Research Interests
David B. Johnson, Associate Professor of Geology

While carbonate petrology and Paleozoic depositional environments have long been among my research interests, these have until recently served my emphasis on conodont ecology and biostratigraphy. While I continue to work in these areas, I am increasingly involved in studying the nature of carbonate sedimentation and subsequent diagenesis.

Our analyses of depositional environments incorporate biotic analyses combined with more traditional sedimentological approaches, in a stratigraphic context. These techniques have been applied to mid-Paleozoic strata in New Mexico and adjacent areas in an attempt to better constrain the tectonic development and controls of carbonate sedimentation of regions like the Pedregosa basin.

Because the diagenetic history of sedimentary rocks can contain important clues to primary depositional conditions, we have become increasingly involved in diagenetic analyses. Recent studies have integrated geochemical tools including cathodoluminescence and the analyses of stable isotopes as an aid to recognition of differing diagenetic events. This information complements data pertaining to primary depositional conditions.

I continue to have an interest in the ecological controls on the distributions of mid-Paleozoic conodont species, biometric analysis of taxa, and the biostratigraphic utility of microfossils.