تكوّنت الجبال بإحدى أسباب تكوّن الحجارة، والأرجح أنها طينٌ متلاصق جفّ ببطء وتحجّر عبر أحقاب لا سجلّ لنا بها. ويبدو أن هذا العالم المسكون كان في الأزمنة الغابرة غير صالح للسكن، بل ربما كان مغمورًا تحت المحيط. ثم انكشف شيئًا فشيئًا، فتحجّر مع تعاقب الدهور.

“Mountains have been formed by one [or other] of the causes of the formation of stone, most probably from agglutinative clay which slowly dried and petrified during ages of which we have no record. It seems likely that this habitable world was in former days uninhabitable and, indeed, submerged beneath the ocean. Then, becoming exposed little by little, it petrified in the course of ages.”Avicenna — De congelatione et conglutinatione lapidum, being sections of the Kitāb al-shifâ: The Latin and Arabic texts, edited with an English translation of the latter and with critical notes (1927)