Single-zircon Pb-evaporation and 40Ar/39Ar dating of the metamorphic and granitic rocks in north-west Spitsbergen

Ohta, Y.; Ларионов, А. Н.; Tebenkov, Alexander M.; Lepvrier, Claude; Maluski, H.; Lange, Michael; Hellebrandt, Barbara

doi:10.3402/polar.v21i1.6475

Cited by 14 publications

(20 citation statements)

References 32 publications

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“…A notably high proportion of dated zircon grains are in this age range, similar to the same characteristics of the NBH and north-western Spitsbergen gneissose migmatites ( Fig 6) (Balašov et al 1996b;Ohta et al 2002). Granitoids in the western half of Ny-Friesland, ca.…”

Section: Latest Palaeoproterozoic and Older Agessupporting

confidence: 70%

“…6a) is generally similar to that of the north-western Spitsbergen (Fig. 6b) (Ohta 1992;Balašov et al 1996b;Ohta et al 2002), but markedly different from the western half of Ny-Friesland, which comprise latest Palaeoproterozoic granitoids and lack Grenvillian rocks.…”

Section: Discussionmentioning

confidence: 62%

“…4). A massive homogeneous, leucocratic granite, similar to the grey granite of north-western Spitsbergen (Balašov et al 1996b;Ohta et al 2002), cuts all other metamorphic and migmatitic rocks.…”

Section: Granitic Neosome Of Migmatite From the West Of Bockfjorden Sbhmentioning

confidence: 97%

“…This suggests lithological correlation. Single-zircon Pb evaporation dating studies of the rocks in the north-western basement rocks have recently been presented by Balašov et al (1996b) and Ohta et al (2002). The present article reports the dating results by the single-zircon Pb evaporation method on the rocks of the BHZ.…”

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confidence: 88%

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Single-grain zircon dating of the metamorphic and granitic rocks from the Biscayarhalv�ya-Holtedahlfonna zone, north-west Spitsbergen

Ohta

Ларионов

Tebenkov³

2003

Polar Research

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The Biscayarhalvøya‐Holtedahlfonna zone (BHZ) in north‐western Spitsbergen is a north‐south trending, narrow horst, with crystalline basement rocks exposed under a Devonian unconformity. Previous K‐Ar, 40Ar/39Ar and Rb‐Sr analyses have confirmed the occurrence of Caledonian thermal events, and Grenvillian ages have been obtained by conventional zircon U‐Pb and single‐zircon Pb evaporation methods. A total of 55 zircon grains from three samples (an augen metagranite, a micaceous schist and a granitic neosome of migmatite) have been analysed by the single‐zircon Pb evaporation method. The grains with the age range of ca. 950‐1100 My (million years) are the major component in all three samples, suggesting tectono‐thermal activity in that period. The detrital versus resorption orgin of the rounded shapes of these grains from the granitic neosome is not clear yet. Therefore, the ages of the migmatization and of the sedimentary protoliths are not concluded. The youngest presumed detrital grain from the granitic neosome is 1060 My old. The metagranite, cutting the Richarddalen unit, yielded grains with an age of ca. 950 Mya. A granite dyke with an age range of 955‐968 My cuts the Biscayarhuken unit in the northern Liefdefjorden area. These indicate the sedimentary protoliths of the Richarddalen and Biscayarhuken units are pre‐Neoproterozoic. The youngest detrital zircon ages of ca. 940 My indicate Neoproterozoic sedimentary protoliths of the Solanderfjellet micaceous schists. A significant population of zircon grains with an age range of 1600‐1900 My in all three samples suggests a wide exposure of these rocks in the source areas during Meso‐ and Neoproterozoic times. Several Archean ages have also been obtained. The results are generally conformable with those obtained from north‐western Spitsbergen.

