MAGMATIC EVOLUTION OF THE JURASSIC JORKVALI INTRUSION (CAUCASUS): PETROGRAPHIC, GEOCHEMICAL, AND GEODYNAMIC DATA

D. Shengelia; T. Tsutsunava; G. Chichinadze; G. Beridze; I. Javakhishvili; N. Maisuradze; R. Vekua

doi:10.52340/pajig.2026.137.05

Authors

D. Shengelia Alexandre Janelidze Institute of Geology of Ivane Javakhishvili Tbilisi State University https://orcid.org/0000-0003-3598-0734
T. Tsutsunava Alexandre Janelidze Institute of Geology of Ivane Javakhishvili Tbilisi State University https://orcid.org/0000-0002-3546-3588
G. Chichinadze Alexandre Janelidze Institute of Geology of Ivane Javakhishvili Tbilisi State University https://orcid.org/0000-0003-4778-5223
G. Beridze Alexandre Janelidze Institute of Geology of Ivane Javakhishvili Tbilisi State University https://orcid.org/0000-0002-9573-8600
I. Javakhishvili Alexandre Janelidze Institute of Geology of Ivane Javakhishvili Tbilisi State University https://orcid.org/0000-0002-3250-3687
N. Maisuradze Alexandre Janelidze Institute of Geology of Ivane Javakhishvili Tbilisi State University https://orcid.org/0009-0001-7478-6646
R. Vekua Alexandre Janelidze Institute of Geology of Ivane Javakhishvili Tbilisi State University https://orcid.org/0009-0005-7801-9961

DOI:

https://doi.org/10.52340/pajig.2026.137.05

Keywords:

petrography, Jorkvali Intrusion, geochemistry, Jurassic supra-subduction magmatism, petrography, geochemistry

Abstract

The Jorkvali Intrusion represents a Jurassic intrusive body within the fold system of the Southern Slope of the Greater Caucasus. The intrusion consists predominantly of gabbro-pyroxenites, accompanied by diorite-porphyrite veins and minor dike-like bodies. This study integrates field observations, petrographic data, and whole-rock geochemical analyses to characterize the composition and magmatic evolution of the intrusion and to constrain its geodynamic setting. Geochemical data indicate that the rocks represent a progressively differentiated magmatic series, ranging from mantle-derived mafic–ultramafic magmas to more differentiated calc-alkaline and high-K compositions. Discrimination diagrams indicate a subduction-related geodynamic environment, while the geochemical characteristics of the mafic rocks suggest significant mantle depletion and interaction with subduction-related fluids. The combined petrographic and geochemical evidence suggests that the Jorkvali Intrusion formed within a Middle Jurassic supra-subduction magmatic system in the Caucasus region.

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