With a little help from friends: Pierre-Louis-Antoine Cordier (1777–1861): 50 years of experimental work on basalt

Experimentation was more prevalent and more influential in the early days of geology than has generally been recognized. While historical narratives often associate very few names with geoscientific insights or advances, these advances are often the result of general movement within the whole fabric of geology and mineralogy. This applies to the question of basalt origin, which was more complex that it appears superficially. Ancient basalts from extinct volcanoes with no observed centers were often altered on the surface, and differed from more recent flows. The tools of microscopy and the blowpipe were used with increasing advantage by inquirers from Boccone to Cordier. Combining the methods of his predecessors and contemporaries, Cordier was able to demonstrate convincingly that similar rocks were due to similar causes whatever their ages. A more complete history results from looking at the “hero” in the broader spectrum of the resources available to him.