Making Adakites in continental subduction 

University of Bucharest

Project code: PN-IV-P1-PCE-2023-0204

Director: Mihai Ducea

Title: ADAKITE PRODUCTION IN CONTINENTAL SUBDUCTION ZONES

Project runs from Jan 2025 to December 2027

Project Summary

This project investigates how unusual, silica-rich magmas known as adakites form during continental collision - one of the most dynamic and least understood stages of Earth’s tectonic cycle. Focusing on key volcanic regions of Romania (the Southern Harghita and Southern Apuseni Mountains), the project addresses a fundamental question in igneous petrology: can adakite-like magmas be generated by partial melting of subducted continental crust, and how are their compositions modified as they ascend through the mantle and crust?

Adakites are traditionally linked to melting of subducted oceanic slabs, yet many adakitic rocks occur in continental collision zones where oceanic subduction is absent or waning. This apparent paradox makes the Carpathian - Apuseni region an exceptional natural laboratory. Here, felsic adakitic and shoshonitic magmas coexist with more mafic magmas, and field evidence suggests interaction between chemically distinct melt components during magma ascent and storage.

The project combines thermodynamic phase equilibria modelling with state-of-the-art mineral-scale geochemical, isotopic, and geochronological analyses to test two competing end-member models for adakite formation. One hypothesis proposes that felsic melts are produced by partial melting of a subducted continental slab and subsequently react with, or mix within, the mantle. The alternative hypothesis links adakitic signatures to melting, assimilation, storage, and homogenization (MASH) processes at the crust–mantle boundary. By analysing individual minerals, melt inclusions, and zircons (each recording different stages of magma evolution) the project seeks to determine the origin, timing, and interaction of felsic and mafic components in these magmatic systems.

Numerical modelling will define the pressure - temperature conditions and source compositions capable of producing adakite-like melts, while detailed chemical and isotopic “fingerprinting” of crystals will reveal whether magmas evolved in closed systems or were repeatedly modified by open-system processes such as mixing and reactive transport. Zircon petrochronology will further constrain magma sources and pathways, distinguishing locally derived crustal material from deeply subducted continental components.

By integrating modelling, field geology, and high-resolution analytical data, this project aims to clarify how continental collision reshapes the lower crust and mantle, how felsic magmas are generated in such settings, and why adakitic signatures persist during magma ascent. The results will have broad implications for understanding collision-related magmatism, crustal growth, and the geodynamic evolution of the Carpathian region and similar orogenic belts worldwide.

Expected Cognitive and Socio-Economic Impact

Cognitive / Scientific Impact

• Advances fundamental understanding of magma generation in continental collision zones, addressing a long-standing scientific problem in Earth sciences.

• Provides a coherent, transferable model for syn-collisional adakitic magmatism, with relevance beyond Romania to similar geological settings worldwide.

• Delivers high-quality scientific outputs (minimum four open-access papers in Q1 international journals), increasing the visibility and competitiveness of Romanian geoscience research within the European Research Area.

• Strengthens Romania’s contribution to international research networks in petrology, geochemistry, and geodynamics.

Socio-Economic and Human Capital Impact

• Trains a new generation of highly skilled researchers (PhD and MSc students, early-career scientists) in advanced analytical techniques and quantitative modelling, aligned with EU priorities for knowledge-based economies.

• Enhances national research capacity and long-term expertise in strategically important scientific domains.

• Promotes knowledge transfer through international conferences, academic seminars, and open-access dissemination, ensuring efficient circulation of results to both specialist and non-specialist audiences.

• Supports science education and public engagement through outreach activities targeting students and the general public, encouraging interest in STEM careers and increasing awareness of Romania’s geological heritage.

Long-Term Impact

• Contributes to the sustainability and international competitiveness of Romanian Earth science research.

• Establishes a strong foundation for future national and European research projects, fostering integration into EU-funded research programmes.