What is onlap?

Answer 1

The termination of shallowly dipping, younger strata against more steeply dipping, older strata, or the termination of low-angle reflections in seismic data against steeper reflectionThe termination of shallowly dipping, younger strata against more steeply dipping, older strata, or the termination of low-angle reflections in seismic data against steeper reflections. Onlap is a particular pattern of reflections in seismic data that, according to principles of sequence stratigraphy, occurs during periods of transgression. s. Onlap is a particular pattern of reflections in seismic data that, according to principles of sequence stratigraphy, occurs during periods of transgression.