The age of camptonite dikes of the Agardag alkali-basalt complex (western Sangilen): Results of Ar/Ar and U/Pb dating

A. A. Gibsher; V. G. Malkovets; A. V. Travin; E. A. Belousova; V. V. Sharygin; Z. Konc

doi:10.1016/j.rgg.2012.06.004

The age of camptonite dikes of the Agardag alkali-basalt complex (western Sangilen): Results of Ar/Ar and U/Pb dating

A. A. Gibsher^*, V. G. Malkovets, A. V. Travin, E. A. Belousova, V. V. Sharygin, Z. Konc

^*Corresponding author for this work

ARC Centre of Excellence for Core to Crust Fluid Systems (incorporation ARC National Key Centre for Geochemical evolution and Metallogeny of Continents (GEMOC))

Research output: Contribution to journal › Article › peer-review

18 Citations (Scopus)

Abstract

A camptonite dike swarm (Agardag alkali-basalt complex) in the western part of the Sangilen Upland abounds in mantle xenoliths. Mineralogical, petrographic, and petrochemical studies show that the dikes are composed of lamprophyres of two groups, basic and ultrabasic. Ar/Ar dating of amphibole and phlogopite megacrysts gives an intrusion age for the dikes of 443.0 ± 1.3 Ma. ²⁰⁶Pb/ ²³⁸U dating of zircon from a glomeroporphyritic intergrowth in camptonite from one of the dikes yielded a core age of 489.0 ± 5.4 Ma. This corresponds to the time of formation of the Chzhargalanta granite-leucogranite complex (489.4 ± 2.6 Ma). The ²⁰⁶Pb/ ²³⁸U age of the zircon rim is 444.0 ± 7.5 Ma. The ages obtained by Ar/Ar dating of amphibole and biotite megacrysts and by U/Pb dating of the magmatic rim of zircon crystal from the camptonite coincide within the dating error, which indicates that the camptonite dikes formed in the Late Ordovician. These dikes are the oldest-known example of mantle-derived xenoliths in mafic volcanic rocks from an off-craton setting. These are samples of the Upper Ordovician lithospheric mantle.

Original language	English
Pages (from-to)	763-775
Number of pages	13
Journal	Russian Geology and Geophysics
Volume	53
Issue number	8
DOIs	https://doi.org/10.1016/j.rgg.2012.06.004
Publication status	Published - Aug 2012

Access to Document

10.1016/j.rgg.2012.06.004

Cite this

@article{49cb8845b4174f4cba8345f3dfd3a8c2,

title = "The age of camptonite dikes of the Agardag alkali-basalt complex (western Sangilen): Results of Ar/Ar and U/Pb dating",

abstract = "A camptonite dike swarm (Agardag alkali-basalt complex) in the western part of the Sangilen Upland abounds in mantle xenoliths. Mineralogical, petrographic, and petrochemical studies show that the dikes are composed of lamprophyres of two groups, basic and ultrabasic. Ar/Ar dating of amphibole and phlogopite megacrysts gives an intrusion age for the dikes of 443.0 ± 1.3 Ma. 206Pb/ 238U dating of zircon from a glomeroporphyritic intergrowth in camptonite from one of the dikes yielded a core age of 489.0 ± 5.4 Ma. This corresponds to the time of formation of the Chzhargalanta granite-leucogranite complex (489.4 ± 2.6 Ma). The 206Pb/ 238U age of the zircon rim is 444.0 ± 7.5 Ma. The ages obtained by Ar/Ar dating of amphibole and biotite megacrysts and by U/Pb dating of the magmatic rim of zircon crystal from the camptonite coincide within the dating error, which indicates that the camptonite dikes formed in the Late Ordovician. These dikes are the oldest-known example of mantle-derived xenoliths in mafic volcanic rocks from an off-craton setting. These are samples of the Upper Ordovician lithospheric mantle.",

author = "Gibsher, {A. A.} and Malkovets, {V. G.} and Travin, {A. V.} and Belousova, {E. A.} and Sharygin, {V. V.} and Z. Konc",

year = "2012",

month = aug,

doi = "10.1016/j.rgg.2012.06.004",

language = "English",

volume = "53",

pages = "763--775",

journal = "Russian Geology and Geophysics",

issn = "1068-7971",

publisher = "AMER GEOPHYSICAL UNION",

number = "8",

}

TY - JOUR

T1 - The age of camptonite dikes of the Agardag alkali-basalt complex (western Sangilen)

T2 - Results of Ar/Ar and U/Pb dating

AU - Gibsher, A. A.

AU - Malkovets, V. G.

AU - Travin, A. V.

AU - Belousova, E. A.

AU - Sharygin, V. V.

AU - Konc, Z.

PY - 2012/8

Y1 - 2012/8

N2 - A camptonite dike swarm (Agardag alkali-basalt complex) in the western part of the Sangilen Upland abounds in mantle xenoliths. Mineralogical, petrographic, and petrochemical studies show that the dikes are composed of lamprophyres of two groups, basic and ultrabasic. Ar/Ar dating of amphibole and phlogopite megacrysts gives an intrusion age for the dikes of 443.0 ± 1.3 Ma. 206Pb/ 238U dating of zircon from a glomeroporphyritic intergrowth in camptonite from one of the dikes yielded a core age of 489.0 ± 5.4 Ma. This corresponds to the time of formation of the Chzhargalanta granite-leucogranite complex (489.4 ± 2.6 Ma). The 206Pb/ 238U age of the zircon rim is 444.0 ± 7.5 Ma. The ages obtained by Ar/Ar dating of amphibole and biotite megacrysts and by U/Pb dating of the magmatic rim of zircon crystal from the camptonite coincide within the dating error, which indicates that the camptonite dikes formed in the Late Ordovician. These dikes are the oldest-known example of mantle-derived xenoliths in mafic volcanic rocks from an off-craton setting. These are samples of the Upper Ordovician lithospheric mantle.

AB - A camptonite dike swarm (Agardag alkali-basalt complex) in the western part of the Sangilen Upland abounds in mantle xenoliths. Mineralogical, petrographic, and petrochemical studies show that the dikes are composed of lamprophyres of two groups, basic and ultrabasic. Ar/Ar dating of amphibole and phlogopite megacrysts gives an intrusion age for the dikes of 443.0 ± 1.3 Ma. 206Pb/ 238U dating of zircon from a glomeroporphyritic intergrowth in camptonite from one of the dikes yielded a core age of 489.0 ± 5.4 Ma. This corresponds to the time of formation of the Chzhargalanta granite-leucogranite complex (489.4 ± 2.6 Ma). The 206Pb/ 238U age of the zircon rim is 444.0 ± 7.5 Ma. The ages obtained by Ar/Ar dating of amphibole and biotite megacrysts and by U/Pb dating of the magmatic rim of zircon crystal from the camptonite coincide within the dating error, which indicates that the camptonite dikes formed in the Late Ordovician. These dikes are the oldest-known example of mantle-derived xenoliths in mafic volcanic rocks from an off-craton setting. These are samples of the Upper Ordovician lithospheric mantle.

UR - http://www.scopus.com/inward/record.url?scp=84862985377&partnerID=8YFLogxK

U2 - 10.1016/j.rgg.2012.06.004

DO - 10.1016/j.rgg.2012.06.004

M3 - Article

AN - SCOPUS:84862985377

SN - 1068-7971

VL - 53

SP - 763

EP - 775

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

IS - 8

ER -

The age of camptonite dikes of the Agardag alkali-basalt complex (western Sangilen): Results of Ar/Ar and U/Pb dating

Abstract

Access to Document

Other files and links

Fingerprint

Cite this