Any form of repetitive sedimentary rock stratification that was deposited within a year.
This annual deposit usually consists of paired contrasting layers (varves) of alternately finer (darker) and coarser (lighter) silt or clay, reflecting seasonal variations in sedimentation (winter and summer) within the year. Varved deposits are most commonly found in glacial lakes, but they can also be found in nonglacial lakes and marine settings.