The Pierres du Niton (French for ''Neptune's Stones'') are two

glacial erratic A glacial erratic is a glacially deposited rock (geology), rock differing from the type of country rock (geology), rock native to the area in which it rests. Erratics, which take their name from the Latin word ' ("to wander"), are carried by gla ...

s in

Lake Geneva Lake Geneva is a deep lake on the north side of the Alps, shared between Switzerland and France. It is one of the List of largest lakes of Europe, largest lakes in Western Europe and the largest on the course of the Rhône. Sixty percent () ...

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

, in

Geneva Geneva ( , ; ) ; ; . is the List of cities in Switzerland, second-most populous city in Switzerland and the most populous in French-speaking Romandy. Situated in the southwest of the country, where the Rhône exits Lake Geneva, it is the ca ...

harbor. On the left bank of the lake near Quai Gustave-Ador, they are remnants from the last

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and g ...

, left by the Rhone glacier. Because of their role in Swiss cartography, the rocks have been declared a " Geotope", a national site of geological heritage.

Geology

Genevan scientist Horace Bénédict de Saussure identified the rocks as

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

from the Alps in 1779.

Jean-André Deluc Jean-André Deluc or de Luc (8 February 1727 – 7 November 1817) was a geologist, natural philosopher and meteorologist from the Republic of Geneva. He also devised measuring instruments. Biography Jean-André Deluc was born in Geneva. His ...

later described the two rocks as part of a larger group of 24 erratics of similar composition: a granite with large feldspar crystals, slightly violet quartz, and slightly green chlorite. More recent analysis has determined their likely origin in the Mont Blanc massif, being dated to around 303 million years before present. The Repère ("landmark") Pierre du Niton is the name of the rock which is bigger and further from the shore

History

The word ''Niton'' is derived from the ancient water god

Neptune Neptune is the eighth and farthest known planet from the Sun. It is the List of Solar System objects by size, fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 t ...

, who was revered by the

Gauls The Gauls (; , ''Galátai'') were a group of Celts, Celtic peoples of mainland Europe in the Iron Age Europe, Iron Age and the Roman Gaul, Roman period (roughly 5th century BC to 5th century AD). Their homeland was known as Gaul (''Gallia''). Th ...

who settled at the lake, as old inscriptions in Geneva and

Lausanne Lausanne ( , ; ; ) is the capital and largest List of towns in Switzerland, city of the Swiss French-speaking Cantons of Switzerland, canton of Vaud, in Switzerland. It is a hilly city situated on the shores of Lake Geneva, about halfway bet ...

indicate.Répertoire des immeubles et objets classés. Service des monuments et sites. République et Canton de Genève. Éditions Georg. Guillaume-Henri Dufour used the Repère as a height starting point by the development of the Dufour maps from 1845 to 1864 in the graduation 1:100 000. At that time the height over sea level was estimated and decreed to be 376.86 m. Up to today, this stone forms the authoritative point of the Swiss height measurement system. However, the height was newly evaluated in 1902 to be 373.6m over sea level. This is why the data in maps of Switzerland made before 1902 differ by 3.26 m from today's official values. In the

Bronze Age The Bronze Age () was a historical period characterised principally by the use of bronze tools and the development of complex urban societies, as well as the adoption of writing in some areas. The Bronze Age is the middle principal period of ...

, these stones may have had a spiritual significance and been used in religious ceremonies. This has been hypothesized due to square holes at the top of the larger stone, discovered in 1660, which seem to have been hewed by Middle Bronze Age (c. 1500–1200 BCE) axes.Arts et monuments. Ville et Canton de Genève. Armand Brulhart et Erica Deuber-Pauli. Éditions Georg.

References

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