Genesis 11:3

Let us make brick - It appears they were obliged to make use of brick, as there was an utter scarcity of stones in that district; and on the same account they were obliged to use slime, that is, bitumen, (Vulg). ασφαλτος , (Septuagint) for mortar: so it appears they had neither common stone nor lime-stone; hence they had brick for stone, and asphaltus or bitumen instead of mortar.