Petrographical and Geochemical Characteristics of Magmatic Rocks in the Northwestern Siberian Traps Province, Kulyumber River Valley. Part II: Rocks of the Kulyumber Site (original) (raw)
Related papers
Minerals
The origin of the Siberian Traps province has been under discussion for the last three decades. Up to now, there is no real model of its formation in a good agreement with geological data on the magmatic evolution at P–T boundary in Eastern Siberia. Modern geochemical data on magmatic rocks around the province is a key to reconstructing magmatic development in time and space. Such data have been obtained for the Norilsk and Meimecha–Kotuy and not for other parts of the Siberian province. For the first time, we studied the geochemistry and mineralogy of magmatic rocks at the Kulyumber river valley, located in the intersection of the Tunguska syneclise and Norilsk–Igarka zone in the NW Siberian platform. In this article, we present data from the Khalil and Kaya sites of this area belonging to the Syverminsky, Gudchikhinsky, Khakanchansky and Nadezhdinsky formations. Their mineralogical and geochemical features (including Sr, Nd and Pb isotope data) are similar to the same formations i...
IOP Conference Series: Earth and Environmental Science
To understand the origin of the Siberian trap province, it is necessary to know its internal structure in detail. Only two areas were described, the Noril'sk and Maimecha-Kotuy, while the most important part of the province, the Tunguska syneclise, is still poorly characterized. The main goal of our study is an investigation of the structure and geochemistry of volcanic rocks located in the central part of the province. We have studied basalts and tuffs and compared them with the rocks of the Noril'sk area. All studied rocks belong to three formations: Korvunchansky, Nidymsky and Kochechumsky. The whole thickness of this crosssection is around 1,000 m. Our geochemical data demonstrate that the lower part of the crosssection comprises basalts with TiO2 =1 wt% while the upper part consists of the basalts with the average TiO2 content 1.4-1.5wt%. Based on this data, these rocks can be correlated with Morongovsky and Mokulaevsky formations located in the Noril'sk area. Despite many similarities between the volcanic rocks of these two areas, the basalts and tuffs of the Tunguska syneclise have their specific features, i.e. many tuff horizons, small thickness of flows and their poikiloophitic structure that reflect the rock formation near the boundary of the Tunguska syneclise.
Magmatism evolution in the Nori'lsk region (Siberian trap province)
2010
The NW Siberian trap province is very important for our understanding of evolution of huge magmatic system (T1) and origin unique Pt-Cu-Ni deposits. To solve these genetic problems (including correlation between effusive and intrusive rocks) it is necessary to get accurate information about magmatism migration in space and in time inside different tectonic structures in the Noril'sk region. Thed latter takes outstanding place on the Siberian platform due to its geological features. It consists of two main areas covered by volcanic rocks: I. Kharaelakhsky trough (on West) and II. plateau Putorana (on East) are subdivided by carbonate-terrigenouse rocks (C-P2) of Khantaisko-Rybninsky swell . These two zones differ one from another by thickness of basalts and their composition.The fist zone extents along the Khatanga fault and contains all suits, including three lowest ones - ivakinsky (Iv), syverminsky (Sv), gudchikhinsky (Gd). II zone essentially consists of the middle and upper...
Geochemistry International, 2018
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.
Geochemistry and Geochronology of Southern Norilsk Intrusions, SW Siberian Traps
Minerals
The Norilsk ore region is characterized by the occurrence of numerous intrusions comprising the PGE–Cu–Ni deposits. The Turumakit area, within the Southern Norilsk Trough, also contains many mineralized mafic intrusions of probably similar economic potential to the known Norilsk deposits. We study igneous rocks from three boreholes within the Turumakit area, sampling gabbro-dolerites and trachydolerites related to the Norilsk and Ergalakh complexes, as well as an outcrop of the Daldykan gabbro-dolerite intrusion. Our petrographical, mineralogical and geochemical data, as well as the U–Pb dating of extracted baddeleyites and zircons, primarily discriminate between the sub-alkaline rocks of the main Turumakit area and the Ergalakh trachydolerites located in the Norilsk and Talnakh ore junctions. Coarser grained Turumakit trachydolerites (with pegmatite segregations) contrast finer grained Ergalakh trachydolerites by having: (1) higher TiO2 (up to 5.5 wt %) compared with 2.2 wt %–3.3 w...
Journal of Chemistry and Chemical Engineering, 2014
This paper discusses the vein rocks located in the central part of Khibina Mts.. These rocks are located on the border of two zones: ore and external. In the ore, zone is present titanite-nepheline bodies whilst in the outer zone are massive-syenites "khibinites". The veins can be divided into: mikrosyenites, melteigites and other rock types (e.g., tinguaites). The results of LA-ICP MS (laser ablation of inductively coupled plasma mass spectrometry) indicate that these rocks are associated with deep zones which formed as a result of injection of primary magma and contamination of fluids during migration, where there have hydrothermal processes. Rock-forming minerals, their corrosion and accessory minerals indicate these processes, too.
Геология и геофизика, 2016
A new large igneous province, 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 São Francisco craton (SFC)-Congo craton to yield a short duration LIP 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 into the western Riphean cover rocks for a distance of 270 km. An additional sill yielded a SIMS (CAMECA) age of 1483 ± 17 Ma and in the Olenek uplift several hundred kilometres 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 TiO 2 (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 TiO 2 (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 Curaça dikes of the SFC are similar to the 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.