Geology of The Iberian Peninsula - Balearic Islands

Balearic Islands

The Balearic Islands are on a raised platform called the Balearic Promontory.

Majorca:

• Port d’es Canonge Formation – Guadalupian
• Asa Formation – Lopingian Permian
• Son Serralta Formation Anisian Triassic

Minorca:

• Saxonian Facies = Asa Fm Lopingian Permian 260–251 Ma
• Conglomerate – Olenekian Smithian substage 249 Ma
• Buntsandstein from Olenekian to Anisian Triassic 248–237 Ma
• Muschelkalk Ladinian 237–238 Ma

The southern margin consists of a narrow shelf where carbonates are deposited. Sediments spill over the ledge. South of Cabrera Island between Formentera and Cabrera islands is a small volcanic province with a few dozen outlets. The slope to the south of the shelf is the Emile-Baudot escarpment. It only has one Canyon, the Menorca Canyon, with Menorca Fan at its base. The crust in the Balearic Promontory is 25 km thick. The lithosphere is only 30 km and there is a low seismic velocity asthenosphere below.

In Menorca there are extensive outcrops of the Variscan basement. In the Triassic deposits similar to those in Germany were formed. In the early Jurassic it was covered with shallow sea water and limestone formed. From Middle to Late in the Jurassic marl and limestone formed in deep water. In the Cretaceous marl and shallow water limestone was formed. From the Late Cretaceous to the Paleogene there were few deposits. From the Eocene there is some shallow water limestone in the southeast. During the Eocene to early Oligocene, the island of Sardinia was located northeast of the Balearic Promontory (Menorca). Sardinbia and Corsica rotated away from 19 to 15 Ma. From the Oligocene there is some conglomerate.

In the Neogene orogeny (mountain building) started again. As the ground was deformed conglomerate, calcareous sandstone, limestone, and calcareous turbidites appeared. During the orogeny from Late Oligocene to Middle Miocene the ground was shortened (compressed) by 50%. On the southeast of Majorca overturned folds were produced in the Late Oligocene to Langhian. In the Middle and Late Miocene (mostly Serravallian) the ground was stretched (extended) and faults formed and created basins. In the Late Miocene they filled with water and sediment. After the orogen, limestone marl and calcareous sandstone were added. Later in the Pliocene till now contraction has taken place again.

From the Early Miocene there are two volcanoes of calc-alkaline volcanics.

South of the Balearics there is the Algerian Basin floored by oceanic style crust from 4 to 6 km and a moho less than 15 km deep. The floor of this basin is 0.5 km of Pliocene to Quaternary sediments overlying the Messinian evaporites 1.2 km thick, which from diapirs into the sediments.