TY - JOUR

T1 - Stages of Trap Magmatism in the Norilsk Area

T2 - New Data on the Structure and Geochemistry of the Volcanic Rocks

AU - Krivolutskaya, N. A.

AU - Kuzmin, D. V.

AU - Gongalsky, B. I.

AU - Roshchina, I. A.

AU - Kononkova, N. N.

AU - Svirskaya, N. M.

AU - Romashova, T. V.

PY - 2018/5/1

Y1 - 2018/5/1

N2 - A periodic character of the evolution of trap magmatism was inferred by many researchers from the fact that sequences of volcanic rocks consist of alternating units of lava flows and tuff. A new phase of studying magmatic rocks in the Siberian Platform was related to the possibility of apply high-precision geochemical techniques in studying trace elements and Sr, Nd, and Pb isotopic compositions. The use of these techniques made it possible not only to identify small individual cycles in the vertical sections of volcanic rocks but also to distinguish larger stages. The currently most widely acknowledged scenario of the origin of volcanic rocks involves three stages, during which oceanic-island basalts (OIB), transitional series (intermediate between OIB and WPB), and within-plate basalts (WPB) were formed. This scenario was inferred mostly from data on rocks in the western part of the Norilsk area (Kharaelakh Trough). This publication presents recently obtained data on the inner structure of the sequences of volcanic rocks and the geochemistry of basalts in the eastern part of the territory, where no rocks show transitional characteristics have ever been found. They can be classified into two types that have clearly different composition and occur in different areas. These types characterize two major stages of the origin of volcanic rocks: rift-related and trap magmatism itself. The rocks produced during these stages occur at neighboring territories.

AB - A periodic character of the evolution of trap magmatism was inferred by many researchers from the fact that sequences of volcanic rocks consist of alternating units of lava flows and tuff. A new phase of studying magmatic rocks in the Siberian Platform was related to the possibility of apply high-precision geochemical techniques in studying trace elements and Sr, Nd, and Pb isotopic compositions. The use of these techniques made it possible not only to identify small individual cycles in the vertical sections of volcanic rocks but also to distinguish larger stages. The currently most widely acknowledged scenario of the origin of volcanic rocks involves three stages, during which oceanic-island basalts (OIB), transitional series (intermediate between OIB and WPB), and within-plate basalts (WPB) were formed. This scenario was inferred mostly from data on rocks in the western part of the Norilsk area (Kharaelakh Trough). This publication presents recently obtained data on the inner structure of the sequences of volcanic rocks and the geochemistry of basalts in the eastern part of the territory, where no rocks show transitional characteristics have ever been found. They can be classified into two types that have clearly different composition and occur in different areas. These types characterize two major stages of the origin of volcanic rocks: rift-related and trap magmatism itself. The rocks produced during these stages occur at neighboring territories.

KW - magmatism

KW - Norilsk district

KW - Siberian Platform

KW - trace elements

KW - traps

UR - http://www.scopus.com/inward/record.url?scp=85046530962&partnerID=8YFLogxK

U2 - 10.1134/S0016702918050026

DO - 10.1134/S0016702918050026

M3 - Article

AN - SCOPUS:85046530962

VL - 56

SP - 419

EP - 437

JO - Geochemistry International

JF - Geochemistry International

SN - 0016-7029

IS - 5

ER -