Soil Formation and Pedology
Kish Island over millions of years since its emergence has constantly been subject to environmental changes and sea level fluctuations. During glacial and interglacial periods it was frequently and sometimes for relatively long stretches affected by these changes.
In glacial periods when vast expanses of land were covered by ice and the waters of the oceans and open seas in polar regions and their margins became massive ice sheets, the oceans and open seas elsewhere fell, leaving waters to retreat from the land. In these conditions the waters of the Persian Gulf, due to this phenomenon, became shallow and from time to time dried up and its bed for long periods became a wide verdant valley full of vegetation. At that time Kish Island on the northern slope of that valley emerged as a bulky hill-like elevation about 50 meters high that was a suitable habitat for terrestrial plants and a favorable abode for animals and even humans of that era. The surface of that hill (Kish Island) during the intermittent dry periods, which sometimes lasted tens and even hundreds of thousands of years, was eroded by rains and the alluvial sediments produced by that erosion, together with dust and residues of disintegrated plant and animal tissues, accumulated on it. In interglacial periods when the climate warmed and the ice melted, the sea levels rose again, the Fars valley (the bed of the Persian Gulf) was inundated and the Kish elevation became an island. At the peak warmth and higher sea levels the island was even submerged and this time was the turn for the growth and development of corals, shells and other aquatic organisms on its surface. During these periods the impact of sea waves due to storms and winds gradually turned the calcareous remains of reefs and shells into a new shell-like sedimentary cover of marine origin (terrace) over the previous cover that had terrestrial origins.
Eleven thousand years have passed since the last glacial period when Kish permanently emerged as an island. With the relentless warming of the air and land during this time and the abundance of rainfall on the island surface, alluvial sediments settled in its depressions. Plants grew on its surface and animals populated its habitats. Gradually the remains of these plants and animals together with alluvial sediments formed a thin layer of soil over the old coral layers (remnants from the inundation period).