The Great Devonian Controversy began in 1834 when Roderick Murchison disagreed with Henry De la Beche as to the dating of certain petrified plants found in coals in the Greywacke stratum in North

Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devo ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe ...

. De La Beche was claiming that since

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carboniferou ...

fossils were found deep in the Greywacke stratum, which itself was older than the

period, this method of dating rocks was not valid. Murchison, in contrast, claimed that De La Beche had not placed the fossils correctly, as they were occurring quite near the top of the stratum as opposed to deep within it. De La Beche soon agreed with Murchison's argument as to the placing of fossils but maintained that since a layer of Old Red Sandstone, present in other formations, was missing between the layer of older rock and this new formation, there was still insufficient evidence to suggest the formation was not part of the older Silurian strata. There followed much debate and some extensive investigations which ranged as far as Russia, where in 1840 Murchison discovered a layer similar to the one found in Devon placed between well-defined Silurian and Carboniferous deposits. This discovery put an end to the controversy and led to the definition of a new period called

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, wh ...

Further reading