and Milošević, Maja and Spahić, Darko and Kostić, Bojan and Kremenović, Aleksandar and Poznanović-Spahić, Maja and Kovačević, Jovan", year = "2024", abstract = "Five celestine crystals are sampled from the (paleo)surface intervening between the late Miocene to Pleistocene basaltic sequences of the Jabal Eghei(Nuqay) volcanic province (southern Libya). The celestine specimens are characterized by applying the combination of the SEM-WDS, ICP/OES, XRPD, and IR methods. The celestine minerals are further analyzed for their color variations and minerogenetic framework. Three samples have greenish-blue-to-blue (480.4-482.5 nm), whereas the other two samples have blue-green color (cyan; 489.1-494.1 nm). The color purity ranges from 1.36-7.16. Their similarity of chemical content is fitting into the celestine near-end members, in which exclusively 1.6-4.1 at. % of Sr2+ content was substituted by Pb2+ (0.7-0.9 at. %), Ba2+ (0.5-0.7 at. %) and Ca2+ (0.2-0.8 at. %). The composition includes vacancies ranging from 1.0 to 1.9 at. % (observed only in three samples). The content of other chemical elements is minor. The resulting unit-cell parameters have the following ranges: a0=8.3578(9)-8.3705(6) Å; b0=5.3510(5)-5.3568(4) Å; c0=6.8683(7)-6.8767(2) Å and V0=307.17(5)-308.34(4) Å3. The XRPD and IR results are mainly in accordance with the SEM-WDS results, having a higher level of correlativity. However, the analysis exposed a few discrepancies yielding several possible interpretations. The illustrated discrepancies were primarily caused by a slight unit-cell axial anisotropy i.e., thermal expansion. In this manner, the results yield a new geothermometric tool that is based on the unit-cell axial anisotropy. The investigated Sr-bearing celestines were formed during a Miocene intraplate volcanism, basaltic magmas, and associated brines lifted by the structural conduits (normal faults crosscutting the Sirt basin). The Sr-bearing fluids were then poured into and over the faulted and fractured lagoon-type gypsum, anhydrite Eocene sediments. The celestine minerals were produced within a ~ 368-430K (~ 95-157 oC) temperature range. The celestine is formed at slightly elevated temperature and pressure conditions, close to the shallow subsurface environment (over 250 bars).", publisher = "Cambridge University Press", journal = "Mineralogical Magazine", title = "Characterization, axial anisotropy and formation conditions of celestine from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southern Libya: Constraints on the mineralogical geothermometer", volume = "88", number = "1", pages = "1-18", doi = "10.1180/mgm.2023.88" }
Tančić, P., Milošević, M., Spahić, D., Kostić, B., Kremenović, A., Poznanović-Spahić, M.,& Kovačević, J.. (2024). Characterization, axial anisotropy and formation conditions of celestine from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southern Libya: Constraints on the mineralogical geothermometer. in Mineralogical Magazine Cambridge University Press., 88(1), 1-18. https://doi.org/10.1180/mgm.2023.88
Tančić P, Milošević M, Spahić D, Kostić B, Kremenović A, Poznanović-Spahić M, Kovačević J. Characterization, axial anisotropy and formation conditions of celestine from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southern Libya: Constraints on the mineralogical geothermometer. in Mineralogical Magazine. 2024;88(1):1-18. doi:10.1180/mgm.2023.88 .
Tančić, Pavle, Milošević, Maja, Spahić, Darko, Kostić, Bojan, Kremenović, Aleksandar, Poznanović-Spahić, Maja, Kovačević, Jovan, "Characterization, axial anisotropy and formation conditions of celestine from the Jabal Eghei (Nuqay) late Neogene – Pleistocene volcanic province, southern Libya: Constraints on the mineralogical geothermometer" in Mineralogical Magazine, 88, no. 1 (2024):1-18, https://doi.org/10.1180/mgm.2023.88 . .