A small but significant find made during a geological survey provides evidence of the oldest human presence yet discovered along the northernmost margin of Egypt's Nile delta.
A rock fragment carried by humans to the site was discovered in a sediment core section north of Burullus lagoon near the Mediterranean coast.
Radiocarbon analysis of plant-rich matter in the mud surrounding the object provides a date of 3350 to 3020 B.C., the late Predynastic period.
There should really be lots of sites underneath several meters of Nile mud in the Delta. Most of the sites accessible to archaeologists are only there now because they were built on topographic rises in the underlying sediment. Underlying much of the Delta is a fairly coarse sand of probably Pleistocene age known as gezira. It's thought that settlements were built on these things because they would afford refuge during the yearly flood.
The Delta and indeed most of the Nile valley have been prograding (depositing sediment) due to the rise in sea levels since the end of the Pleistocene. That's one reason deeply stratified settlement sites are fairly rare in Egypt.