Dear list members, We would like to invite you to submit an abstract to the Goldschmidt session on carbonatites (05d) in Montréal (July 12-17, 2026). *05d - Carbonatite and alkaline/peralkaline magmatic and hydrothermal activity: Windows into mantle/crustal processes and implications for critical metal resources”*  Keynote speaker: Gregory Yaxley (ANU) Invited speakers:            Max Schmidt (ETH, Zurich) Anthony Williams-Jones (McGill University)             Kathryn E. Watts (USGS)             **Theme:** 05: Energy, resources, and the environment    **Description of the special session (05d):** Carbonatites and alkaline/peralkaline igneous rocks represent rare but key manifestations of mantle and crustal processes typically associated with intracratonic anorogenic and postcollisional settings. Their occurrence provides crucial insights into mantle/crustal source heterogeneity, the role of volatiles in magma and deposit genesis, and the links between lithospheric architecture and magmatic activity. Beyond their petrological significance, these systems are also of considerable economic importance, as they host world-class deposits of critical raw materials, such as rare earth elements, niobium, phosphorus, zirconium, and fluorine. Understanding the genesis, evolution, emplacement, and metallogeny of carbonatites and alkaline/peralkaline igneous rocks therefore has implications that extend from mantle geodynamics to resource sustainability. This session invites contributions that explore the wide spectrum of research related to carbonatite and alkaline/peralkaline magmatism and their implication for the formation of mineral deposits. We welcome studies on mantle and crustal sources, formation processes, and the role of fluids and metasomatism in generating a wide variety of rock units and deposits. Contributions focusing on field relationships, mineralogy, geochronology, isotope and trace element geochemistry, experimental petrology, and numerical modelling are encouraged, as well as studies highlighting ore-forming processes and the distribution of critical metals. By bringing together diverse lines of evidence, this session aims to stimulate discussion on the petrogenesis, evolution, alteration, and economic potential of these unique and diverse magmatic systems. You can find information about the session at: <https://conf.goldschmidt.info/goldschmidt/2026/meetingapp.cgi/Session/8564>