The 1501 Ma Kuonamka Large Igneous Province of northern Siberia : U-Pb geochronology, geochemistry, and links with coeval magmatism on other crustal blocks
(2016) In Russian Geology and Geophysics 57(5). p.653-671- Abstract
A new large igneous province (LIP), the 1501 ± 3 Ma Kuonamka LIP, extends across 700 km of northern Siberia and is linked with coeval dikes and sills in the formerly attached Sao Francisco craton (SFC)-Congo craton to yield a short-duration event 2000 km across. The age of the Kuonamka LIP can be summarized as 1501 ± 3 Ma (95% confidence), based on 7 U-Pb ID-TIMS ages (6 new herein) from dolerite dikes and sills across the Anabar shield and within western Riphean cover rocks for a distance of 270 km. An additional sill yielded a SIMS (CAMECA) age of 1483 ± 17 Ma and sill in the Olenek uplift several hundred kilometers farther east, a previous SIMS (SHRIMP) age of ca. 1473 Ma was obtained on a sill; both SIMS ages are within the age... (More)
A new large igneous province (LIP), the 1501 ± 3 Ma Kuonamka LIP, extends across 700 km of northern Siberia and is linked with coeval dikes and sills in the formerly attached Sao Francisco craton (SFC)-Congo craton to yield a short-duration event 2000 km across. The age of the Kuonamka LIP can be summarized as 1501 ± 3 Ma (95% confidence), based on 7 U-Pb ID-TIMS ages (6 new herein) from dolerite dikes and sills across the Anabar shield and within western Riphean cover rocks for a distance of 270 km. An additional sill yielded a SIMS (CAMECA) age of 1483 ± 17 Ma and sill in the Olenek uplift several hundred kilometers farther east, a previous SIMS (SHRIMP) age of ca. 1473 Ma was obtained on a sill; both SIMS ages are within the age uncertainty of the ID-TIMS ages. Geochemical data indicate a tholeiitic basalt composition with low MgO (4-7 wt%) within-plate character based on trace element classification diagrams and source between E-MORB and OIB with only minor contamination from crust or metasomatized lithospheric mantle. Two subgroups are distinguished: Group 1 has gently sloping LREE ((La/Sm)PM = 1.9) and HREE ((Gd/Yb)PM = 1.8) patterns, slightly negative Sr and moderate TiO2 (2.2 wt%), and Group 2 has steeper LREE ((La/Sm)PM = 2.3) and HREE ((Gd/Yb)PM = 2.3), strong negative Sr anomaly, is higher in TiO2 (2.7 wt%), and is transitional from tholeiitic to weakly alkaline in composition. The slight differences in REE slopes are consistent with Group 2 on average melting at deeper levels. Proposed reconstructions of the Kuonamka LIP with 1500 Ma magmatism of the SFC-Congo craton are supported by a geochemical comparison. Specifically, the chemistry of the Chapada Diamantina and Curaga dikes of the SFC can be linked to that of Groups 1 and 2, respectively, of the Kuonamka LIP and are consistent with a common mantle source between EMORB and OIB and subsequent differentiation history. However, the coeval Humpata sills and dikes of the Angola block of the Congo craton represent a different magma batch.
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- author
- Ernst, R. E. ; Okrugin, A. V. ; Veselovskiy, R. V. ; Kamo, S. L. ; Hamilton, Michael A. ; Pavlov, V. ; Soderlund, U. LU ; Chamberlain, Kevin R. and Rogers, Chad N
- organization
- publishing date
- 2016-05-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Dikes, Igneous province, Magmatism, Northern Siberia, Sills
- in
- Russian Geology and Geophysics
- volume
- 57
- issue
- 5
- pages
- 19 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:84969804367
- wos:000377370700003
- ISSN
- 1068-7971
- DOI
- 10.1016/j.rgg.2016.01.015
- language
- English
- LU publication?
- yes
- id
- fb454823-dfa7-4b7b-b718-620e5e70870c
- date added to LUP
- 2017-02-02 14:15:29
- date last changed
- 2024-02-19 16:13:48
@article{fb454823-dfa7-4b7b-b718-620e5e70870c,
abstract = {{<p>A new large igneous province (LIP), the 1501 ± 3 Ma Kuonamka LIP, extends across 700 km of northern Siberia and is linked with coeval dikes and sills in the formerly attached Sao Francisco craton (SFC)-Congo craton to yield a short-duration event 2000 km across. The age of the Kuonamka LIP can be summarized as 1501 ± 3 Ma (95% confidence), based on 7 U-Pb ID-TIMS ages (6 new herein) from dolerite dikes and sills across the Anabar shield and within western Riphean cover rocks for a distance of 270 km. An additional sill yielded a SIMS (CAMECA) age of 1483 ± 17 Ma and sill in the Olenek uplift several hundred kilometers farther east, a previous SIMS (SHRIMP) age of ca. 1473 Ma was obtained on a sill; both SIMS ages are within the age uncertainty of the ID-TIMS ages. Geochemical data indicate a tholeiitic basalt composition with low MgO (4-7 wt%) within-plate character based on trace element classification diagrams and source between E-MORB and OIB with only minor contamination from crust or metasomatized lithospheric mantle. Two subgroups are distinguished: Group 1 has gently sloping LREE ((La/Sm)<sub>PM</sub> = 1.9) and HREE ((Gd/Yb)<sub>PM</sub> = 1.8) patterns, slightly negative Sr and moderate TiO<sub>2</sub> (2.2 wt%), and Group 2 has steeper LREE ((La/Sm)<sub>PM</sub> = 2.3) and HREE ((Gd/Yb)<sub>PM</sub> = 2.3), strong negative Sr anomaly, is higher in TiO<sub>2</sub> (2.7 wt%), and is transitional from tholeiitic to weakly alkaline in composition. The slight differences in REE slopes are consistent with Group 2 on average melting at deeper levels. Proposed reconstructions of the Kuonamka LIP with 1500 Ma magmatism of the SFC-Congo craton are supported by a geochemical comparison. Specifically, the chemistry of the Chapada Diamantina and Curaga dikes of the SFC can be linked to that of Groups 1 and 2, respectively, of the Kuonamka LIP and are consistent with a common mantle source between EMORB and OIB and subsequent differentiation history. However, the coeval Humpata sills and dikes of the Angola block of the Congo craton represent a different magma batch.</p>}},
author = {{Ernst, R. E. and Okrugin, A. V. and Veselovskiy, R. V. and Kamo, S. L. and Hamilton, Michael A. and Pavlov, V. and Soderlund, U. and Chamberlain, Kevin R. and Rogers, Chad N}},
issn = {{1068-7971}},
keywords = {{Dikes; Igneous province; Magmatism; Northern Siberia; Sills}},
language = {{eng}},
month = {{05}},
number = {{5}},
pages = {{653--671}},
publisher = {{Elsevier}},
series = {{Russian Geology and Geophysics}},
title = {{The 1501 Ma Kuonamka Large Igneous Province of northern Siberia : U-Pb geochronology, geochemistry, and links with coeval magmatism on other crustal blocks}},
url = {{http://dx.doi.org/10.1016/j.rgg.2016.01.015}},
doi = {{10.1016/j.rgg.2016.01.015}},
volume = {{57}},
year = {{2016}},
}