geologia

Archean to Paleoproterozoic crustal segments are widely recognized as basement inliers within the Neoproterozoic orogenic belts of the Pan-African/Brasiliano orogeny. For example, the Canindé do Ceará Complex, in the northern Borborema Province, NE Brazil, comprises a large domain of Paleoproterozoic high-grade metamorphic rocks with a protracted tectonic history. This complex is dominantly represented by sillimanite- and graphite-bearing metasedimentary rocks with associated tonalitic to granodioritic orthogneisses.

Large gold provinces commonly show complicated mineralization histories, and the Paleoproterozoic Alta Floresta, one of Brazil's most exciting Au–Cu mineral provinces, is a good example. The current models define four deposit types, all connected to a single (1.88–1.75 Ga) magmatic–hydrothermal event. However, long Province history, diverse geodynamic environment and older ages of type-1 mineralization weaken the single metallogenic event and enable the hypothesis of overprinted mineral events.

Fossilized feces (coprolites) are remarkable tools for paleobiology and paleoecology assessment.

Abstract: Oil spills cause long-lasting mangrove loss, threatening their conservation and ecosystem services worldwide. Oil spills impact mangrove forests at various spatial and temporal scales. Yet, their long-term sublethal effects on trees remain poorly documented. Here, we explore these effects based on one of the largest oil spills ever recorded, the Baixada Santista pipeline leak, which hit the mangroves of the Brazilian southeastern coast in 1983.

Khondalite belts are of special importance is delimiting old suture zones and in palaeocontinental reconstruction of Precambrian terrains. In the South-American Platform, khondalitic rocks surround cratonic areas and Archean blocks reworked in the Neoproterozoic, an example of which being the Ceará Khondalite Belt (CKB). Located in the northern portion of the Borborema Province in NE Brazil, CKB is here described by means of its petrographic, structural, and LA-SF-ICP-MS zircon and monazite U–Pb geochronological characteristics.

The Barra Velha carbonates are widely known for their complexity regarding facies, diagenetic features, and depositional history. The absence of recent analogues representing the depositional setting of these rock formations leaves many uncertainties concerning the sedimentary process that generated them.

Storm deposits are common in geological records and encompass a variety of fossil assemblages affected by taphonomic processes that can biased fossil preservation. Here, we describe a microfossil bonebed to demonstrate the role played by certain filters in the final composition of storm-generated fossil accumulations. These layers are recurrent in the Paraná Basin and possibly in other localities of Gondwana, outcropping over 1000 km in the Permian units of the basin.

Spiders (Order Araneae) can be found in all continents, except Antarctica. This order has a long evolutionary history that began during the Paleozoic Era. Despite this prolonged span and the diversity of extant species, the fossil record of spiders is relatively modest, with most specimens preserved in amber and found in the Northern Hemisphere. Taubaracna maculosa nov. gen.

The origin of the air sac system present in birds has been an enigma for decades. Skeletal pneumaticity related to an air sac system is present in both derived non-avian dinosaurs and pterosaurs. But the question remained open whether this was a shared trait present in the common avemetatarsalian ancestor. We analyzed three taxa from the Late Triassic of South Brazil, which are some of the oldest representatives of this clade (233.23 ± 0.73 Ma), including two sauropodomorphs and one herrerasaurid.