Estudo da paleoflora e suas implicações paleoecológicas nos afloramentos cretácicos da praia de morros do Camaragibe, Alagoas

Abstract

The study of four fossil woods from Cretaceous outcrops at Praia de Morros de Camaragibe, located on the northern coast of Alagoas and dated to the Aptian–Albian interval, provided significant advances in paleoecological and paleoclimatic interpretations for the region. The plant macrofossils were identified as gymnosperms based on the features observed in the secondary xylem. However, the preservation state of the specimens did not allow for precise taxonomic identification at the genus level. The anatomical characteristics preserved, in conjunction with well-documented literature on the depositional systems of the Maceió Formation and the Alagoas Basin as a whole, support the inference that the fossilization process involved gelification. Analytical techniques such as Energy Dispersive X-ray Spectroscopy (EDX) and X-ray Diffraction (XRD) applied to powdered samples revealed the predominance of amorphous and semicrystalline phases, as well as high concentrations of oxidizing chemical species that likely contributed to the gelification process. These results are directly linked to the hydrochemical and geochemical conditions of the depositional environment, associated with sedimentary systems composed of alluvial fans and turbidite systems attributed to the Maceió Formation. Furthermore, the presence of fungal structures (hyphae) observed under Scanning Electron Microscopy suggests wood-fungus interactions, which are scarcely documented in plant fossil records from this region. These structures are consistent with white rot fungi, indicating possible biological decomposition processes that occurred prior to or alongside fossilization. The findings presented in this study offer new insights into the paleoecology and taphonomic processes of the Cretaceous outcrops analyzed. Nevertheless, further studies employing complementary methods are needed to deepen the understanding of the paleoflora and associated sedimentary features, enhancing the reconstruction of paleoenvironmental conditions in the Alagoas Basin during the Cretaceous.