dc.contributor.author |
Ernst R. |
|
dc.contributor.author |
Okrugin A. |
|
dc.contributor.author |
Veselovskiy R. |
|
dc.contributor.author |
Kamo S. |
|
dc.contributor.author |
Hamilton M. |
|
dc.contributor.author |
Pavlov V. |
|
dc.contributor.author |
Soderlund U. |
|
dc.contributor.author |
Chamberlain K. |
|
dc.contributor.author |
Rogers C. |
|
dc.date.accessioned |
2018-09-19T20:58:11Z |
|
dc.date.available |
2018-09-19T20:58:11Z |
|
dc.date.issued |
2016 |
|
dc.identifier.issn |
1068-7971 |
|
dc.identifier.uri |
https://dspace.kpfu.ru/xmlui/handle/net/143471 |
|
dc.description.abstract |
© 2015.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. |
|
dc.relation.ispartofseries |
Russian Geology and Geophysics |
|
dc.subject |
Dikes |
|
dc.subject |
Igneous province |
|
dc.subject |
Magmatism |
|
dc.subject |
Northern Siberia |
|
dc.subject |
Sills |
|
dc.title |
The 1501 Ma Kuonamka Large Igneous Province of northern Siberia: U-Pb geochronology, geochemistry, and links with coeval magmatism on other crustal blocks |
|
dc.type |
Article |
|
dc.relation.ispartofseries-issue |
5 |
|
dc.relation.ispartofseries-volume |
57 |
|
dc.collection |
Публикации сотрудников КФУ |
|
dc.relation.startpage |
653 |
|
dc.source.id |
SCOPUS10687971-2016-57-5-SID84969804367 |
|