Geology

Geologically, a complex of ancient crystalline rocks forms the Saint Katherine Protectorate with some rocks, such as the Feiran gneiss, dating 1,100 million years. Grey granites dating back 850 million years are among the oldest rocks while the more common rose granites are younger at about 600 million years old. Ancient pink, white and yellow sandstones dating from the Palaeozoic to Cretaceous period skirt the crystalline rocks to the north and west of the protectorate.

The protectorate contains some of the highest peaks in Egypt, including Gebel Katherine (Mount St. Katherine) the country’s highest summit (2,641 meters), Gebel Um Shomar (2,586 meters), Gebel El Thabt (2,439 meters), Mt. Sinai or Gebel Musa (2,280 meters) and Gebel Sirbal (2,070 meters). These mountains are composed of rocks of various types, colours and ages; for instance Gebel Katherine is made of andesite porphyry, a volcanic rock about ten million years old. Neighbouring mountains of Gebel Ferrah, Gebel Safsafa and Mount Sinai are formed from pink granite, a 580 million year old basement rock. However Mount Sinai’s summit is made of more recent volcanic rock, about ten million years old.