The marble on a floor was once lime mud on a seabed, buried deep and cooked under pressure until it recrystallised. No rock stays in one form forever: igneous, sedimentary and metamorphic are three stations on a single loop of matter, and their proportions shift over time depending on which leg runs hardest. Subduction makes more igneous rock, deep burial makes metamorphic rock, and contact metamorphism skips the sedimentary leg entirely, cooking the rock in place beside a hot intrusion.
The marble on a floor was once lime mud on a seabed, buried deep and cooked under pressure until it recrystallised. No rock stays in one form forever: igneous, sedimentary and metamorphic are three stations on a single loop of matter, and their proportions shift over time depending on which leg runs hardest. Subduction makes more igneous rock, deep burial makes metamorphic rock, and contact metamorphism skips the sedimentary leg entirely, cooking the rock in place beside a hot intrusion.
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