May 23, 2022

Plutonism is the geological theory proposed by James Hutton at the end of the 18th century, which defined the generation of rocks as a result of volcanic processes. The theory got its name from the Roman god Pluto. Plutonism enjoyed a certain acceptance among the scientific community, discrediting the Neptunism of Abraham Gottlob Werner, who defended the submarine origin of rocks through sedimentation. The supporters of plutonism were scientifically completely opposed to those of Neptunism: They defended the underwater formation of minerals and the concept of a "universal ocean", which they denied; the plutonists, in fact, denied the idea that the water could produce any effect on the mineral. The theory, therefore, was tremendously controversial, mainly because it implicitly denied the concept of the Universal Flood, and therefore the historical validity of the biblical texts. Thus, when in 1788 the Royal Society Transactions of Edinburgh published the theory, James Hutton was accused of atheism.[1] Some authors have pointed out that perhaps it was precisely the opposite: Hutton's theory was based in part on the conviction of a balanced natural order. For Hutton, the process of erosion and destruction of superficial geological material had to be matched by an analogous process of generation of new materials. This process could only occur in the Earth's core at very high temperatures, which were responsible for the elevations of the land, earthworks, etc. But the notable tension between Neptunists and Plutonists had a second confrontational aspect: geological time. Supporters of Neptunism - including scientists of the prestige of Alexander von Humboldt - admitted the historical certainty of the Genesis narrative; and his dating of the world was around 6,000 years. The plutonists, on the contrary, not only denied the historical validity of the deluge but also considered geological processes as a much slower phenomenon. The term geological age was then coined, to define the wide margins of time necessary for any geological phenomenon. This new concept would be known as uniformitarianism, and it was simply based on the fact that the geological processes that had intervened in very remote times were still acting in the present. The perspective of this "aging" of the world was a shocking idea for the society of the time, which could only assimilate it progressively, as the following references indicate: In 1778, Buffon affirms that the Earth is a fragment of the Sun in cooling, its age is 74,000 years; In 1830 Lyell dates the age of the Earth - in a work that influenced Darwin - to a few million years; in the mid-19th century, Lord Kelvin estimated the planet to be about 100 million years old. By the turn of the 20th century this estimate had risen to 1.5 billion years, and by the time Arthur Holmes discovered geological radiation dating, this figure it shot up to 4.5 billion years, which is what is considered in contemporary geology. Both Plutonism and Neptunism are now considered extremist and outdated positions. Contemporary geologists have defined three rock-forming processes: igneous, sedimentary, and metamorphic.


External Links

History of Science: Early Modern Geology. . . And Still We Evolve, A Handbook on the History of Modern Science, Ian Johnston of Malaspina University-College, Nanaimo, BC. (public domain)