The geological formation of the plateau consists of thin beds of hard silicious chalk, locally called misse, which overlie a thick bed of soft white limestone, known by the name of meleke.
The geological formation of the soil belongs to the Quaternary and Pliocene period in its upper strata, and to the Eocene and Cretaceous in the lower.
The next geological formation which is represented is the Eocene, consisting of nummulitic limestone, sandstone and schist.
The islands are volcanic, the main geological formation being Tertiary or Jurassic basalt, which occasionally protrudes through the ice-cap in high isolated blocks near the shore.
Their geological formation is metamorphic gneiss, veined with felspar and quartz, and interspersed with reddish porphyrite.
The Karroo System is par excellence the geological formation of South Africa.
From the geological formation here the name Trenton is applied to the upper series of the Ordovician (or Lower Silurian) system, and, particularly, to the lowest stage of this series.
The configuration of the hills is mainly conical and the geological formation consists of gneiss, granite (in the south) and red sandstone.
The fact that every known geological formation (except the Miocene) is represented, proves of itself how long the history has been, and how multifarious the changes.
The geological formation includes (like that of Java) three regions - the central volcanic, the southern peninsula of Tertiary limestone, and alluvial plains between the older formations.