The Zagros Mountains, Iran
The Zagros Mountains
The Zagros Mountains owe their origin to the collision of two tectonic plates, namely the Arabian and Asian plates. This collision began during the middle Miocene period, some 13 million years ago, and continues to this day at a rate of 1.6 inches (4 centimeters) each year. This means that the Zagros range is being pushed steadily higher – like the Himalayan and associated ranges further to the east – and this is a region that is regularly hit by earthquakes.
The range, which extends from the Diyala River (a tributary of the Tigris) in the northwest to beyond the ancient city of Shiraz to the southeast, is formed mostly from limestone and shale and consists of numerous parallel ridges with intervening valleys. The ridges increase in height to the east until they merge with a high plateau that lies at about 5,000 feet (1,500 metres).
The western side of the Zagros range, which includes much of the Kurdish areas of Iraq and Turkey, is drained by strongly flowing rivers that are fed by snowmelt and rainfall of some 40 inches (100 cms) a year.
The higher slopes of the Zagros are covered in oak, sycamore, maple and beech. Willow, plane and poplar trees grow in the higher mountain ravines, while lower down are found walnut, fig and almond plantations that take advantage of the naturally fertile soils in the valleys.