Hydrocarbons and other volatile components in alkaline rocks from the Ukrainian shield and Kola Peninsula

Over recent years, new rare minerals have been discovered in the alkaline rocks of the Ukrainian Shield. Agpaitic varieties of alkaline magmatic and metasomatic rocks turned out to be especially abundant in rare minerals. Numerous findings are related to alkaline metasomatites which are considered to be fenites and apofenite albitites of the Dmytrivka quarry. It is well known primarily by the presence of various accessory (Nb, REE, and Zr) minerals, as well as silicate and oxide minerals that are rare for Ukraine. The most common albite microcline fenites of this quarry are characterized by rare-earth mineralization, whereas the concentration of REE decreases in apofenite albitites and Zr and Nb increase. New rare minerals were also found in the essentially albite rock with astrophyllite, alkaline pyroxene and amphibole of the Malatersa massif and agpaitic phonolites of the Oktyabrsky massif. In the rocks of the mentioned massifs and occurrences of alkaline rocks the most interesting are the findings of the perraultite — jinshajiangite series. They were found in three points of the Azov area and include 1) perraultite and jinshajiangite in the alkaline metasomatites of the Dmytrivka quarry; 2) only perraultite in agpaitic phonolites of the Oktyabrsky massif (Kam’yana gully); 3) jinshajiangite in a veined albite rock among the gabbro of the Malatersa massif. Baotite and minerals of the hejtmanite — bafertisite series were also found in the metasomatites of the Dmytrivka quarry. The latter belong to intermediate varieties in terms of MnO (10-17 wt.%) and FeO (10-17 wt.%) which distinguishes them from Fe-rich bafertisite from other regions. A silicate mineral with high content of Na, Zr, Mn and elevated Ti and Nb is rarely observed as small inclusions in the kupletskite grains from alkaline metasomatite of the Dmytrivka quarry. According to the chemical composition it was previously diagnosed as janhaugite. Tainiolite was found in some occurrences of alkaline metasomatites in the Azov region. In addition small aggregates of the REE-enriched epidote were found in fenites of the Kaplany village, which is probably the first finding in Ukraine. Two new Zr minerals have been found in the aegirine syenites of the Korsun-Novomyrhorod pluton: elpidite and mineral with a high content of Y2O3 (13-14 wt.%) (Y-hagatalite ?).

Download Full-text

Alkaline rocks of the eastern part of the Baltic Shield (Kola Peninsula)

Geological Society London Special Publications ◽

10.1144/gsl.sp.1987.030.01.26 ◽

1987 ◽

Vol 30 (1) ◽

pp. 531-544 ◽

Cited By ~ 11

Author(s):

L. N. Kogarko

Keyword(s):

Kola Peninsula ◽

Baltic Shield ◽

Alkaline Rocks ◽

The Baltic

Download Full-text

Alkaline rocks of the Ukrainian Shield: Some mineralogical, petrological and geochemical features

Mineralogia ◽

10.2478/mipo-2013-0008 ◽

2013 ◽

Vol 44 (3-4) ◽

pp. 115-124 ◽

Cited By ~ 2

Author(s):

Aleksandr N. Ponomarenko ◽

Stepan G. Kryvdik ◽

Aleksandr V. Grinchenko

Keyword(s):

Wide Distribution ◽

Ukrainian Shield ◽

Alkaline Magmatism ◽

Alkaline Rocks ◽

Precambrian Rocks ◽

Western Province ◽

Rock Types ◽

Alkaline Feldspar ◽

Granite Complex ◽

Proterozoic Age

AbstractThe Ukrainian Shield (USh) is a typical province of Proterozoic alkaline magmatism where about 50 massifs and occurrences of alkaline rocks and carbonatites have been found. In spite of the wide distribution of Devonian basaltic- and alkaline magmatic rocks in the Dnieper-Donetsk depression adjacent to the USh, and in a marginal zone of the USh adjacent to folded Donbass, only alkaline rocks of Proterozoic age (1.8-2.1 Ga) that have been identified in the central interior of the USh. Some discrete bodies of 2.8 Ga subalkaline rocks also occur in Bogdanivka massif (Azov area). Occurrences of both Proterozoic (prevailing) and Phanerozoic (Devonian) alkaline rocks and kimberlites are only found in the eastern part of the USh (Azov area). Kimberlites in the central part of the Ukrainian Shield (Kirovograd region) are also of Proterozoic age (ca 1.8 Ga). It is this predominance of Precambrian rocks that makes the USh so different from other alkaline provinces where Phanerozoic alkaline rocks and kimberlites commonly prevail over Precambrian rocks. The lack of Phanerozoic alkaline magmatism on USh is poorly understood. Two main complexes of alkaline rocks - alkaline-ultrabasic (carbonatitic) and gabbro- syenitic - are distinguished in the USh. There are also rare occurrences of rock types such as alkaline- and alkaline-feldspar granites that may represent one separate alkaline-granite complex. Alkaline rocks present in the Eastern (Azov) province and in the Western province display essentially different geochemical character. Those of the Eastern province show characteristics typical of alkaline-ultrabasic rocks (e.g. high contents of incompatible rare elementssuch as Nb, REE, Zr, Y, Sr, whereas those in the Western province are characterized by low contents of Nb and Zr, and REE in some cases. This fact is interpreted as reflecting different geodynamic conditions of their origin. The Eastern rocks were formed in rift settings, the Western rocks in crustal compressional settings (collision, subduction). Various mineral deposits of phosphorus (apatite), niobium, REE, yttrium and zirconium, including unusually rich ores of REE, Y and Zr (Azov and Yastrybetsky) are associated with the alkaline rocks and carbonatites of the USh.

