SMITH'S MAPPING IN CONTEXT OF HISTORY OF GEOLOGY

William Smith is the author of the most celebrated geological map in the world and deservedly so. Smith's contacts can be followed on a modern map of England and speak for their author's remarkable talents of observation and his intuition of what is important in geology. Smith was a practical man and his chief purpose was to be able to follow strata at depth to see which may be encountered during construction work. The great success and exquisite beauty of his map quicky gave rise to legends that are important to dispel if we are to understand the essence of geological mapping. No geological map is an objective reflexion of what is on the ground. It represents its author's choice which is dependent on his knowledge and purpose. Smith's map is often represented as the first geological map of a country. It was not: Guettard and Lavoisier's Atlas of France predated his work by more than half a century. Smith is credited with recognising the importance of fossils for identifying strata for the first time. He did nothing of the sort. That credit goes to Georges Cuvier alone (and not to Cuvier and Brongniart together). Smith was after identifying strata and he found in the inclusions within a stratum (fossils, minerals, ocre etc.) what he thought to be reliable guides. Guettard and Lavoisier were interested in tracing rocks and included minerals. Thus their map was a 'mineral map' of France. Cuvier was interested in documenting the succession of life. He thus became the single father of biostratigraphy (notwithstanding the earlier suggestions by Buffon and Soulavie). However, the map by Cuvier and Brongniart of the Paris basin is still a lithostratigraphic map supported by vertebrate fossils included in the strata. However, Cuvier was aware of the power of his discovery and clearly said so. It is important to understand what each geologist aimed at doing, if we are to understand their accomplishments properly. That would help us understanding our own work today, too.