An Acad Bras Cienc
December 2024
This study investigates ichnoassemblages characterized by spreite trace fossils from the Upper Cretaceous Snow Hill Island Formation on Vega Island, Antarctica. The succession reveals alternating heterolithic beds of sandy siltstones to very fine- to fine-grained sandstones, suggestive of a deltaic depositional setting influenced by fluctuating energy conditions. The dominance of spreite structures, such as Paradictyodora antarctica and Euflabella, suggests the prevalence of a colonization window for deposit- or detritus-feeding activity.
View Article and Find Full Text PDFShell beds, or coquinas, have a complex origin, limiting their utility in paleoecology. However, such accumulations can serve as crucial paleoenvironmental indicators, since their bioestratinomic and diagenetic properties explain the physical-chemical and biological processes of their formation, as well as the ancient environments linked to their development. In 2016, the PALEOANTAR Project sampled coquinas from the James Ross Island (Antarctic Peninsula) in Passo São José (PSJ - San José Way) and Muro do Castelo (MDC - Castle Wall), two new localities with outcrops of the lower Lachman Crags Member, Santa Marta Formation, Marambio Group, Cretaceous of Larsen Basin.
View Article and Find Full Text PDFMicroplastics are both pervasive in the marine environment and highly detrimental to it. In this study, we investigate the abundance, distribution, and characteristics of microplastics in surface waters on a transect spanning 6 major ocean current regions in the Atlantic Ocean from Scheveningen (the Netherlands) to Montevideo (Uruguay). 50 surface trawls were completed with a manta net (mesh 500 μm, cod 333 μm) and particles were analyzed in the laboratory including polymer type identification with ATR-FTIR spectroscopy.
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