The fossil beach and reef terraces of the Gulf of Aqaba coast, Jordan—its environment, formation, and relation to mountain uplifting mechanism

Abstract

In the southern part of the eastern Jordanian coast of Aqaba Gulf at least three raised fossil reefs were mapped. These fossil reefs were deposited on alluvial fan deposits and are laterally connected with clastic shore sediments simultaneously deposited with their corresponding reef. The highest mapped fossil reef lies at an elevation of about 75 m above present sea level, the other two lie at lower elevations of around 60 m above sea level and 20 m above sea level. Geological and paleontological evaluation places the highest reef as the most recent fossil reef. Sea level had been following the rises and falls caused by subsequent glacial growths and the sea, since about 20,000 years, has only been rising. The alluvial material into and onto which the beech, lagoon, and reefs had been deposited during or before the time of the Eemian Interglacial and it had become detached from its source area during or subsequent the moist time of the last interglacial period. It is assumed by previous studies that the reefs are still younger than 200,000 years, and in that case the rise of the fossil reefs is due to taphrogenic and epirogenic movements and has not been caused by eustatic fluctuations. Such movements have affected the Gulf of Aqaba and the Jordan Rift Valley since Oligocene times.