The Monte Arci is an isolated massif in the
Uras plain in
Campidano
Campidano ( sc, Campidànu) is a plain located in South-Western Sardinia (Italy), covering approximately 100 kilometres between Cagliari and Oristano.
Geography
Geologically, it is a graben, a tectonic structure formed in the mid-Pliocene/early ...
, south-western
Sardinia
Sardinia ( ; it, Sardegna, label= Italian, Corsican and Tabarchino ; sc, Sardigna , sdc, Sardhigna; french: Sardaigne; sdn, Saldigna; ca, Sardenya, label= Algherese and Catalan) is the second-largest island in the Mediterranean Sea, af ...
,
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
. It is composed by three volcanic
basalt
Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of a ...
towers, the highest one reaching an elevation of 812 m. The inner part of the massif is composed of
trachyte
Trachyte () is an extrusive igneous rock composed mostly of alkali feldspar. It is usually light-colored and aphanitic (fine-grained), with minor amounts of mafic minerals, and is formed by the rapid cooling of lava enriched with silica and ...
.
Monte Arci is located just west of the
Giara di Gesturi, a basaltic plateau.
Monte Arci had a relevant historical role in Sardinia due to the abundant presence of
obsidian, which was used since prehistoric times for weapons and tools, and was later traded outside the island. There are also quarries of
pearlite
Pearlite is a two-phased, lamellar (or layered) structure composed of alternating layers of ferrite (87.5 wt%) and cementite (12.5 wt%) that occurs in some steels and cast irons. During slow cooling of an iron-carbon alloy, pearlite form ...
. In the territory of
Morgongiori
Morgongiori ( sc, Mragaxòri) is a ''comune'' (municipality) in the Province of Oristano in the Italian region Sardinia, located about northwest of Cagliari and about southeast of Oristano on the southern slopes of Monte Arci.
Morgongiori bor ...
there are breeds of
Giara horses.
{{Authority control
Arci