Mafic Dyke Records of Paleoproterozoic Mantle Plume Activity in the Karelian Craton: U-Pb Baddeleyite/Zircon Geochronology and Sr-Nd Isotopic Data

2016 ◽  
Vol 90 (s1) ◽  
pp. 118-119
Author(s):  
A.V. Samsonov ◽  
A.V. Stepanova ◽  
E.B. Salnikova ◽  
Yu.O. Larionova ◽  
S.V. Egorova ◽  
...  
Keyword(s):  
Mantle Plume ◽  
Zircon Geochronology ◽  
Mafic Dyke ◽  
Isotopic Data ◽  
Karelian Craton

Ultramafic-alkaline-carbonatite complexes as a result of two-stage melting of mantle plume: evidence from the mid-paleoproterozoic Tiksheozero intrusion, Northern Karelia, Russia

2019 ◽  
Vol 486 (4) ◽  
pp. 460-465
Author(s):  
E. V. Sharkov ◽  
A. V. Chistyakov ◽  
M. M. Bogina ◽  
O. A. Bogatikov ◽  
V. V. Shchiptsov ◽  
...  
Keyword(s):  
Fractional Crystallization ◽  
Mantle Plume ◽  
Large Igneous Province ◽  
Intrusive Complex ◽  
Incongruent Melting ◽  
Isotopic Data ◽  
Two Stage ◽  
Similar Composition ◽  
Igneous Province ◽  
Alkaline Magmas

Tiksheozero ultramafic-alkaline-carbonatite intrusive complex, like numerous carbonatite-bearing complexes of similar composition, is a part of large igneous province, related to the ascent of thermochemical mantle plume. Our geochemical and isotopic data evidence that ultramafites and alkaline rocks are joined by fractional crystallization, whereas carbonatitic magmas has independent origin. We suggest that origin of parental magmas of the Tiksheozero complex, as well as other ultramafic-alkaline-carbonatite complexes, was provided by two-stage melting of the mantle-plume head: 1) adiabatic melting of its inner part, which produced moderately-alkaline picrites, which fractional crystallization led to appearance of alkaline magmas, and 2) incongruent melting of the upper cooled margin of the plume head under the influence of CO2-rich fluids  that arrived from underlying zone of adiabatic melting gave rise to carbonatite magmas.

Geochemistry and U-Pb geochronology of 1590 and 1550 Ma mafic dyke swarms of western Laurentia: Mantle plume magmatism shared with Australia

Lithos ◽  
2018 ◽  
Vol 314-315 ◽  
pp. 216-235 ◽  
Author(s):  
C. Rogers ◽  
S.L. Kamo ◽  
U. Söderlund ◽  
M.A. Hamilton ◽  
R.E. Ernst ◽  
...  
Keyword(s):  
Mantle Plume ◽  
Mafic Dyke ◽  
Plume Magmatism ◽  
Dyke Swarms

The 2405 Ma and 2310 Ma Mafic Dyke Swarms in the Karelian Craton: Age, Chemical and Sr-Nd Isotope Composition, and Tectonic Setting

2016 ◽  
Vol 90 (s1) ◽  
pp. 123-123
Author(s):  
A.V. Stepanova ◽  
E.B. Salnikova ◽  
A.V. Samsonov ◽  
Yu.O. Larionova ◽  
S.V. Egorova ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Tectonic Setting ◽  
Mafic Dyke ◽  
Karelian Craton ◽  
Nd Isotope ◽  
Dyke Swarms ◽  
Nd Isotope Composition

scholarly journals Mantle sources of Cenozoic volcanic activities around the South China Sea revealed by geochemical and isotopic data using the principal component analysis (PCA)

2021 ◽  
Author(s):  
Shuangshuang Chen ◽  
Zewei Wang ◽  
Rui Gao
Keyword(s):  
Principal Component Analysis ◽  
South China Sea ◽  
Mantle Plume ◽  
South China ◽  
Principal Component ◽  
Component Analysis ◽  
Isotopic Data ◽  
Mantle Sources ◽  
Basalt Type ◽  
Volcanic Activities

