Series of strata with disconformities may also be petroliferous, because beneath former erosional surfaces the top strata have induced porosity and therefore are possible reservoir rocks.
"The Economic Aspect of Geology"
C. K. Leith
The mind cannot conceive the lapse of time which has reduced this range, at an erosional speed no greater than to-day's, to its present level.
"The Book of the National Parks"
Robert Sterling Yard