Anomalias Antrópicas de Gadolínio em uma Planície Aluvionar com Sistemas de Saneamento In-situ em Campinas, SP, Brasil
As anomalias de gadolínio são reconhecidas atualmente como bons marcadores de poluição causada por água residuária. Apesar disso, ainda não existe um método padronizado para a sua estimativa. Neste artigo são comparadas quatro equações, diferentes limiarese diferentes valores de normalização para estimativa das anomalias de Gd em um estudo de caso realizado em um aquífero aluvionar onde existem sistemas de saneamento in-situ.
Assessing chemostratigraphic and biostratigraphic correlation of Ediacaran phosphorites (Bocaina, Khesen and Doushantuo Formations): Diachronic, local signals of the Neoproterozoic phosphogenic-taphonomic event
The Neoproterozoic phosphogenic event records biotic and biogeochemical changes that seem to indicate intrinsic relationships between phosphogenesis and phosphatic fossil preservation. However, chemo-litho and biostratigraphic correlations conducted on fossiliferous, phosphatic successions of the Doushantuo Formation, South China, evidence a highly heterogeneous record, featuring diachronic depositional ages, variable taxonomic diversity and inconsistent, “noisy” δ13C records.
Dawn of diverse shelled and carbonaceous animal microfossils at ~ 571 Ma
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.