Article
Licensed
Unlicensed
Requires Authentication
Geochemistry of pyrochlore minerals from the Motzfeldt Center, South Greenland: The mineralogy of a syenite-hosted Ta, Nb deposit
-
Jamie A. McCreath
,
Donald A. Herd
Published/Copyright:
March 7, 2015
Abstract
Pyrochlore minerals are common accessory phases in the syenite and nepheline syenite rocks of the Motzfeldt alkaline center, Gardar Province, South Greenland, and are of important economic interest due to their exceptional ability to host various high field strength elements. In this study pyrochlore from two distinct intrusive units within the Motzfeldt Center have been studied. The largely homogeneous syenite and nepheline syenite rocks of the Flinks Dal formation host oscillatory and sector-zoned pyrochlore, which have experienced minor alteration in the presence of high-temperature, dominantly juvenile magmatic fluids. Alteration is characterized by variable decrease in the Na, Ca, and F contents and addition of Sr and K, accompanied by introduction of A and Y site vacancies. Pyrochlore from the more heterogeneous and intensely altered syenite rocks of the Motzfeldt Sø Formation are pervasively altered through interaction with lower temperature evolved hydrothermal fluids. During this phase of alteration cations are preferentially leached from the A and Y sites, accompanied by progressively increasing hydration. In both formations the proportion of B-site cations remains unaltered regardless of the degree of alteration. The alteration encoded in the pyrochlores of the Motzfeldt Center records the different hydrothermal conditions the two formations experienced during the subsolidus, showing how evolution of fluids within one intrusive unit can vary both spatially and temporally.
Keywords : Gardar province; alkaline rocks; high field strength elements; tantalum; hydrothermal alteration
Received: 2011-11-24
Accepted: 2012-10-10
Published Online: 2015-3-7
Published in Print: 2013-2-1
© 2015 by Walter de Gruyter Berlin/Boston
You are currently not able to access this content.
You are currently not able to access this content.
Articles in the same Issue
- Pressure-induced structural transformations in the low-cristobalite form of AlPO4
- Hydrokenomicrolite, (□,H2O)2Ta2(O,OH)6(H2O), a new microlite-group mineral from Volta Grande pegmatite, Nazareno, Minas Gerais, Brazil
- Fluor-elbaite, Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3F, a new mineral species of the tourmaline supergroup
- Microtexture development during rapid cooling in three rhyolitic lava flows
- Microbial and inorganic control on the composition of clay from volcanic glass alteration experiments
- High-pressure experiments on phase transition boundaries between corundum, Rh2O3(II)- and CaIrO3-type structures in Al2O3
- Electronic structure effects in the vectorial bond-valence model
- Geometric analysis of radiation damage connectivity in zircon, and its implications for helium diffusion
- Superstructure, crystal chemistry, and cation distribution in filipstadite, a Sb5+-bearing, spinel-related mineral
- A high-temperature Brillouin scattering study on four compositions of haplogranitic glasses and melts: High-frequency elastic behavior through the glass transition
- Hydrogen isotope fractionation between coexisting hydrous melt and silicate-saturated aqueous fluid: An experimental study in situ at high pressure and temperature
- Eclogitic clasts with omphacite and pyrope-rich garnet in the NWA 801 CR2 chondrite
- Hydration properties of synthetic high-charge micas saturated with different cations: An experimental approach
- Quantitative analyses of powdered multi-minerallic carbonate aggregates using a portable Raman spectrometer
- Periodic ab initio bulk investigation of hydroxylapatite and type A carbonated apatite with both pseudopotential and all-electron basis sets for calcium atoms
- Coexisting pseudobrookite, ilmenite, and titanomagnetite in hornblende andesite of the Coleman Pinnacle flow, Mount Baker, Washington: Evidence for a highly oxidized arc magma
- Geochemistry of pyrochlore minerals from the Motzfeldt Center, South Greenland: The mineralogy of a syenite-hosted Ta, Nb deposit
- Phosphovanadylite-Ca, Ca[V4 4+P2O8(OH)8]·12H2O, the Ca analogue of phosphovanadylite-Ba
- The relationship between REE-Y-Nb-Th minerals and the evolution of an A-type granite, Wentworth Pluton, Nova Scotia
- Prewittite, KPb1.5Cu6Zn(SeO3)2O2Cl10, a new mineral from Tolbachik fumaroles, Kamchatka peninsula, Russia: Description and crystal structure
- Lucabindiite, (K,NH4)As4O6(Cl,Br), a new fumarole mineral from the “La Fossa” crater at Vulcano, Aeolian Islands, Italy
