Thrich loparite from the Khibina alkaline complex, Kola Peninsula: isomorphism and paragenesis
Th-rich (up to 18.4 wt. % ThO2) loparite occurs as an accessory phase in foyaite pegmatites at Mt. Eveslogchorr, Khibina complex, Russia. It is associated with aegirine, astrophyllite, eudialyte, lorenzenite, lamprophyllite, magnesio-arfvedsonite and gerasimovskite. Loparite crystals are zoned from...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.578.3019 2023-05-15T17:04:54+02:00 Thrich loparite from the Khibina alkaline complex, Kola Peninsula: isomorphism and paragenesis Roger H. Mitchell Anton R. Chakhmouradian The Pennsylvania State University CiteSeerX Archives 1998 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.578.3019 http://rruff.info/doclib/mm/vol62/MM62_341.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.578.3019 http://rruff.info/doclib/mm/vol62/MM62_341.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://rruff.info/doclib/mm/vol62/MM62_341.pdf loparite betafite belyankinite nepheline-syenite pegmatite Khibina alkaline complex Kola Peninsula Russia text 1998 ftciteseerx 2016-01-08T12:51:22Z Th-rich (up to 18.4 wt. % ThO2) loparite occurs as an accessory phase in foyaite pegmatites at Mt. Eveslogchorr, Khibina complex, Russia. It is associated with aegirine, astrophyllite, eudialyte, lorenzenite, lamprophyllite, magnesio-arfvedsonite and gerasimovskite. Loparite crystals are zoned from niobian loparite (core) to niobian thorian and thorian niobian loparite (rim). Th-enrichment is accompanied by a decrease in Na, LREE, Sr and increase in A-site vacancies. The most Th-rich composition approaches (Na0.39LREE0.19Th0.12Ca0.05Sr0.02)S0.77(Ti0.76Nb0.27)S1.03O3. The mineral is partly or completely metamict and after annealing gives an X-ray diffraction powder pattern similar to that of synthetic NaLaTi2O6 and naturally occurring loparite of different composition. For the Th-rich rim sample, the five strongest diffraction lines (AÊ) are: 2.72 (100) 110, 1.575 (60) 211, 1.925 (40), 1.368 (30) 220, 1.222 (20) 310; a = 3.867(2) AÊ. The X-ray diffraction patterns do not exhibit peak splitting or other diffraction lines typical of low-symmetry and ordered perovskite-type structures. Composition determinations, infrared transmission spectroscopy and X-ray diffractometry show that thorian loparite is partly replaced by betafite with LREE and Th as dominant A-site cations (‘ceriobetafite’). Some loparite samples also exhibit thin replacement mantles of belyankinite with high LREE2O3 and ThO2 contents. Both ‘ceriobetafite ’ and belyankinite were formed due to metasomatic alteration of loparite. Text kola peninsula Unknown Kola Peninsula |
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Open Polar |
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Unknown |
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ftciteseerx |
language |
English |
topic |
loparite betafite belyankinite nepheline-syenite pegmatite Khibina alkaline complex Kola Peninsula Russia |
spellingShingle |
loparite betafite belyankinite nepheline-syenite pegmatite Khibina alkaline complex Kola Peninsula Russia Roger H. Mitchell Anton R. Chakhmouradian Thrich loparite from the Khibina alkaline complex, Kola Peninsula: isomorphism and paragenesis |
topic_facet |
loparite betafite belyankinite nepheline-syenite pegmatite Khibina alkaline complex Kola Peninsula Russia |
description |
Th-rich (up to 18.4 wt. % ThO2) loparite occurs as an accessory phase in foyaite pegmatites at Mt. Eveslogchorr, Khibina complex, Russia. It is associated with aegirine, astrophyllite, eudialyte, lorenzenite, lamprophyllite, magnesio-arfvedsonite and gerasimovskite. Loparite crystals are zoned from niobian loparite (core) to niobian thorian and thorian niobian loparite (rim). Th-enrichment is accompanied by a decrease in Na, LREE, Sr and increase in A-site vacancies. The most Th-rich composition approaches (Na0.39LREE0.19Th0.12Ca0.05Sr0.02)S0.77(Ti0.76Nb0.27)S1.03O3. The mineral is partly or completely metamict and after annealing gives an X-ray diffraction powder pattern similar to that of synthetic NaLaTi2O6 and naturally occurring loparite of different composition. For the Th-rich rim sample, the five strongest diffraction lines (AÊ) are: 2.72 (100) 110, 1.575 (60) 211, 1.925 (40), 1.368 (30) 220, 1.222 (20) 310; a = 3.867(2) AÊ. The X-ray diffraction patterns do not exhibit peak splitting or other diffraction lines typical of low-symmetry and ordered perovskite-type structures. Composition determinations, infrared transmission spectroscopy and X-ray diffractometry show that thorian loparite is partly replaced by betafite with LREE and Th as dominant A-site cations (‘ceriobetafite’). Some loparite samples also exhibit thin replacement mantles of belyankinite with high LREE2O3 and ThO2 contents. Both ‘ceriobetafite ’ and belyankinite were formed due to metasomatic alteration of loparite. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Roger H. Mitchell Anton R. Chakhmouradian |
author_facet |
Roger H. Mitchell Anton R. Chakhmouradian |
author_sort |
Roger H. Mitchell |
title |
Thrich loparite from the Khibina alkaline complex, Kola Peninsula: isomorphism and paragenesis |
title_short |
Thrich loparite from the Khibina alkaline complex, Kola Peninsula: isomorphism and paragenesis |
title_full |
Thrich loparite from the Khibina alkaline complex, Kola Peninsula: isomorphism and paragenesis |
title_fullStr |
Thrich loparite from the Khibina alkaline complex, Kola Peninsula: isomorphism and paragenesis |
title_full_unstemmed |
Thrich loparite from the Khibina alkaline complex, Kola Peninsula: isomorphism and paragenesis |
title_sort |
thrich loparite from the khibina alkaline complex, kola peninsula: isomorphism and paragenesis |
publishDate |
1998 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.578.3019 http://rruff.info/doclib/mm/vol62/MM62_341.pdf |
geographic |
Kola Peninsula |
geographic_facet |
Kola Peninsula |
genre |
kola peninsula |
genre_facet |
kola peninsula |
op_source |
http://rruff.info/doclib/mm/vol62/MM62_341.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.578.3019 http://rruff.info/doclib/mm/vol62/MM62_341.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766059265338900480 |