Crater Creep

A tall pile of tar will slowly flow downhill, ultimately spreading
into a nearly horizontal sheet of tar. Most material, under pressure,
"creeps" in this way, although rocks deform very, very slowly.

Calculations show that the growing upward bulges of large crater
floors on the Moon should occur to their current extent in only 10,000
to 10,000,000 years (a). Large, steep-walled craters exist even on
Venus and Mercury, where gravity is greater, and temperatures are hot
enough to melt lead. Therefore, creep rates on those planets should be
even greater. Most large craters on the Moon, Venus, and Mercury are
thought to have formed more than 4,000,000,000 years ago. Because
these craters show no sign of "creep," these bodies seem to be
relatively young.

a. Glenn R. Morton, Harold S. Slusher, and Richard E. Mandock, "The
Age of Lunar Craters," Creation Research Society Quarterly, Vol. 20,
September 1983, pp. 105-108.

The above study drew upon the work of Z. F. Danes, which was described
as follows: