Age dating of individual grains of uraninite in rocks from electron microprobe analyses

Bowles, John F. W.

doi:10.1016/0009-2541(90)90139-x

Cited by 137 publications

(67 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Dating of uraninite shows an average age of 14.2± 0.2 Ma (9 measurements). Similar average ages have been obtained from alternative methods of uraninite age calculations, namely 14.5± 0.3 Ma of Ranchin (1968), 12.5± 0.5 Ma of CameronSchiman (1978), and 13.9±0.3 Ma of Bowles (1990).…”

Section: Chemical Dating Of Monazite and Uraninitesupporting

confidence: 75%

“…Spot analyses of monazite and uraninite were corrected for mutual interferences and then the weighted average of apparent ages were calculated following the statistical method of Montel et al (1996). Moreover, an average age of uraninite was also calculated by the alternative methods of Ranchin (1968), Cameron-Schiman (1978) and Bowles (1990). …”

Section: Methodsmentioning

confidence: 99%

“…Dating of monazite and uraninite based on high Th and/or U content, together with measurable amounts of Pb and negligible content of common, non-radiogenic lead (Bowles 1990;Montel et al 1996, and references therein) has been applied to determine the age of the Visole pegmatite. Concentrations of U, Th and Pb in monazite and uraninite were measured using the electron microprobe as described above, and the age was calculated according to the Montel et al (1996) and Konečný et al (2004) procedure.…”

Section: Chemical Dating Of Monazite and Uraninitementioning

confidence: 99%

See 2 more Smart Citations

Rare-element granitic pegmatite of Miocene age emplaced in UHP rocks from Visole, Pohorje Mountains (Eastern Alps, Slovenia): accessory minerals, monazite and uraninite chemical dating

Uher¹,

Janák²,

Konečný³

et al. 2014

Geologica Carpathica

View full text Add to dashboard Cite

Abstract:The granitic pegmatite dike intruded the Cretaceous UHP rocks at Visole, near Slovenska Bistrica, in the Pohorje Mountains (Slovenia). The rock consists mainly of K-feldspar, albite and quartz, subordinate muscovite and biotite, while the accessory minerals include spessartine-almandine, zircon, ferrocolumbite, fluorapatite, monazite-(Ce), uraninite, and magnetite. Compositions of garnet (Sps [48][49] Alm [45][46] Grs +And 3-4 Prp 1.5-2 ), metamict zircon with 3.5 to 7.8 wt. % HfO 2 [atom. 100Hf/(Hf + Zr) = 3.3-7.7] and ferrocolumbite [atom. Mn/(Mn + Fe) = 0.27-0.43, Ta/(Ta + Nb) = 0.03-0.46] indicate a relatively low to medium degree of magmatic fractionation, characteristic of the muscovite -rare-element class or beryl-columbite subtype of the rare-element class pegmatites. Monazite-(Ce) reveals elevated Th and U contents ( ≤ 11 wt. % ThO 2 , ≤ 5 wt. % UO 2 ). The monazite-garnet geothermometer shows a possible precipitation temperature of ~495 ± 30 °C at P~4 to 5 kbar. Chemical U-Th-Pb dating of the monazite yielded a Miocene age (17.2 ± 1.8 Ma), whereas uraninite gave a younger (~14 Ma) age. These ages are comtemporaneous with the main crystallization and emplacement of the Pohorje pluton and adjacent volcanic rocks (20 to 15 Ma), providing the first documented evidence of Neogene granitic pegmatites in the Eastern Alps. Consequently, the Visole pegmatite belongs to the youngest rare-element granitic pegmatite populations in Europe, together with the Paleogene pegmatite occurrences along the Periadriatic (Insubric) Fault System in the Alps and in the Rhodope Massif, as well as the Late Miocene to Pliocene pegmatites in the Tuscany magmatic province (mainly on the Island of Elba).

show abstract

Section: Chemical Dating Of Monazite and Uraninitesupporting

confidence: 75%

Section: Methodsmentioning

confidence: 99%

Section: Chemical Dating Of Monazite and Uraninitementioning

confidence: 99%

See 1 more Smart Citation

Rare-element granitic pegmatite of Miocene age emplaced in UHP rocks from Visole, Pohorje Mountains (Eastern Alps, Slovenia): accessory minerals, monazite and uraninite chemical dating

