Explore the complex dynamics of deep crustal metamorphic carbon cycling in collisional orogens through this comprehensive Daly Lecture. Delve into the poorly understood aspects of the global carbon cycle, examining the debate surrounding fluid fluxes during collisional orogenesis. Investigate various CO2 release processes, including internally-buffered reactions, fluid infiltration, carbonate mineral dissolution, and graphite oxidation. Analyze field-based results showing significant CO2 loss during metamorphism and its potential impact on global atmospheric temperatures. Examine models of coupled flow and retrograde carbonation reactions, considering both Darcian and two-phase fluid flow. Discuss the CO2 sequestration potential of various rock types and the challenges in understanding retrograde reactions. Cover topics such as global carbonate rocks, metamorphic environments, zoned metacarbonate layers, mountain belt areas, flux comparisons, graphitic organic matter, fluid flow down temperature gradients, retrograde channelization, porosity waves, and the retrograde breakdown of tremolite. Read more