Publications by authors named "Marly Babinski"
The Ediacaran-Cambrian transition documents a critical stage in the diversification of animals. The global fossil record documents the appearance of cloudinomorphs and other shelled tubular organisms followed by non-biomineralized small carbonaceous fossils and by the highly diversified small shelly fossils between ~ 550 and 530 Ma. Here, we report diverse microfossils in thin sections and hand samples from the Ediacaran Bocaina Formation, Brazil, separated into five descriptive categories: elongate solid structures (ES); elongate filled structures (EF); two types of equidimensional structures (EQ 1 and 2) and elongate hollow structures with coiled ends (CE).
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- Marinas play a crucial role in maritime leisure and transport but can negatively impact sediment quality in their vicinity.
- This study analyzed sediment samples from Bracuhy marina in Southeast Brazil to track metal contamination linked to antifouling paints, focusing on elements like Cu, Zn, Pb, Cd, and Sn.
- Results showed significant increases in Cu and Zn levels, up to 15 and 5 times the baseline, indicating severe contamination coinciding with marina activities, highlighting the environmental consequences of such operations.
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- The study examines copper contamination in a Brazilian mangrove, focusing on its sources and stable isotopes as tracers.
- It utilizes multi-isotopic methods and sediment analysis to identify two key stages of copper evolution: pre-1965 showing natural landscape changes and post-1965 indicating increased anthropogenic copper input.
- Findings highlight the effectiveness of copper isotopes as environmental tools for tracing human impacts on mangrove ecosystems while enhancing understanding of copper dynamics over time.
The availability of nutrients in seawater, such as dissolved phosphorus (P), is thought to have regulated the evolution and activity of microbial life in Earth's early oceans. Marine concentrations of bioavailable phosphorus spanning the Archean Eon remain a topic of debate, with variable estimates indicating either low (0.04 to 0.
View Article and Find Full Text PDFMicrobial activity is often invoked as a direct or indirect contributor to the precipitation of ancient chemical sedimentary rocks such as Precambrian iron formations (IFs). Determining a specific metabolic pathway from the geological record remains a challenge, however, due to a lack of constraints on the initial conditions and microbially induced redox reactions involved in the formation of iron oxides. Thus, there is ongoing debate concerning the role of photoferrotrophy, that is the process by which inorganic carbon is fixed into organic matter using light as an energy source and Fe(II) as an electron donor, in the deposition of IFs.
View Article and Find Full Text PDFThe application of zinc (Zn) isotopes in bivalve tissues to identify zinc sources in estuaries was critically assessed. We determined the zinc isotope composition of mollusks (Crassostrea brasiliana and Perna perna) and suspended particulate matter (SPM) in a tropical estuary (Sepetiba Bay, Brazil) historically impacted by metallurgical activities. The zinc isotope systematics of the SPM was in line with mixing of zinc derived from fluvial material and from metallurgical activities.
View Article and Find Full Text PDFWe developed an analytical method and constrained procedural boundary conditions that enable accurate and precise Zn isotope ratio measurements in urban aerosols. We also demonstrate the potential of this new isotope system for air pollutant source tracing. The procedural blank is around 5 ng and significantly lower than published methods due to a tailored ion chromatographic separation.
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