Palaeowind estimation of cross-bedding within the aeolian Kurkar layers of the Gaza Formation, Gaza Strip, Palestine

摘要

Coastal plain deposits of the Gaza Strip have been distinguished in the Gaza Formation (Pleistocene) of the Kurkar Group. The Kurkar layers (medium to coarse-grained calcareous sandstone) are characterized by abundant crossbedding that has two sets of cross-beds. These Kurkar layers form the ridges along the Mediterranean coast. The dip, and dip direction of the cross-beds, were measured at five sites to determine the palaeowind direction. The palaeowind directions were measured for the first time in the study area. The Kurkar layers are interpreted as having been deposited in an aeolian environment. Results at Sheikh Ejlin Ridge show that the lower set is dipping eastward (19/099), while the upper set dips northeast (23/051). At the Al Montar Ridge however, the lower set dips southeast (18/146), while the upper set dips north (19/001). These ridges are not coeval, but the precise age relationship between them is as yet unknown. However, the results indicate that there was a change in the palaeowind direction during deposition of the Kurkar layers, from westerly to southwesterly at the Sheikh Ejlin Ridge and from northwesterly to southerly at Al Montar Ridge.