Changes

[[file:exploring-for-stratigraphic-traps_fig21-17.png|300px|thumb|{{figure number|1}}Planktonic and foraminiferal data taken on a 30-ft (9.1-m) interval show abundance peaks crossing a sharp log break from a thin carbonate to marine shale.]]

[[file:exploring-for-stratigraphic-traps_fig21-17.png|300px|thumb|{{figure number|1}}Planktonic and foraminiferal data taken on a 30-ft (9.1-m) interval show abundance peaks crossing a sharp log break from a thin carbonate to marine shale.]]

A downlap surface (DLS) is a marine flooding surface onto which the toes of prograding clinoforms of the overlying highstand systems tract downlap. The surface represents a change from a retrogradational depositional pattern to an aggradational pattern. It is the surface of maximum flooding, recognized by downlap of overlying units and apparent truncation of underlying units. A downlap surface is common at the base of prograding deltas and the top of submarine fans.

A downlap surface (DLS) is a marine flooding surface onto which the toes of [[Well_log_sequence_analysis#Parasequence_stacking_patterns|prograding]] clinoforms of the overlying highstand systems tract downlap. The surface represents a change from a retrogradational depositional pattern to an aggradational pattern. It is the surface of maximum flooding, recognized by downlap of overlying units and apparent truncation of underlying units. A downlap surface is common at the base of prograding deltas and the top of submarine fans.

==Example: identifying MFS with biostratigraphic data==

==Example: identifying MFS with biostratigraphic data==