Chapter XXXV

—ON THE DIFFERENT AGES OF THE METAMORPHIC ROCKS.

Difficulty of ascertaining the Age of metamorphic Strata. — Metamorphic Strata of Eocene date in the Alps of Switzerland and Savoy. — Limestone and Shale of Carrara. — Metamorphic Strata of older date than the Silurian and Cambrian Rocks. — Order of Succession in metamorphic Rocks. — Uniformity of mineral Character. — Supposed Azoic Period. — Connection between the Absence of Organic Remains and the Scarcity of calcareous Matter in metamorphic Rocks.

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