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Section: Latest Palaeoproterozoic and Older Agessupporting

confidence: 70%

Section: Discussionmentioning

confidence: 62%

Section: Granitic Neosome Of Migmatite From the West Of Bockfjorden Sbhmentioning

confidence: 97%

mentioning

confidence: 88%

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Single-grain zircon dating of the metamorphic and granitic rocks from the Biscayarhalv�ya-Holtedahlfonna zone, north-west Spitsbergen

Ohta

Ларионов

Tebenkov³

2003

Polar Research

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mentioning

confidence: 88%

Single-grain zircon dating of the metamorphic and granitic rocks from the Biscayarhalvøya-Holtedahlfonna zone, north-west Spitsbergen

Ohta

Ларионов

Tebenkov³

2003

Polar Research

Self Cite

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The Biscayarhalvøya-Holtedahlfonna zone (BHZ) in north-western Spitsbergen is a north-south trending, narrow horst, with crystalline basement rocks exposed under a Devonian unconformity. Previous K-Ar, 40 Ar/ 39 Ar and Rb-Sr analyses have confi rmed the occurrence of Caledonian thermal events, and Grenvillian ages have been obtained by conventional zircon U-Pb and single-zircon Pb evaporation methods. A total of 55 zircon grains from three samples (an augen metagranite, a micaceous schist and a granitic neosome of migmatite) have been analysed by the single-zircon Pb evaporation method. The grains with the age range of ca. 950 -1100 My (million years) are the major component in all three samples, suggesting tectono-thermal activity in that period. The detrital versus resorption orgin of the rounded shapes of these grains from the granitic neosome is not clear yet. Therefore, the ages of the migmatization and of the sedimentary protoliths are not concluded. The youngest presumed detrital grain from the granitic neosome is 1060 My old. The metagranite, cutting the Richarddalen unit, yielded grains with an age of ca. 950 Mya. A granite dyke with an age range of 955 -968 My cuts the Biscayarhuken unit in the northern Liefdefjorden area. These indicate the sedimentary protoliths of the Richarddalen and Biscayarhuken units are pre-Neoproterozoic. The youngest detrital zircon ages of ca. 940 My indicate Neoproterozoic sedimentary protoliths of the Solanderfjellet micaceous schists. A signifi cant population of zircon grains with an age range of 1600 -1900 My in all three samples suggests a wide exposure of these rocks in the source areas during Meso-and Neoproterozoic times. Several Archean ages have also been obtained. The results are generally conformable with those obtained from north-western Spitsbergen.

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Magmatic and metamorphic events recorded within the Southwestern Basement Province of Svalbard

Majka

Kośmińska

2017

Arktos

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A recent increase in fieldwork activity within the Southwestern Basement Province (SBP) of Svalbard followed by detailed geochronological and petrological studies has allowed recognition of previously unknown magmatic and metamorphic events in the studied region. These discoveries of, e.g. true c. 950 Ma granitic magmatism, c. 640 Ma Torellian metamorphism, completely new localities of high-pressure rocks and a c. 360 Ma Ellesmerian, Barrovian-type metamorphic sequence emphasize the importance of further research in this part of the Svalbard Archipelago. Paleogene tectonic overprint of the SBP, manifested by the West Spitsbergen Fold and Thrust Belt, is an additional challenge for geologists working in this part of Svalbard's crystalline basement, and must be taken into account in all interpretations of pre-Cenozoic structures. Several enigmatic issues concerning the evolution of the SBP remain unanswered. Hence, there is a need for continued research in this key area for understanding the geological evolution of the northern Barents Shelf and High Arctic in general.

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Single-zircon Pb-evaporation and 40Ar/39Ar dating of the metamorphic and granitic rocks in north-west Spitsbergen

Cited by 14 publications

References 32 publications

Single-grain zircon dating of the metamorphic and granitic rocks from the Biscayarhalv�ya-Holtedahlfonna zone, north-west Spitsbergen

Single-grain zircon dating of the metamorphic and granitic rocks from the Biscayarhalv�ya-Holtedahlfonna zone, north-west Spitsbergen

Single-grain zircon dating of the metamorphic and granitic rocks from the Biscayarhalvøya-Holtedahlfonna zone, north-west Spitsbergen

Magmatic and metamorphic events recorded within the Southwestern Basement Province of Svalbard

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