The Carved out Nile

"From Aswan in the south to Cairo, the Nile occupies a long, reasonably flat valley generally12 to 18 miles wide. 

Typically, it was carved some 500 ft deep into the limestones of the desert plateau that covers most of Egypt. 

The Valley of the Kings sits along one of the limestone cliffs.

On top of the plateau was a scattered deposit of gravel and cobbles, both of chert. 

Chert is a form of quartz, but with very fine-grained texture comprising microscopic crystals. It is incredibly hard—impossible to scratch with a steel knife.

Some chert cobbles were more than 6 in long. 

They were well rounded, indicating they had been transported by

water. Some cobbles were broken, and dented with circular marks, called percussion marks. These indicate that they smashed into each other as they were carried along by the torrential water flow that rounded and broke them. Significantly, percussion marks are not forming on such hard rocks today, even in the most powerful modern flood events.

The chert would have originated from chert layers and nodules within the limestone when massive water flows catastrophically eroded the valley. 

While this sort of erosion creates a wide valley in rapid time, some portions of the limestone originally deposited during the Flood’s Ascending Phase remain. These are called erosional remnants—such as the Giza plateau near Cairo.

This erosional remnant in a broad valley 

---with water-rounded hard rocks on top that are broken 

---and contain percussion marks indicates that the Nile River Valley was carved by an extraordinarily torrential water flow. 

The Recessive Stage of Noah’s Flood would produce just such a flow, as the floodwaters that covered the whole of the African continent drained from the landscape." 

CMI

In the six hundredth year of Noah's life, in the second month, the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened. Genesis 7:11