Project

Discipline

Tectono-magmatic setting; Ore deposits; Lesser Caucasus; Magmatic rocks; Tectonics; Geodynamics; Tethys belt; Porphyry Cu-Mo deposits; Epithermal deposits

Lead
Métallogénie du Petit-Caucase: depuis la construction d’un arc magmatique à une évolution post-collisionIntroduction Le contexte géodynamique et métallogénique du Petit-Caucase reste peu connu. Toutes les étapes de l’évolution d’une chaîne de montagne sont conservées, depuis la formation d’un arc magmatique aux étapes de destruction d’une chaîne de montagne, et peuvent être étudiées de manière indépendante, y compris les différents types de gisements métallifères du Jurassique au Cénozoïque.
Lay summary
Contenu et objectifs  Trois thèmes principaux seront abordés: (i) l’évolution magmatique, tectonique et métallogénique cénozoïque de l’extrême sud du Petit-Caucase, (ii) la distinction des contextes tectoniques de subduction éocène et post-collision néogène des districts minéralisés le long de la zone de collision entre l’Eurasie et des microplaques d’origine gondwanienne, et (iii) la compréhension l’ensemble de l’évolution métallogénique et géodynamique du Jurassique au Cénozoïque le long de deux traverses représentatives au travers du Petit-Caucase.   Contexte scientifique et social La recherche présentée dans ce projet de recherche permettra de contribuer à différents domaines, y compris tectonique, magmatisme, géochronologie, évolution de la croûte terrestre et formation de gisements métallifères. Ce projet permettra de mieux comprendre le lien géodynamique et métallogénique du Petit-Caucase avec les Anatolides et les chaînes iraniennes. Cette étude permettra de développer des notions utiles aux compagnies d’exploration minière pour découvrir de nouvelles ressources naturelles nécessaires au développement durable de notre société.   Mots-clé Gisements métallifères, géodynamique, roches magmatiques, Petit-Caucase, Téthys, tectonique, porphyres Cu-Mo, épithermaux

Direct link to Lay Summary

Last update: 03.10.2016

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Number	Title	Start	Funding scheme

In this project, we focus on the Lesser Caucasus, which extends from the Black Sea to the Caspian Sea. The Lesser Caucasus is the final product of a complex geodynamic and metallogenic evolution, lasting from Jurassic subduction of a northern branch of the Neotethys beneath Eurasia to final Neogene Arabia-Eurasia collision. This mountain belt is a hyphen, which links the Tethyan segments of Iran with the ones of Anatolia and Europe. Despite its pivotal location, the geodynamic, tectonic, magmatic and metallogenic knowledge of the Lesser Caucasus is lagging behind the comprehensive knowledge available for the geodynamic and metallogenic evolution of southeastern Europe, Anatolia and Iran. Our studies will contribute to filling this gap of knowledge.The Lesser Caucasus stands out as a unique segment of the Tethyan belt, because it has the particularity of featuring both well-preserved subduction and continental collision to post-collision stages in a relatively short and narrow crustal segment. This belt is invaluable for deciphering the role of structures previously acquired in the subduction stage, and that of the collisional ones, which controlled the numerous and successive ore-forming and magmatic events, which affected this region. This unique environment is unlike other portions of the Alpine-Himalayan orogenic belt, because in our study area the Arabia-Eurasia collision was accommodated essentially in the Greater Caucasus and along the North Anatolian Fault, preserving the independent evolutionary stages of the Lesser Caucasus.Ore formation along the Lesser Caucasus can be assigned to two different evolution stages: (1) Mesozoic arc construction and evolution along the Eurasian margin, and (2) Cenozoic magmatism and tectonics controlled by structures inherited from Late Cretaceous-Paleogene accretion boundaries along the Eurasian margin. In order to clarify the geodynamic and metallogenic evolution of the Lesser Caucasus this investigation has been subdivided into three subprojects. Subproject A will last only for three months and will allow our current Ph.D. student to finalise his thesis manuscript on his research on the temporal and genetic link between incremental pluton assembly and pulsed porphyry Cu-Mo formation in an accretionary orogeny, focused on the southernmost Lesser Caucasus. Subproject B will last three years, and one new Ph.D. student will be supported by this project, and will collaborate with a post-doctoral fellow already working on Cenozoic epithermal and porphyry deposits of the Lesser Caucasus to understand the role of subduction and collision/post-collision tectonics and magmatism during their genesis. Support for two years is requested for one post-doctoral fellow to work on subproject C, which will allow us to provide an integrated model for the Jurassic to Cenozoic metallogenic evolution of the Lesser Caucasus. This subproject is designed to investigate the link among ore bodies, tectonic elements, and magmatic rocks along two representative transects across the Lesser Caucasus.The investigations described in this grant proposal are relevant to a large palette of disciplines in geosciences. This comprehensive study integrates tectonic aspects, magmatism, high-precision geochronology and ore formation in order to provide an integrated geodynamic and metallogenic model for the Lesser Caucasus. This project will allow us to identify key processes (tectonic setting, fertile vs. barren magmatism, timing-contemporaneity of events) that operate during short, pulsed ore deposit forming events in an otherwise long, mostly barren geodynamic evolution of mountain belts. Such knowledge is useful to develop predictive tools for mineral exploration, and ensure the sustainable supply of mineral resources.