Abstract Principal component analysis (PCA) was conducted to analyze geochemical and isotopic data and interpret the characteristics and types of mantle sources of Cenozoic volcanic activities around the South China Sea (SCS). Fifteen trace element indicators and five isotopic indicators were surveyed from 623 volcanic rock samples obtained from the SCS, Hainan Island, Fujian–Zhejiang, Taiwan, Vietnam, and Thailand to characterize the geochemical properties of the volcanic rocks, determine the types of mantle sources, and assess the influence degree of each mantle source. Two principal components (PCs) were extracted by PCA based on trace elements and Sr–Nd–Pb isotopic ratios, which are an enriched oceanic island basalt-type mantle plume and a depleted mid-ocean ridge basalt-type spreading ridge. In the Southeast Asian region, the influence of Hainan mantle plume on younger volcanic activities (< 13 Ma) was greater than that on older ones (> 13 Ma) in the same location. PCA was used to verify the mantle plume–ridge interaction model of volcanic activities beneath the expansion center of the SCS and refute the hypothesis that the tension in the SCS is triggered by the Hainan plume. The results of this study demonstrate the efficiency and applicability of PCA to the discussion of mantle sources of volcanic activities and provide a new method with which to analyze geochemical data.

Determination of contribution from the metachronous components of magnetization to the Precambrian paleomagnetic of the Karelian craton

2018 ◽  
pp. 3-13
Author(s):  
N. V. Lubnina ◽  
V. S. Zakharov
Keyword(s):  
High Temperature ◽  
Isotopic Data ◽  
Karelian Craton ◽  
Secondary Origin ◽  
The Mean ◽  
Paleomagnetic Poles ◽  
High Temperature Components ◽  
Vector Sum ◽  
True Direction

The secondary (metachronous) component of magnetization isolated in the Precambrian complexes of the Karelian craton have been analyzed. The mean directions of high temperature components (deviations from the true direction) depending on the contribution of secondary magnetization components resulting from uneven-aged tectono-magmatic events. It has been shown that the Precambrian key poles often coincide with the vector sum of the ages of Phanerozoic component of magnetization. The conclusion about the primary/secondary origin of the Precambrian paleomagnetic poles must be set on the basis of the integrated petro-paleomagnetic and isotopic data and geological correlations, not only tests of paleomagnetic reliability.

Giant radiating mafic dyke swarm of the Emeishan Large Igneous Province: Identifying the mantle plume centre

Terra Nova ◽  
2015 ◽  
Vol 27 (4) ◽  
pp. 247-257 ◽  
Author(s):  
Hongbo Li ◽  
Zhaochong Zhang ◽  
Richard Ernst ◽  
Linsu Lü ◽  
M. Santosh ◽  
...  
Keyword(s):  
Mantle Plume ◽  
Large Igneous Province ◽  
Dyke Swarm ◽  
Mafic Dyke ◽  
Emeishan Large Igneous Province ◽  
Igneous Province ◽  
Mafic Dyke Swarm

U–Pb zircon geochronology of Lower Jurassic and Paleozoic Stikinian strata and Tertiary intrusions, northwestern British Columbia

1995 ◽  
Vol 32 (8) ◽  
pp. 1155-1171 ◽  
Author(s):  
C. J. Greig ◽  
G. E. Gehrels
Keyword(s):  
Volcanic Rocks ◽  
Lower Jurassic ◽  
Detrital Zircons ◽  
Zircon Geochronology ◽  
Fold Belt ◽  
Isotopic Data ◽  
The West ◽  
Juvenile Crust ◽  
Felsic Volcanic ◽  
Felsic Volcanic Rocks

New U–Pb zircon ages are reported from western Stikinia. Devonian and Pennsylvanian ages of volcanic rocks at Oweegee dome confirm the presence of pre-Permian strata, and with Paleozoic and Triassic detrital zircons from Lower Jurassic sandstone, they help to demonstrate pre-Lower Jurassic deformation and uplift. The absence of pre-Paleozoic inherited zircon from all samples is consistent with Nd–Sr isotopic data which suggest that Stikinia consists mainly of juvenile crust. U–Pb ages for posttectonic intrusions suggest that structures in Skeena Fold Belt in the Kinskuch area formed prior to Eocene time. Five ages for felsic volcanic rocks from stratigraphically well-constrained upper parts of the Hazelton arc are approximately 196–199 Ma and suggest near-contemporaneity for cessation of volcanism in the areas studied. The Sinemurian or late Sinemurian – early Pliensbachian ages are older than previously reported U–Pb and biostratigraphic ages for presumed correlative rocks to the west, and westward-migrating volcanism is implied. Together with Toarcian fossils from overlying sandstone, the new ages suggest that a hiatus of moderate duration preceded regionally extensive sedimentation.

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