Neptunism is a discredited and obsolete scientific theory of geology proposed by Johan Gottlob Lehmann and Abraham Werner in the later half of the 18th century.It was named after Neptune, the ancient Roman name for the ancient Greek god of the sea, Poseidon. It has proposed that the surface feature of Earth (mountains, plains, oceans, etc.) were formed by a great flood that completely encircled a "nucleus" of primordial matter. As this great flood receded, rock strata were formed from materials present in the flood waters. All surface features of the Earth were assigned to the agency of this one momentous geological event. Since the time of the great flood, it was thought that there had been ilttle change in the Earth. This theory gained wide acceptance for several reasons. It was consistence with the body of observational data in geology. Approximately seventy-five percent of all the rock ot the Earth's surface have been formed from water-lain sedimentsthat have been converted into solid (sedimentary) rocks. Furthermore, this theory was easily accepted by the Churchm as the great flood was vaguely reminiscent of the Noachian Flood described by the Bible. and it could be interpreted as representing the single "act of creation" described in the Book of Genesis. The formation of igneous rocks represented an exception to Neptunist theory. Igneous rocks are formed by volcanic activity and were considered to be younger than sedimentary rocks. However, the younger age of igneous rocks did not present a serious exception to Neptunist theory. Note that vulcanism was thought to resuly from the spontaneous combustion of coal deposits withing the Earth and was considered a minor event in the generally static, unchangin history of the Earth's surface. An obsolete scientific theory is a scientific theory that was once commonly accepted but (for whatever reason) is no longer considered the most complete description of reality by mainstream science; or a falsifiable theory which has been shown to be false. ... This article includes a list of works cited but its sources remain unclear because it lacks in-text citations. ... Abraham Gottlob Werner Abraham Gottlob Werner (1749 or 1750 - 1817), was born in Wehrau, a city in Prussian Silesia, southeastern Germany. ... (17th century - 18th century - 19th century - more centuries) As a means of recording the passage of time, the 18th century refers to the century that lasted from 1701 through 1800. ... Neptune reigns in the city of Bristol. ... Ancient Rome was a civilization that grew from a small agricultural community founded on the Italian Peninsula circa the 9th century BC to a massive empire straddling the Mediterranean Sea. ... The Temple to Athena, the Parthenon Ancient Greece is a period in Greek history that lasted for around three thousand years. ...

 Neptunism lost mainstream scientific support in the early 19th century as the principle of uniformitarianism was shown to fit better with the geological facts as they became better known. Plutonism then replaced Neptunism. In modern geology, many different forms of rock formation are acknowledged, and the formation of sedimentary rock occurs through processes very similar to those described by Neptunism. 

The French naturalist Georges de Buffon championed this idea and concluded that the center of volcanic activity was not deep in the bowels of earth but near the surface, where it was exposed to wind and rain. Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... Uniformitarianism, in the philosophy of science, is the assumption that the natural processes operating in the past are the same as those that can be observed operating in the present. ... Plutonism was a theory of Geology around the turn of the 19th Century that claimed that volcanic activity was the source of rocks on the surface of the Earth. ... This article or section does not cite any references or sources. ... Georges-Louis Leclerc, Comte de Buffon, by François-Hubert Drouais (1727-1775). ...

The theory, and its intellectual context, are treated with engaging irony in Daniel Kehlmann's fictionalised account of the travels of Alexander von Humboldt, Measuring the World (2006). An 1859 portrait of Alexander von Humboldt by the artist Julius Schrader, showing Mount Chimborazo in the background. ... Measuring the World in 8 different languages Measuring the World was written in German by Daniel Kehlmann as Die Vermessung der Welt. ...

References

• Erickson, Jon, Plate Tectonics, New York: Facts On File, 1992