Last month, Dr. Julie Bartley and Dr. Laura Triplett each had new research published. Dr. Bartley published an article titled “Chemostratigraphy of the Late Mesoproterozoic Atar Group, Taoudeni Basin, Mauritania: Muted isotopic variability, facies correlation, and global isotopic trends”, in which she and co-authors Linda Kah and David Teal used the geochemistry of 1.2 billion-year-old limestones to establish timelines within the basin and to reveal that the ancient ocean possessed regional differences in chemistry. Figure 3 Figure 3 (AtarChemoS) shows outcrop photos of some of these ancient deposits, including reef-like stromatolites, thinly layered, shallow-water carbonates and disrupted strata. Figure 5 Figure 5(AtarChemoS)shows multiple generations of mineral growth within the reef (top) and the geochemical variability that they preserve (bottom). Such variation is interpreted to reflect calcite growth under different chemical conditions at the time the ancient carbonate platform was developing.
Dr. Triplett published an article titled “Changes in amorphous silica sequestration with eutrophication of riverine impoundments”, in which she and co-authors Dan Engstrom and Daniel Conley measured how phosphorus pollution in the St. Croix and Mississippi Rivers (MN) has decreased the amount of silica being transported by those rivers.