Water gaps of necessity often cut entirely through a barrier range and Riverine gaps may create canyonscanyons such as the riverine gaps of the Danube River, Lehigh River Gorge, the Colorado River's Grand Canyon , the Genesee River  may expose millennia of strata in the local rock column writing the geologic record. Such cuttings
Water gaps of necessity often cut entirely through a barrier range and riverine gaps may create canyons such as the riverine gaps of the Danube River, Lehigh River Gorge, the Colorado River's Grand Canyon and the Genesee River . Such cuttings may expose millennia of strata in the local rock column writing the geologic record. 
R
Riverine
riverine
R
canyonscanyons
canyons
R
,
and
A
. Such cuttings
D
Such cuttings