Abstract: In the geologic literature ,and on the published maps of Turkey theterm flysch is frequently applied to a great variety of deposits of Cretaceous ,and Tertiary age. Since most of the geologic work has been carried out by European-trained geologists, this is not surprising,It is, however, somewhat baffling to the American geologists ,and acertain reluctance on their part to use the term can be observed. Thishas also its good reasons, as will be pointed out later.There is no doubt that the usage of the term flysch has been confusing in the past and its application abused, which has led many earneststudents of the problem to advocate complete abandoning of the term.However, not only are we still facing its application in the publications of all areas with alpine-type geology, we also feel that the termflysch has a definite value in those areas, if properly defined ,and understood.The purpose of this talk, therefore, is to take a critical look at thedefinition ,and usage of the term flysch ,and to cite a few examples of itsusefulness,Since the term molasse is usually connected with the term flysch ,and since there seems to exist some confusion in the differentation ofthe two, the following discussion is pertaining to both terms.