Download Full-text

Geochemistry of Nb and Та in magmatic rocks of the Ukrainian Shield

Geochemistry and ore formation ◽

10.15407/gof.2020.41.012 ◽

2020 ◽

Vol 41 ◽

pp. 12-31

Author(s):

S.G. Kryvdik ◽

◽

O.V Dubyna ◽

◽

Keyword(s):

Igneous Rocks ◽

Ukrainian Shield ◽

Geochemical Data ◽

Alkaline Rocks ◽

Magmatic Rocks ◽

Azov Sea ◽

Continental Rifts ◽

Alkaline Feldspar ◽

High Concentrations ◽

Almost All

It was made an attempt to generalize geochemical data of Nb and Ta concentration in the most common igneous rocks of the Ukrainian Shield (USh). In the majority of widely distributed rocks of the USh (normal and subalkaline granitoids) the Nb and Ta concentration are similar to upper crust but lower the accepted Clark value for acidic rocks. In the more differentiated rapakivi granites concentrations of these elements reach or exceed the Clark’s concentrations (up to 35 ppm). Only highly differentiated alkaline rocks and alkaline feldspar granites (Perga, Kamiani mogyly, Ruska Poliana massifs) have high Nb concentrations (up to 800, 120 and 370 ppm, respectively). Medium rocks of the normal range are the least geochemically studied and typically are characterized low Nb and Ta concentrations. Almost all gabbroids as well as their metamorphosed analogues in the greenstone structures, are characterized by very low Nb (and Ta) concentration (two or more orders of magnitude) compared with Clark’s values for basic rocks (20 ppm Nb and 0.48 ppm Ta) according to A.P. Vinogradov. Against this background, increased of Nb and Ta concentration is observed in the main rocks of anorthosite-rapakivi-granite plutons. Howover even in these rocks concentration of these elements rarely reach or does not achieve the values which are typical for subalkaline and alkaline basalts of continental rifts. The regional heterogeneity in Nb and Ta distribution is observed in alkaline rocks of different composition: in the Azov Sea region these rocks are characterized by high concentrations, while in the western part of the USh the content of these elements is extremely low. The increased concentration of these elements is also revealed in kimberlites from the Azov Sea region and the Kyrovohrad megablock of the USh. The authors give some considerations and assumptions about the dependence on geochemical features of the Precambrian igneous rocks of the USh from the geodynamic conditions of their formation.

Download Full-text

The Proskurov massif of alkaline rocks (Ukrainian shield): new geochemical database

Visnyk of Taras Shevchenko National University of Kyiv Geology ◽

10.17721/1728-2713.72.04 ◽

2016 ◽

pp. 28-34

Author(s):

S. Shnyukov ◽

◽

V. Osypenko ◽

Keyword(s):

Ukrainian Shield ◽

Alkaline Rocks

Download Full-text

On the participation of natural salts in alkaline magmatism. Article 3. Genetic aspects of the model of salt-alkaline interactions

LITOSFERA ◽

10.24930/1681-9004-2021-21-2-172-197 ◽

2021 ◽

Vol 21 (2) ◽

pp. 172-197

Author(s):

G. A. Belenitskaya

Keyword(s):

Genetic Model ◽

Black Shales ◽

Volatile Components ◽

Alkaline Magmatism ◽

Upward Movement ◽

Alkaline Salt ◽

Alkaline Rocks ◽

Positive Assessment ◽

Probable Role ◽

Spatio Temporal

Research subject. An analysis of regional and global geological material characterizing the spatio-temporal relationships between alkaline magmatic and saline complexes allowed the author to propose and justify a new geological-genetic model of alkaline magmatism. This model considers saline complexes, located along the paths of the upward movement of deep magmas, as additional sources of alkaline and volatile components.Materials and methods. Three articles are devoted to the discussion and justification of this model. Two articles were devoted to geological aspects of the problem. The prerequisites and signs of the participation of ancient saline complexes in alkaline magmatism were characterized. It was shown that the presence of saline rocks in the deep zones of the earth's crust along the paths of the upward movement of deep magma flows is a geologically natural and common phenomenon. Natural alkaline-salt associations (spatio-temporal combinations of alkaline and salt objects) were indicated; their tectonic types were distinguished. A global overview of their different-age analogues (neo- and paleogeodynamic) was given.Results and discussion. The collected data made it possible to evaluate older (than magmas) salt-bearing complexes (deeply buried in the substrate) as a possible important and active participant in the ontogenesis of alkaline complexes, to give a positive assessment of the geological aspects of the “magma halocontamination” model and salt-magmatic interactions; to formulate the main geological-genetic provisions of this model.Conclusion. This article focuses on the discussion of the genetic aspects of the proposed model with an assessment of the probable role and significance of various halophilic components in the formation of alkaline magmas and their features. For this purpose, the similarity features in the spatial and quantitative distribution of halophilic and foydaphilic components in salt and alkaline rocks are considered; the probable role of various halophilic components in the formation of alkaline specialization of magmas, in the emergence of a rich set of unusual features of alkaline rocks (material, structural, morphological, etc.) is discussed. The probability of participation of the complex of paragenic (non-salt) members of the halophilic community (dolomites, anhydrites, black shales and associated ore components) in the interaction with hot magma is estimated. A comparative analysis of some basic provisions of the model under consideration with other geological-genetic models of alkaline petrogenesis is performed. The advantages of this model and its predictive capabilities are evaluated. A number of ideas have been proposed by the author for the first time, thus requiring further elucidation.

Download Full-text