Petrology of foiditic and meymechitic volcanism in the Maimecha-Kotui province (Polar Siberia). / Vasil'ev, Yu R.; Gora, M. P.; Kuz'min, D. V.
In: Russian Geology and Geophysics, Vol. 58, No. 6, 01.06.2017, p. 659-673.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Petrology of foiditic and meymechitic volcanism in the Maimecha-Kotui province (Polar Siberia)
AU - Vasil'ev, Yu R.
AU - Gora, M. P.
AU - Kuz'min, D. V.
PY - 2017/6/1
Y1 - 2017/6/1
N2 - Comparative analysis of ultramafic meymechites of the Maimecha Suite and alkaline volcanics of the Ary-Dzhang Suite (foidites (nephelinites, analcimites, limburgites, etc.) and melilitites) has shown their consanguinity, which indicates their relationship with the same magmatic system periodically producing large amounts of alkaline ultramafic melts. We have studied the petrogeochemical and mineralogical compositions of rocks and melt inclusions in the hosted olivines. The rocks of the Maimecha and Ary-Dzhang Suite differ considerably in MgO content, which is well explained by the accumulation of olivine. The inclusions in olivines from the meymechites and the rocks of the Ary-Dzhang Suite correspond in composition to foidites. The trace and rare-earth element patterns are similar both in the foidites and meymechites and in the melt inclusions: They show negative anomalies of Rb and K and positive anomalies of Nb and Ta. The ratios of indicator elements (Nb/Ta, Ba/La, Ta/La, etc.) in the rocks of the Maimecha and Ary-Dzhang Suite are constant and almost independent of their Mg# values. The La/Yb ratio in the foidites is significantly higher than that in the meymechites and in the melt inclusions from their olivines, which indicates that the rocks of the Ary-Dzhang Suite resulted from the fractionation of highly magnesian alkaline picritoid melt.
AB - Comparative analysis of ultramafic meymechites of the Maimecha Suite and alkaline volcanics of the Ary-Dzhang Suite (foidites (nephelinites, analcimites, limburgites, etc.) and melilitites) has shown their consanguinity, which indicates their relationship with the same magmatic system periodically producing large amounts of alkaline ultramafic melts. We have studied the petrogeochemical and mineralogical compositions of rocks and melt inclusions in the hosted olivines. The rocks of the Maimecha and Ary-Dzhang Suite differ considerably in MgO content, which is well explained by the accumulation of olivine. The inclusions in olivines from the meymechites and the rocks of the Ary-Dzhang Suite correspond in composition to foidites. The trace and rare-earth element patterns are similar both in the foidites and meymechites and in the melt inclusions: They show negative anomalies of Rb and K and positive anomalies of Nb and Ta. The ratios of indicator elements (Nb/Ta, Ba/La, Ta/La, etc.) in the rocks of the Maimecha and Ary-Dzhang Suite are constant and almost independent of their Mg# values. The La/Yb ratio in the foidites is significantly higher than that in the meymechites and in the melt inclusions from their olivines, which indicates that the rocks of the Ary-Dzhang Suite resulted from the fractionation of highly magnesian alkaline picritoid melt.
KW - Arctic Siberia
KW - foidites
KW - Maimecha-Kotui province
KW - melt inclusions
KW - meymechites
KW - CRYSTALLIZATION
KW - ROCKS
KW - MEIMECHITES
KW - MANTLE
KW - ALKALINE PICRITES
KW - MASSIF
KW - ORIGIN
KW - EVOLUTION
KW - DIFFERENTIATION
KW - MAGMAS FORMATION
UR - http://www.scopus.com/inward/record.url?scp=85020307061&partnerID=8YFLogxK
U2 - 10.1016/j.rgg.2017.05.001
DO - 10.1016/j.rgg.2017.05.001
M3 - Article
AN - SCOPUS:85020307061
VL - 58
SP - 659
EP - 673
JO - Russian Geology and Geophysics
JF - Russian Geology and Geophysics
SN - 1068-7971
IS - 6
ER -
ID: 10186813