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The Bom Jardim de Goiás copper deposit is a remarkable example of a deposit formed in a Neoproterozoic juvenile arc in the South American Platform during the assembly of Gondwana. The deposit is inserted in the western margin of the Arenópolis Magmatic Arc, in the Tocantins Province. The host rocks comprise a volcanosedimentary sequence of intermediate to acid composition interpreted as crystal and ash tuffs. The tuffs represent calc-alkaline volcanism of rhyodacitic to dacitic composition, with lithogeochemical and biotite chemistry characteristic of magmas from intra-oceanic arcs. The tuffs are commonly cut by veins and veinlets with no preferential orientation and show ε Nd(t) values between +3.5 and +7.4 and T DM model ages ranging from 0.8 to 1.1 Ga, consistent with juvenile magmas generated in magmatic arc settings. Intrusive bodies in the volcanosedimentary sequence are represented by hornblende-biotite monzogranite, interpreted as Serra Negra Granite, and biotite syenogranite defined as Macacos Granite. The granites have geochemical characteristics of type I calcalkaline granites, generated in a post-collision setting. Tholeiitic basalts intercalated with tuffs, interpreted as flows, show geochemical affinity with volcanic arc basalts, whereas the dikes that crosscut the granites have compositions characteristic of intra-plate tholeiitic basalts. The petrological data of the host and country rocks of the Bom Jardim de Goiás area reveal an important production of calc-alkaline magma in a magmatic arc setting in western Goiás around 750 Ma, genetically related to copper mineralization, and the generation of a non-mineralized post-collisional magmatism at 540 Ma.

The Novo Progresso Formation, located in southeastern Tapajós Gold Province, at its boundary with the Iriri-Xingu Domain, south of the Amazonian Craton, is composed of quartz-and lithic-arenites and siltstones with volcanic/volcanoclastic contributions, and was deposited in fluvial and lake systems. Reconnaissance detrital zircon U-Pb LA-ICP-MS data on a lithic arenite indicate maximum depositional age around 1840 Ma, whereas structural relationships suggest a minimum age of 1780 Ma. The zircon age spectrum shows two well-defined peaks at 1846 and 1968 Ma, and statistically secondary peaks ranging from 2185 Ma to 2973 Ma. εHf values vary from +8.1 to -14.5 (T DM = 2.13 to 3.95 Ga), whereas the εNd values range from -2.5 to -3.3 (T DM = 2.31 to 3.21 Ga), with one positive value of +4.5 (T DM = 1.81 Ga). These data and the lithological composition indicate that surrounding Orosirian rocks from Tapajós and Iriri-Xingu were the main sources for the sediments, with subordinate contributions from older and more distant domains of the Amazonian Craton. In addition, the Hf systematics suggest a ~2.50 Ga-old crustal growth event and a ~3.95 Ga-old hidden component in the eastern portion of the Amazonian Craton. The deposition of the Novo Progresso Formation is related to the development of the large Orosirian intracratonic rift system known as Uatumã Silicic Large Igneous Province (1.89-1.80 Ga), which cut across the Amazonian Craton, following the final stages of magmatism in the Tapajós Gold Province.

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The Tapajós Gold Province, central portion of the Amazonian Craton, is one of the main metallogenic provinces in Brazil, but lack geological studies at an appropriate scale in its southeastern portion. Fieldwork, petrography, and high-resolution airborne geophysics (magnetometry and gamma spectrometry) allowed us to produce a new map at the 1:100,000 scale. In this study, we identified two new geological units: (1) the volcanic and pyroclastic rocks of the Vila Riozinho Formation, previously attributed to the Iriri Group, including a newly described facies of this formation, which comprises a group of rocks with the highest magnetic contents of the study area, and (2) the Serra Alkali Feldspar Granite, which intruded into the Vila Riozinho Formation. Based on available geochronological information these units can be associated to a volcano-plutonic event that occurred in the Orosirian period, at about 1.98 Ga. In addition, our work allowed us to define better the areas of occurrence of other units. The Parauari Intrusive Suite and Iriri Group areas were strongly reduced, whereas the areas of the Creporizão Intrusive Suite and of the Novo Progresso Formation were increased.