Abstract In the Bom Jardim de Goiás region, the Transbrasiliano Lineament shows evidence of a fault reactivation along NE-SW structures (main direction) and secondary directions related to subsequent events. To study the structural framework and reactivation inputs toward tectonic events, distinctive features of the northern Paraná Basin border were analyzed by integrating gamma spectrometry and radar data, both supported by field research. The remote sensing database obtained by the Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) sensor allowed detecting lineaments and morphometric derivatives. Besides, the developed morphogenetic process images attest to the importance of structural control on relief evolution while concentrating lineaments as a function of lithological and geomorphological domains. Airborne gamma-ray spectrometry data processing focused on Kd (Anomalous Potassium) and F-Parameter indices. In this context, the fuzzy logic and Index Overlay Method allowed multivalued integration that indicated hydrothermal products and weathering processes correlated with Kd and F-Parameter anomalies. Thus, the joint interpretation of lineaments, geomorphological domains, and Kd/F-Parameter anomalies allowed differentiating primary geological elements and products from surface dynamics, directly or indirectly related to tectonic reactivation processes.

Abstract In the NE edge of the Paraná Continental Magmatic Province (PCMP), compound pahoehoe, simple pahoehoe, rubbly flows, pillow lava, and simple pahoehoe/pyroclastic flows linked to ring structures with lithofacies associations have been identified. They belong to the Cretaceous Serra Geral Group. Intercalations of Cretaceous sedimentary deposits linked to the Botucatu Formation are common and can be of aeolian, alluvial, or, more rarely, lacustrine nature. These recurring intercalations indicate that volcanism and sedimentation occurred simultaneously and also attest to their intermittent nature. Geological characteristics of the study area - broadly dominant entablature structure, hypocrystalline basalts with quench textures, types of associated sedimentary deposits, and pillow lavas - support the idea that water was present during volcanic events, especially in the central portion. The recurrence of facies associations in the same stratigraphic section is discussed and is quite different from the stratigraphy that has been described for the south of the PCMP. A preliminary investigation using P2O5 content allowed the identification of five P2O5 basalt types. The distribution of these classes in the logs shows that elaborating a valid chemostratigraphic column for the region is not yet possible.

Abstract: This study covers the region between the cities of Sacramento and Araguari/Uberlândia (Minas Gerais State, Brazil), where basalt flows from the Paraná Continental Magmatic Province outcrop. The investigated rocks present tholeiitic signature, with high titanium content, and are classified as Pitanga magma-type. The preserved basalt thickness is between 10 and 200 meters and individual flows do not exceed 15 meters thick. Flows were identified as sheet lobes, smaller and thinner flows units - stacked laterally and vertically forming compound lavas -, or frontal, centimetric lobes. The basalt flows show decimetric to metric intercalations of clastic sedimentary rock, with depositional characteristics that can vary from aeolian to lacustrine, and are important markers on prevailing environmental conditions. The plagioclases are dominantly labradorite and pyroxene is augite, whereas olivine can be hyalosiderite or hortonolite/ferrohortonolite. The behavior of the major, minor and trace elements is compatible with the presence of at least two parental magmas, which were subjected to fractional crystallization mainly of plagioclase, clinopyroxene, ilmenite and magnetite. There is a chemistry distinction between basalts from Sacramento to those from Araguari/Uberlândia region, the former one showing more evolved than the last one. The high (La/Lu)N values are indicative of partial melting of a garnet peridotite, while the Rare Earth Elements (REE) values are indicative of fractional crystallization.

RESUMO: A Formação Uberaba, de idade campaniana e ocorrência restrita à região da cidade homônima, é composta de arenitos líticos e conglomerados de cor esverdeada, com possível contribuição vulcanoclástica. Nessa unidade ocorrem minerais pesados como ilmenita, granada, perovskita e magnetita, além de clinopiroxênio, plagioclásio, quartzo, calcita e apatita. A Formação Uberaba é marcada geoquimicamente por altos teores em Ba, Ta, La, Nb e Th, com padrões de elementos terras raras normalizados ao condrito fortemente fracionados (LaN/YbN = ca. 128) e planos (sem anomalia de Eu). Análises de química mineral das granadas detríticas da Formação Uberaba indicam predominância de chorlomita com afinidade com granadas crustais (G3). A proveniência sedimentar da Formação Uberaba corresponde a uma mistura de materiais de distritos alcalinos do Alto Paranaíba e derivados da erosão da Formação Serra Geral e dos grupos Canastra e Araxá. Os conglomerados produtores de diamante que ocorrem proximamente, em Romaria, foram considerados por alguns autores como correlatos à Formação Uberaba, porém a composição das granadas retiradas desses conglomerados é bastante diferente, plotando no campo de granadas mantélicas (G9/G10). Descarta-se, dessa forma, correlação entre essas duas unidades, e a Formação Uberaba, portanto, não é uma fonte provável dos diamantes aluvionares encontrados no rio homônimo.

ABSTRACT: The campanian Uberaba Formation, which crops out around the homonymous town, is composed of greenish lithic sandstones and conglomerates with possible volcanoclastic contribution. In this unit, heavy minerals such as ilmenite, garnet, perovskite and magnetite, besides clinopyroxene, plagioclase, quartz, calcite and apatite, are found. The Uberaba Formation geochemistry is marked by high grades of Ba, Ta, La, Nb and Th, with flat (no Eu anomaly) and highly fractionated (LaN/YbN = ca. 128) chondrite-normalized rare earth elements. Mineral chemistry analyses of detrital garnets from the Uberaba Formation indicate the predominance of chorlomite with an affinity to crustal garnets (G3). The sedimentary provenance of the Uberaba Formation corresponds to a mixing of materials from the alkaline districts of the Alto Paranaíba and from the erosion of the Serra Geral Formation and the Canastra and Araxá groups. Diamond-producing conglomerates which crop out nearby, in Romaria, were considered by some authors as correlated to the Uberaba Formation. However, the composition of garnets recovered from those conglomerates is different, plotting in the field of mantle garnets (G9/G10). We consider, then, that those units are not correlated, and that the Uberaba Formation is not a possible source for the alluvial diamonds found in the homonymous river.