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Werner (1750-1817) elaborated Lehmann's scheme and modified it. He was the great teacher of geology at Freiburg, Germany, in 1815, and left his impress upon the geologists of the time, though he wrote little in the way of systematic exposition of his theories of classification. He adopted Lehmann's Primitiv Gebirge, but of the Secondary rocks he made a lower class, which he called transition rocks (Uebergangsgebirge), which were stratified, contained none or but few fossils, and were more or less oblique in position; these characteristics were observed in northern Europe, where he studied them. The remainder of the original Secondary rocks, he called Floetzgebirge, or flat-lying formations, and these were the equivalents of Lehmann's Secondary in the classification of the early part of the century. Late, the Wernerian school called the formations above the Cretaceous neues Floetzgebirge, to which, as they were studied in the Paris basin, Cuvier and Brongniart, in the latter decade of the last century, applied the name Tertiary, which still remains in the scheme. Werner called the looser, overlying, unconsolidated rocks angeschwempt Gebirge, or alluvial formations, which were afterwards, as above stated, called Quaternary by Morlot.

The classification of Lehmann, as perfected by Werner, was then as follows:

These were the formations which made up the geological series as then recognized. Volcanic rocks were looked upon as local formations, and of small account in general classification. But they came to be more deeply studied by Werner, and his notion that trap was of aqueous origin led to much controversy, and gave chief prominence to his views (the Neptunian theory) and to that classification of rocks which will be next considered.