News Registration Abstract submission Deadlines Excursions Accommodation Organizing committee
First circular Second circular Abstracts Seminar History Program Travel Contact us
Первый циркуляр
Второй циркуляр
Оформление тезисов
Важные даты
Обратная связь

Тезисы международной конференции

Рудный потенциал щелочного, кимберлитового

 и карбонатитового магматизма

Abstracts of International conference

Ore potential of alkaline, kimberlite

and carbonatite magmatism

Petrochemical features of magmatites in various zones of Proterozoic subduction of Ukrainian Shield

 Agarkova N.G., Setaya L.D., Sheremet Ye.M.

 Ukrainian State Research and Design Institute of Mining Geology, Rock Mechanics and Mine Surveying (UkrNIMI) of the National Academy of Sciences of Ukraine (NANU), Donetsk, Ukraine



Petrochemical features of Proterozoic magmatites from initial to final stages in different geoblocks of Ukrainian Shield are considered from the view point of plate tectonics.

The whole Ukrainian Shield, as regards features of its geodynamic settings in Proterozoic, is divided into east part (Priazovsky megablock), central part (West Inguletsko-Krivorozhsko-Kremenchugskaya suture zone – WIKKSZ), Inguletsky megablock and Golovanevskaya suture zone – GSZ), west part (Belotserkovsko-Bugsky megablock, Nemirovsko-Kocherovskaya suture zone (NKSZ), and Volyno-Podolsky megablock) (Sheremet et al., 2011).

East part of Ukrainian Shield (Priazovsky megablock)

Based on the diagram of petrochemical compositions of magmatic rocks (Classification…, 1981) that shows values of average composition of intrusive complexes of the Priazovie, the west part of subduction zone (West Priazovie) is characterized by calc-alkali composition of magmatites and the east part (Central and East Priazovie) ‑ by sub-alkali and alkali. Existence in West Priazovie of magmatites of sub-alkali composition (Saltychansk and Chernigov complexes) speaks, probably, that in the process of initial movement of the plate under the Priazovsky megablock, together with triggering of palingenic magmatism, there were deep cracks down to the mantle along which carbonatite magma intruded. They were also channels for conducting heat and fluids carried chemical (more alkali) moving components and REE into upper layers of the earth’s crust, in palingenesis of which Saltychansk orthite granites have formed.

Central part of Ukrainian Shield

WIKKSZ. Gabbro-monzonite association is represented by gabbro-norites, enderbites, monzodiorites, sub-alkali quartz monzodiorites, quartz monzonites and syenites. Generally, based on their chemical composition, for these rocks typical are large variations in SiO2 composition, calc-alkali and sub-alkali content of alkali amount, low content of periclase with large content of total iron and thus large iron content in rocks. Even if judge only by chemical composition, we may say that these are not typical magmatic but hybrid rocks formed by means of incomplete palingenesis of substratum.

Ingulsky block (Kirovogradsky orogen). Therein developed are Kirovogradsky complex of quartz diorites and tonalites, ultramafite-mafite and monzonite rocks of Korsun-Novomirgorod complex, dyke complex of picrites and camptonites. As concerns association reviewed in direction from ultrabasic rocks to monzonites, we recorded increase in SiO2 in the range of 35‑55 %, increase in the amount of alkalis from 1.2 to 6.6 % with constant preponderance of Na2O compared with K2O and with practically constant total iron content (70‑88 %). In this row the content of TiO2 decreases from 5‑6 % in harzburgites to 0.8‑1.7 % in anorthosites and monzonites. Base rocks are characterized by the highest total iron content in comparison with similar rocks of Korosten Pluton, large content of TiO2 and increased for this type of rocks content of K2O.

Comparison of dyke rocks with ultrabasic rocks of Korsun-Novomirgorod massif shows that with almost one and the same content of SiO2 ultrabasic rocks contain more total iron content than picrites and camptonites. MgO content in picrites is higher with almost one and the same content in camptonites. By content of Na2O and K2O picrites differ from ultrabasic rocks by lower values, while camptonites have approximately comparable content of alkalis. Both picrites and camptonites have lower total iron content in comparison with harzburgites and troctolites of Korsun-Novomirgorod complex.

GSZ. Ultramafite-mafites of kapitansko-derenyukhinsky complex are represented by peridotites, harzburgites, lherzolites, pyroxenites and gabbro. These rocks differ from similar ultramafites of Korsun-Novomirgorod massif by almost twice as large content of MgO and by lower content of alkalis and TiO2.

In the diagram SiO2 – (K2O + Na2O) all magmatic formations of the central part of Ukrainian Shield by their petrochemical composition are within the arrays of sub-alkali and calc-alkali rock series, the latter are typically near sub-alkali series‑calc-alkali series demarcation line. The exception is ultrabasic rocks of kapitansko-derenyukhinsky complex of GSZ which belong to calc-alkali series and represent derivatives of tholeitic magma.

