Within Charles Sanders Peirce's semiotical theory, two different kinds of creative metaphorical reasoning in science can be identified. One of these, the building of remainder metaphors, is especially important for creating new scientific models. We show that the conveyor belt metaphor provides an excellent example for Peirce's theory. The conveyor belt metaphor has recently been invented in order to describe the oceanic transport system. The paradigm of the oceanic conveyor belt strongly influenced the geoscience community and the climate change discussion. After identifying structures of metaphorical reasoning in science (section 2), these structures are examined in section 3 for the conveyor belt metaphor in the field of oceanography. Finally, concluding remarks are given in section 4. © 2000 Kluwer Academic Publishers.