The qualitative analysis of academic discourse is valuable for understanding how the resources used for expressing authorial positioning act both as the reflection and as the per- petuation of a community's value system. In geology, this value system continues to be largely centered around demonstrating a requisite knowledge of ''field culture'', where having been in the field is crucial to establishing credibility, authority and field competence. The stance and position taken for providing concrete evidence of this activity is the basis by which contribu- tions are recognized and evaluated by the community. At the same time, modern scientific reporting conventions impose a ''textual silence'' on the explicitness of the field account, resulting in the use of implicit strategies to express insider concerns. Accordingly, interweav- ing clusters of features, as evaluative evidence, work to discreetly confirm the author's success as a field researcher, by persuasively permitting the community to evaluate his credibility and his competence. This paper describes the basis for the evaluational practices of the field geology community, though a qualitative analysis of geologists' implicit strategies coupled with the situated analysis of the Field Account part-genre, its past and present disciplinary practices.