While the features of the scientific research article have been widely investigated in numerous disciplines over the past 15 years, relatively scant attention has been paid to the important discipline of geology. Moreover, within the sub-discipline of petrology, we find a sub-section as yet unrecognized in the extensive literature on the research article. The " Geological Setting ", an introductory part-genre occurring before the onset of petrological analysis, is a multi-functional description which frames researchers' results within their geological context. It is argued that this part-genre is not only a complex of the topography, geological history and characteristics of the research site, but also serves to establish the authors' credentials and authority as experts, while allowing them to maneuver through conventional modesty in presenting terrain results. Similarities at the macro-level and general discourse structure are found in both the French and English texts, with important stylistic differences on a local level.