Varv er betegnelsen for et lagdelt sediment, der udviser en årstidsvariation. I Sverige er der etableret en såkaldt varvkronologi flere tusinde år tilbage i tiden.
De Geer, G. (1940), Geochronologia Sueccia Principles. Kungl. Svenska Vetenskapsademiens Handlingar, Tredje Serien. Band 18 No.6.
Lowe, J.J. and Walker, M.J.C. (1984), Reconstructing Quaternary Environments. Longman Scientific and Technical.
Sauramo, M. (1923), Studies on the Quaternary varve sediments in southern Finland. Comm. Geol. Finlande Bulletin 60.
Wohlfarth, B. (1996), The chronology of the Last Termination: A review of radiocarbon-dated, high-resolution terestrial stratigraphies. Quaternary Science Reviews15 pp. 267-284.