Uher¹,

Janák²,

Konečný³

et al. 2014

Geologica Carpathica

View full text Add to dashboard Cite

show abstract

“…Assuming that all Pb in thorianite are radiogenic and partial lead -loss did not occur (e.g., Bowles, 1990), the total U -Th -Pb age of thorianite can be determined. We mainly follow the theoretical basis of electron microprobe dating shown in publications (e.g., Bowles, 1990;Suzuki and Adachi, 1991), but we do not follow the algorithm in p. 49 of Bowles (1990) who searched a root at a 1 Ma step.…”

Section: Mineral Compositions Of the Ms Inclusion And Thorianite Agementioning

confidence: 99%

“…We mainly follow the theoretical basis of electron microprobe dating shown in publications (e.g., Bowles, 1990;Suzuki and Adachi, 1991), but we do not follow the algorithm in p. 49 of Bowles (1990) who searched a root at a 1 Ma step. We have determined the root by the Newton -Raphson method.…”

Section: Mineral Compositions Of the Ms Inclusion And Thorianite Agementioning

confidence: 99%

Age determination of thorianite in phlogopite-bearing spinel-garnet peridotite in the Gföhl Unit, Moldanubian Zone of the Bohemian Massif

Naemura

YOKOYAMA

Hirajima

et al. 2008

Journal of Mineralogical and Petrological Sciences

View full text Add to dashboard Cite

Thorianite (ThO 2 ) was found in the phlogopite -bearing spinel -garnet peridotite (Plešovice peridotite) occurring as decimeter -size lenticular body in the Gföhl granulite that forms the metamorphic core of the Variscan orogenic belt. Thorianite occurs as a member of multiphase solid inclusions, consisting of phlogopite + carbonates + apatite + graphite + rutile + monazite + thorianite, in chromian spinel. U -Th -Pb ages of the thorianite give a good concentration at 333.8 ± 4.5 Ma, which overlaps the U -Pb ages of zircon extracted from the host Gföhl granulite, probably reflecting the Variscan high -pressure high -temperature metamorphism during the continentcontinent collision.

show abstract

Hydrocarbon migration in the Solway Basin

Parnell¹

1995

Geological Journal

View full text Add to dashboard Cite

Carboniferous rocks in the north Solway onshore outcrop show evidence of hydrocarbon migration. Oil residues occur as intergranular bitumen in sandstones, thoriferous bitumen nodules in sandstones and uraniferous bitumens in fractures associated with the North Solway Fault at the northern margin of the Solway Basin. Oil was emplaced in sandstones after the dissolution of dolomite, calcite and clay cements. The radioelement-rich bitumens represent deposition following interactions between migrating hydrocarbons and metalliferous fluids. The close proximity of the Caledonian Criffel granodiorite, unroofed by Carboniferous times, suggests that the pluton was the source of uranium and thorium. Hydrocarbon source rocks are identified further east in the more complete succession exposed in the Esk Valley region, along with further oil residues. Time-temperature modelling suggests that oil was generated from Lower Carboniferous source rocks during the Permo-Triassic. Chemical age dating of uraninite in bitumen yields early Jurassic ages, which may reflect the time of hydrocarbon migration along the North Solway Fault system, and may be related to a mid-Jurassic episode of regional uplift. Analyses of thorite in bitumen nodules give a wider spread of data, probably due to the migration of daughter lead.

show abstract

Age dating of individual grains of uraninite in rocks from electron microprobe analyses

Cited by 137 publications

References 10 publications

Rare-element granitic pegmatite of Miocene age emplaced in UHP rocks from Visole, Pohorje Mountains (Eastern Alps, Slovenia): accessory minerals, monazite and uraninite chemical dating

Rare-element granitic pegmatite of Miocene age emplaced in UHP rocks from Visole, Pohorje Mountains (Eastern Alps, Slovenia): accessory minerals, monazite and uraninite chemical dating

Age determination of thorianite in phlogopite-bearing spinel-garnet peridotite in the Gföhl Unit, Moldanubian Zone of the Bohemian Massif

Hydrocarbon migration in the Solway Basin

Contact Info

Product

Resources

About