Current science education efforts emphasise the need to train students to understand the nature of scientific work. In geosciences, training students to understand how science works does not only promote their interest and community engagement in the field, but also has the potential to promote awareness and ethics. However, instructional activities using an explicit and reflective approach to promote students' learning of the nature of science concepts remain scant. In this paper, a two-class unit intervention using an explicit reflective approach to the teaching of nature of science was used in an undergraduate lesson on the history of plate tectonics. We measured the influence of the lesson on students' nature of science knowledge using the Student Understanding of Science and Scientific Inquiry instrument. We collected parallel quantitative and qualitative pre- and post-intervention data from 37 community college students involved in a physical geology course. Quantitative and qualitative data analysis indicated that students' nature of science knowledge related to the tentativeness of scientific theories and the role of society and culture in science improved after the intervention unit. Results imply that geoscience educators should consider using explicit and reflective approaches when using the history of science to teach about the nature of science.