(The appearance of) crosswise structure in a system of ripple marks on sedimentary rock, providing an indication of prevailing currents or flows at the time of deposition.
Origin
Mid 19th century.
Definition of ripple drift in US English:
ripple drift
noun
Geology
(The appearance of) crosswise structure in a system of ripple marks on sedimentary rock, providing an indication of prevailing currents or flows at the time of deposition.