- Scottyite, the natural analog of synthetic BaCu2Si2O7, a new mineral from the Wessels mine, Kalahari Manganese Fields, South Africa
- Oxy-schorl, Na(Fe2 2+Al)Al6Si6O18(BO3)3(OH)3O, a new mineral from Zlatá Idka, Slovak Republic and Přibyslavice, Czech Republic
- Crystal chemistry and hydrogen bonding of rustumite Ca10(Si2O7)2(SiO4)(OH)2Cl2 with variable OH, Cl, F
- Oxy-vanadium-dravite, NaV3(V4Mg2)(Si6O18)(BO3)3(OH)3O: Crystal structure and redefinition of the “vanadium-dravite” tourmaline
- Lead-tellurium oxysalts from Otto Mountain near Baker, California: VIII. Fuettererite, Pb3Cu2+ 6 Te6+O6(OH)7Cl5, a new mineral with double spangolite-type sheets
- Lead-tellurium oxysalts from Otto Mountain near Baker, California: IX. Agaite, Pb3Cu2+Te6+O5(OH)2(CO3), a new mineral with CuO5-TeO6 polyhedral sheets
- Letter: Actinides in Geology, Energy, and the Environment. Evidence for nanocrystals of vorlanite, a rare uranate mineral, in the Nopal I low-temperature uranium deposit (Sierra Peña Blanca, Mexico)
Keywords for this article
Gardar province;
alkaline rocks;
high field strength elements;
tantalum;
hydrothermal alteration
Articles in the same Issue
- Pressure-induced structural transformations in the low-cristobalite form of AlPO4
- Hydrokenomicrolite, (□,H2O)2Ta2(O,OH)6(H2O), a new microlite-group mineral from Volta Grande pegmatite, Nazareno, Minas Gerais, Brazil
- Fluor-elbaite, Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3F, a new mineral species of the tourmaline supergroup
- Microtexture development during rapid cooling in three rhyolitic lava flows
- Microbial and inorganic control on the composition of clay from volcanic glass alteration experiments
- High-pressure experiments on phase transition boundaries between corundum, Rh2O3(II)- and CaIrO3-type structures in Al2O3
- Electronic structure effects in the vectorial bond-valence model
- Geometric analysis of radiation damage connectivity in zircon, and its implications for helium diffusion
- Superstructure, crystal chemistry, and cation distribution in filipstadite, a Sb5+-bearing, spinel-related mineral
- A high-temperature Brillouin scattering study on four compositions of haplogranitic glasses and melts: High-frequency elastic behavior through the glass transition
- Hydrogen isotope fractionation between coexisting hydrous melt and silicate-saturated aqueous fluid: An experimental study in situ at high pressure and temperature
- Eclogitic clasts with omphacite and pyrope-rich garnet in the NWA 801 CR2 chondrite
- Hydration properties of synthetic high-charge micas saturated with different cations: An experimental approach
- Quantitative analyses of powdered multi-minerallic carbonate aggregates using a portable Raman spectrometer
- Periodic ab initio bulk investigation of hydroxylapatite and type A carbonated apatite with both pseudopotential and all-electron basis sets for calcium atoms
- Coexisting pseudobrookite, ilmenite, and titanomagnetite in hornblende andesite of the Coleman Pinnacle flow, Mount Baker, Washington: Evidence for a highly oxidized arc magma
- Geochemistry of pyrochlore minerals from the Motzfeldt Center, South Greenland: The mineralogy of a syenite-hosted Ta, Nb deposit
- Phosphovanadylite-Ca, Ca[V4 4+P2O8(OH)8]·12H2O, the Ca analogue of phosphovanadylite-Ba
- The relationship between REE-Y-Nb-Th minerals and the evolution of an A-type granite, Wentworth Pluton, Nova Scotia
- Prewittite, KPb1.5Cu6Zn(SeO3)2O2Cl10, a new mineral from Tolbachik fumaroles, Kamchatka peninsula, Russia: Description and crystal structure
- Lucabindiite, (K,NH4)As4O6(Cl,Br), a new fumarole mineral from the “La Fossa” crater at Vulcano, Aeolian Islands, Italy
- Scottyite, the natural analog of synthetic BaCu2Si2O7, a new mineral from the Wessels mine, Kalahari Manganese Fields, South Africa
- Oxy-schorl, Na(Fe2 2+Al)Al6Si6O18(BO3)3(OH)3O, a new mineral from Zlatá Idka, Slovak Republic and Přibyslavice, Czech Republic
- Crystal chemistry and hydrogen bonding of rustumite Ca10(Si2O7)2(SiO4)(OH)2Cl2 with variable OH, Cl, F
- Oxy-vanadium-dravite, NaV3(V4Mg2)(Si6O18)(BO3)3(OH)3O: Crystal structure and redefinition of the “vanadium-dravite” tourmaline
- Lead-tellurium oxysalts from Otto Mountain near Baker, California: VIII. Fuettererite, Pb3Cu2+ 6 Te6+O6(OH)7Cl5, a new mineral with double spangolite-type sheets
- Lead-tellurium oxysalts from Otto Mountain near Baker, California: IX. Agaite, Pb3Cu2+Te6+O5(OH)2(CO3), a new mineral with CuO5-TeO6 polyhedral sheets
- Letter: Actinides in Geology, Energy, and the Environment. Evidence for nanocrystals of vorlanite, a rare uranate mineral, in the Nopal I low-temperature uranium deposit (Sierra Peña Blanca, Mexico)
