Mixed siliciclastic-carbonate margins record complex interactions between climate, sea-level change, sedimentary, hydrodynamic and biogenic processes. Understanding mixed margin evolution is a critical need, as coastal and shelf environments are highly vulnerable to environmental stressors including extreme events, climate change, and anthropogenic influence. Sediment- and hydrodynamics within these systems are governed by complex feedbacks and external controls, yet remain poorly understood. This session explores how the co-existence and interplay of carbonate and siliciclastic systems shape coastal and shelf environments under changing climatic and environmental conditions. We welcome research addressing system interactions, the role of anthropogenic stressors, and implications for ecosystems, hazard mitigation, coastal resilience, and sustainable resource use. The aim is to advance a holistic understanding of mixed margins through case studies, experimental and numerical approaches.