The Aja Mountains are to an extent made up of
granite, whereas the Salma are made up of
basalt.[1] The phrase "Hadn formation" was used by Chevremont (1982) to refer to
volcanic rocks of the area of Ha'il, and was treated by Hadley and Schmidt (1980) as being part of a
silicic and
volcaniclastic sequence referred to as the "Shammar group", in a broader, regional context.[3]
^Nader, I. A. (1989). "Rare and endangered mammals of Saudi Arabia". In Abu-Zinada, A. H.; Goriup, P. D.; Nader, L. A (eds.).
Wildlife conservation and development in Saudi Arabia(PDF).
Riyadh: National Commission for Wildlife Conservation and Development Publishing. p. 228.
Note: Mountains are sorted in alphabetical order, unless where it concerns ranges. The highest confirmed mountains in each country are indicated with 'HP', and those with the highest peak are indicated with 'HP', bearing in mind that in the UAE, the highest mountain and the mountain with the highest peak are different.
Outcrops are indicated with 'OC', and
outliers with 'OL', and
anticlines with 'AC'.
Volcanoes are indicated with 'V',
volcanic craters with 'VC',
lava fields with 'LF', and
volcanic fields with 'VF'.