Plutonism
A main reason Pluto was incorporated into the classification was due to the plutonic rocks commonly being present in gold and silver ore deposits (veins).
[5] The idea contested Abraham Werner's neptunist theory which proposed that the Earth had formed from a mass of water and suspended material which had formed rocks as layers of deposited sediment which became the continents when the water retreated, further layers being deposited by floods and some volcanic activity.
[5] Plutonists strongly disputed the neptunist view that rocks had formed by processes that no longer operated, instead supporting Hutton's theory.
The arguments continued into the early 19th century, and eventually the plutonist views on the origin of rocks prevailed in the wake of the work of Charles Lyell in the 1830s, who incorporated this theory into uniformitarianism.
[5] One of the first notable scientists to propose an early theory of plutonism was Abbé Anton Moro, who in the first half of the 18th century was able to inform the scientific community how to differentiate between volcanic and sedimentary rocks.
[4] This suggested to him that at one point in the past, through the force of volcanic fire, islands and continents rose from the bottom of the sea.
[4] In the 1780s, Hutton started opposing the neptunist view of previous catastrophic events being the cause of the current landscape, with no modern equivalency.
[11] He used the Glen Tilt of Perthshire as evidence to support his argument, where the used location was used as an example of the neptunist theory prior to his hypothesis of the granite present there.
[5] The theory included aspects of plutonism as core concepts resulting in the de facto general acceptance of plutonism, as uniformitarianism became widely accepted within the scientific community, resulting in Hutton becoming the “Father of Geology”, due to the presence of Hutton's work as core concepts.
[5][11] As mentioned prior, there were two prevailing theories during the 18th century to explain the current arrangement of the landscape and rock formations: plutonism and neptunism.
[5] Hutton believed that the granites were injected within the Glen Tilt of Perthshire as they were intruded through Dalradian metasediments, indicated by the cut across sediment layers.
[5] In 1773, prior to Hutton’s observations, Abraham Gottlob Werner published his mineralogy book On the External Characteristics of Fossils, which categorised minerals through their physical characteristics alone, which allowed him to obtain the position of Curator of Freiburg School of Mining’s mineral collection and teacher of mining, where he was able to promote his theory of neptunism.
[5] This development was noticeable in the work of Alexander von Humboldt (1769–1859), who had studied with Werner in Freiberg and gradually departed from his teacher's theories.
[5] However, the schism ended through Lyell's book Principles of Geology published in 1830, resulting in the formation of uniformitarianism, which incorporated Hutton's ideas of plutonism.
