His memoir on this animal places him among the forerunners of, if not within the ranks of, the founders of palaeontology.
Meanwhile Soldani, an Italian, had, in 1780, shown that the limestone strata of Italy had accumulated in a deep sea, at least far from land, and he was the first to observe the alternation of marine and fresh-water strata in the Paris basin.
Lamarck must have taken much interest in the famous controversy between the Vulcanists and Neptunists.

He visited Freyburg in 1771; whether he met Werner is not known, as Werner began to lecture in 1775.

He must have personally known Faujas of Paris, who, in 1779, published his description of the volcanoes of Vivarais and Velay; while Desmarest's (1725-1815) elaborate work on the volcanoes of Auvergne, published in 1774, in which he proved the igneous origin of basalt, was the best piece of geological exploration which had yet been accomplished, and is still a classic.[71] Werner (1750-1817), the propounder of the Neptunian theory, was one of the founders of modern geology and of palaeontology.

His work entitled _Ueber die auessern Kennzeichen der Fossilien_ appeared in 1774; his _Kurze Klassifikation und Beschreibung der Gebirgsarten_ in 1787.

He discovered the law of the superposition of stratified rocks, though he wrongly considered volcanic rocks, such as basalt, to be of aqueous origin, being as he supposed formed of chemical precipitates from water.
But he was the first to state that the age of different formations can be told by their fossils, certain species being confined to particular beds, while others ranged throughout whole formations, and others seemed to occur in several different formations; "the original species found in these formations appearing to have been so constituted as to live through a variety of changes which had destroyed hundreds of other species which we find confined to particular beds."[72] His views as regards fossils, as Jameson states, were probably not known to Cuvier, and it is more than doubtful whether Lamarck knew of them.