What hypotheses do elementary pre-service teachers make and what do they base them on when analyzing the formation of a diapir?

There is a broad consensus in science education regarding the need to integrate the big scientific ideas with scientific practices in the classroom. Using evidence and evaluating knowledge have been recognized as the key scientific practices. Besides, learning process in geology is conditioned by the historical and interpretative nature of this science, and by the need to contextualize the phenomena modelled in space and time. Therefore, field and cartographic work is often essential for the construction of geological models. Taken this into account, a teaching sequence about a diapir has been designed and carried out with elementary pre-service teachers. Students’ group discussions after the field trip were analysed. The results show: (1) a trend towards catastrophism and destructive landscape processes, (2) problems in deciding whether or not a data is relevant, (3) significant variation in the data used and the hypotheses made by students in activities prior to cartographic work comparing to those made in the subsequent activities, and (4) the importance of “visualizing” the three-dimensional structure of strata and relating it to other known images so that students propose hypotheses closer to the scientific model.