Multiple intrusion stages and mantle sources of the Paleozoic Kuznetsk Alatau alkaline province, Southern Siberia: geochemistry and Permian U–Pb, Sm–Nd ages in the Goryachegorsk ijolite-foyaite intrusion

The Paleozoic-Aged University Foidolite-Gabbro Pluton of the Northeastern Part of the Kuznetsk Alatau Ridge, Siberia: Geochemical Characterization, Geochronology, Petrography and Geophysical Indication of Potential High-Grade Nepheline Ore

“…At the Kiya-Shaltyrskii deposit [21], urtite bodies are also an independent and later phase. Separated from gabbroids, basic foidolites are represented as separate bodies within the Goryachegorskii pluton (both gradual transitions and intrusive relationships between plagioclase ijolites and feldspar urtites are observed here) [31].…”

“…Subalkaline, alkaline rocks of the University pluton had common values of primary isotopes of neodymium 143 Nd/ 144 Nd(t) = 0.512223-0.512358 and εNd(T) ranging from +3.2 to +8.7 and, possibly, originated from the moderately depleted mantle type (PREMA) with crustal enrichment of the primary strontium isotope ratio 87 Sr/ 86 Sr(t) = 0.704834-0.706037 and εSr(T) from +12.93 to 28.31 (Figure 9, Table 1). Enrichment in radiogenic 87 Sr was found for many Paleozoic-Mesozoic alkaline and carbonatite complexes in the northern part of the Kuznetsk Alatau, Southeastern Tuva, and the southeastern part of the Russian Altai [31]. The ages of the University pluton and associated N-S dike swarm were determined by Sm-Nd dating of minerals and whole compositions.…”

“…Consequently, it will be possible to compare the magmatic events that took place at the University pluton with the events of other alkaline-basic intrusions KA, which will help to reveal the conditions of the formation of the University pluton. Accordingly, as a result of the data from isotope-geochronological studies (Sm-Nd, Rb-Sr, U-Pb and Ar-Ar), alkaline intrusions can be divided into three age groups, corresponding to the Cambrian and Early Ordovician (510-480 Ma), Early and Middle Devonian (410-390 Ma) and Late Permian (265 Ma) [8][9][10][11][12]18,21,27,28,[31][32][33]45,46,48,72].…”

Evolution of Syenite Magmas: Insights from the Geology, Geochemistry and O-Nd Isotopic Characteristics of the Ordovician Saibar Intrusion, Altai-Sayan Area, Russia

“…Within the Saibar intrusion, there are no mafic rocks with a SiO2 content of 52 wt.% that preceded or accompanied the formation of syenites. This limits the po of reconstructing the composition of magmas that was parental for the syenitic r the same time, the other syenite-bearing intrusions of the Altai-Sayan fold belt mafic rocks formed synchronously with examined syenites, which indicates the spondence to the composition of parent magmas [32][33][34][35][36][37][38][39][40][41][42][43][44][45]. Accordingly, the geolo finity of the Saibar intrusion to other similar intrusions suggests a genetic conne tween its rocks and the mafic magmas, which occurred at levels of the magmati inaccessible to observation.…”

“…This part of the CAOB covers the sizable Altay-Sayan fold belt, where alkaline magmatism produced the syenites typical of Kuznetsk Alatau and southeast of Tuva in the Eastern Sayan Mountains and Sangilen Highland, as well as in the Minusinsk Trough subdividing these territories. Alkaline magmatism proceeded several times throughout the Paleozoic epoch in the Early Paleozoic (510-450 Ma), Devonian (410-390 Ma), and Late Carboniferous and Early Permian (305-280 Ma) [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. [47,48].…”