West part of Ukrainian Shield

NKSZ. Therein represented are associations of mafite-ultramafite rocks of Bukinsky complex with crust rocks of middle and acid composition; anorthosites, gabbronorites and leucocratic varieties of Korosten Pluton granites; granites of Uman and Zhitomir complexes and also gabbro-dolerites of Zvizdal-Zalesskaya dyke.

Composition arrays for basite-monzonitoid rocks of Bukinsky massif, gabbro-anortosite-rappakivi rocks of Korosten and Korsun-Novomirgorod Plutons in the diagram A-F-M differ from the arrays that characterize composition of rocks of Skaergaard Intrusion and trapps of Siberian platform. Here rocks have higher sub-alkali composition and higher iron content (in the diagram arrays are shifted to the left from angle M (МgO) and from the line of differentiation of compared rocks).

Gabbro-dolerites of Zvizdal-Zalesskaya dyke have increased content of titanium (ТiO2 up to 3 %), phosphorus (Р2О5 = 0.4-0.6 %) and alkalis (Na2О = 3.1-3.8 %; К2О = 1.1-1.9 %). In the diagram SiO2-(Na2O+K2O) they are in the array of alkali basalts. Rocks have higher iron content (80-90 %) in comparison with basites of Korosten Pluton.

Uman complex. By proportion of SiO2-(Na2O+K2O) granitoids of this complex are distributed into three arrays. The first array is formed by normal equigranular and porphyraceous granites with 67.24‑73.48 % of SiO2 and total content of Na2O+K2O (6.76‑9.60 %); porphyraceous granites are the lowest in this array with somewhat increased content of alkalis. The second array is formed mainly by aplite-pegmatoid granites and also by varieties of equigranular and porphyraceous granites which have the highest content of SiO2 (75.50‑77.09 %). Sub-alkali granites containing up to 11.87 % of Na2O+K2O, where K content is three and more times as large as Na content, form the third array.

Zhitomir complex. According to the results of chemical analysis of granites, groups of normal and leucocratic varieties are identified. SiO2 content in normal varieties is 71.32‑73.0 % and 74.51‑75.02 % in leucocratic varieties. These are sub-alkali rocks containing 7.5‑8.7 % of Na2O+K2O with preponderance of К2O (4.4‑5.4 %) compared with Na2O (3-4 %). Total iron content is 60-80 % and low content (0.1-0.7 %) of MgO.

Granites of Korosten Pluton are basically represented by leucocratic varieties with 73‑75 % of SiO2. These are sub-alkali rocks which contain 8.5‑10 % of Na2O+K2O with preponderance of К2O (5‑7 %) compared with Na2O
(3-4 %). Total iron content is 60-80 % and
low content (0.1-0.4 %) of MgO. In the diagram SiO2 – (Na2O+ K2O) granitoids rocks are in the array of sub-alkali leukogranites. Amid monzonitoid associations we can identify both sub-alkali and calc-alkali associations that may speak for their hybrid origin.

According to Sheremet et al.( 2011) detection of suture zones in Precambrian of Ukrainian Shield assumes existence in this region of magmatic rocks which would conform to those or would be close to those typical for the Phanerozoic island arc system (Zavarnitsky-Benioff zones). Connected with such geodynamic settings in Phanerozoic are andesites, low-titanium basalts of island arcs, absorakites, shoshonites, latites, trachytes and some leucitic (lamproites, leucites) or leucite-containing rocks.

We think that similar differences for magmatic rocks had to be also in Precambrian, although, perfect analogy of geodynamic settings in Phanerozoic and Precambrian can not be expected. However, analysis of petrochemical and geochemical features of single-type Precambrian magmatic rocks of Ukrainian Shield enables us to identify their essential differences, which can be explained by different geodynamic settings of their formation in conditions of rifting crustal shortening.

In our case the most interesting is the type of rocks formed in conditions of crustal shortening, which presumably are connected with formation of suture (subduction) zones of Ukrainian Shield.

Outstanding feature of gabbro of these zones is their low titanium content peculiar to basites (volcanites) of shortening zones. More over, they have rather low content of ore minerals (magnetite and ilmenite). The gabbros are highly amphibolized, and their amphibolization can be explained by watering of basalt melts in subduction zones. Low titanium content of gabbro as well as their high amphibolization differ them from basites and mafites of Korosten and Korsun-Novomirgorod Plutons had been forming in conditions of crustal shortening.



Classification and Nomenclature of Magmatic Rocks. (Handbook). / O. A. Bogatikov, V. I. Gonyshakova, S. V. Efremov et al. – Moscow: Nedra, 1981. 159 p.

Sheremet E. M., Kulik S. N., Krivdik S. G. et al.; Geologic-Geophysical Criteria of Ore Content and Metallogeny of Subduction Zones of Ukrainian Shield / under the editorship of A. V. Antsiferov. UkrNIMI. Donetsk: Knowledge (Donetsk Branch), 2011. 285 p.