nInterstratification(Geol) Stratification among or between other layers or strata; also, that which is interstratified.
Century Dictionary and Cyclopedia
ninterstratificationThe state of being interstratified, or of lying between other strata; in geology, the condition of a bed, stratum, or member of an aqueous deposit, with reference to the overlying and underlying beds.
Chambers's Twentieth Century Dictionary
nInterstratificationin-tėr-strat-i-fi-kā′shun the state of lying between other strata
It presents, like the upper clay, frequent interstratification with well-bedded deposits of sand and gravel.
"The History of the European Fauna" by R. F. Scharff