geologia

Abstract: The geodynamic understanding of the Riacho do Pontal Orogen, in the Borborema Province, NE-Brazil, has progressed substantially in the last decade, mainly from geochemical and isotopic studies.

The record of thalloid macrofossils in the North-Northwest region of the Paraná Basin is less studied compared to that of invertebrate paleofauna in the same area. Consequently, the lack of important information regarding the niches occupied by thalloid embryophytes during early land colonization in this coastal paleoenvironment is evident.

Brazilian pre-salt carbonates encompass more than 70% of the total oil and gas produced in the country nowadays and yet, present several challenges such as heterogeneous composition in mineralogy with the presence of Mg-clays, a complex pore network and diagenetic processes, e.g., dolomitization, silicification and cementation. Rock physics provides a powerful route to understand the elastic behavior of rocks by connecting geology and geophysics. It is known that pore type determination is crucial to understand this behavior.

Lower Cretaceous carbonates in the pre-salt succession in the Santos Basin, eastern Brazil, are highly heterogeneous in terms of their reservoir characteristics as a result of depositional and diagenetic factors. Electrofacies have widely been used for reservoir zonation and, when allied with computer-based methods such as neural networks, may help with the study of such complex reservoir rocks and with the identification of high-quality reservoir zones.

Deciphering the evolution of ecological interactions among the metabolic types during the early diversification of life on Earth is crucial for our understanding of the ancient biosphere. The stromatolites from the genus Conophyton cylindricus represent a datum for the Proterozoic (Meso to Neoproterozoic) on Earth. Their typical conical shape has been considered a result of a competition between microorganisms for space, light and nutrients.

The reactivation of faults may directly modify their permeability and the integrity of the petroleum system seal.

The main copper deposits of the Carajás Mineral Province are grouped into: i) iron oxide-copper-gold (IOCG), and ii) granite-related Cu-Au. They were formed during multiple mineralizing events in the Neoarchean (ca. 2.7; ca. 2.5 Ga) and Paleoproterozoic (ca. 2.1; ca. 1.8 Ga). A combination of non-composition and composition data analysis, molar element ratio, and principal component analysis using a lithogeochemical dataset (n = 1040) has been applied to recognize geochemical associations in these deposits.