Abstract Any archaeological site, according to the Brazilian Federal Constitution, is a patrimony of the Union; consequently, when crimes against this cultural patrimony occur, it becomes the responsibility of the Federal Police of Brazil. In 2013, there was a complaint to the Brazilian Federal Public Prosecutor's Office about the depredation of an archaeological site and forced withdrawal of the indigenous people because of the construction of a multimodal port in the city of Guaíra, in the state of Paraná, in southern Brazil. Thus, the Technical–Scientific Sector of the Federal Police Department, in partnership with Brazilian universities, used standard geophysical methods such as ground-penetrating radar (GPR) to investigate and locate buried archaeological targets. This paper discusses the results of 2D and 3D investigations in the Tekoha Jevy indigenous village, located in Guaíra County. In the field, 32 parallel sections of GPR data were acquired using 250 and 700 MHz shielded antennas. The results showed several anomalies, two of which were subjected to field checks using excavations, which revealed several artefacts such as ceramic fragments associated with ancient indigenous occupations on the banks of the Paraná River.

Abstract This paper presents the investigation of fraud and of the theft of metal acquired by a Brazilian company from a Chinese supplier. Zinc ingots were transported by ship from China to the city of Londrina, in Paraná State, Brazil. However, they were substituted at some point during their journey, and replaced with bags containing fine crushed rock. In this case of a classic ‘substitution’ it was possible to use geological methods to investigate the crushed rock. As such, the mineralogical, petrological and isotope analysis showed the replaced rock did not originate from a Brazilian provenance. Therefore, the substitution possibly occurred before the cargo's arrival in Brazil. An inadequate chain of custody of the cargo, during transportation from Asia to Brazil, including the onward journey from Paranaguá to Londrina, is likely to have provided the opportunity for the material exchange to take place. Collaboration between the Brazilian Federal Police and geological experts based in academia enabled the crime to be investigated and solved.

Abstract Soil traces can be used as evidence in criminal investigations due their transferability, great variability and persistence. The soil samples originated from a crime scene that occurred in the Curitiba Metropolitan Region, Brazil. Physical, chemical and mineralogical analyses were carried out on the soil samples. All results were statistically analysed using multivariate analysis (PCA) to verify the relative positioning of soil traces which had been recovered from a stolen safety deposit box (SDB) from a vehicle suspected of being used in the SDB transportation, and from the site allegedly used in the opening of the SDB. The methods employed were effective in discriminating between the sampling sites. The soil from the site used in the opening of the SDB could be excluded as being the location where the soil transferred to the SDB had originated as it was different in many characteristics.

Abstract A palaeogeographical reconstruction of the South American and African continents back to anomaly C34 (84 Ma) brings together the Rio Grande Rise (RGR) and the central portion of the Walvis Ridge (WR), thus the RGR–WR aseismic ridges may have a common origin. If the construction of the RGR–WR basaltic plateau took place mainly between 89 and 78 Ma, as indicated by the ages of the basalts sampled by DSDP wells, then the basaltic magmas are the result of an ‘on-ridge’ volcanism. Once separated, the normal sea-floor spreading and thermal subsidence of the RGR and WR ridges continued until approximately 47 Ma when an Eocene magmatism took place in the RGR. In the WR, a younger volcanism is observed in the Guyot Province. The available geochemical and isotope data of the WR–RGR basalts do not indicate the participation of the continental crust melting component. Incompatible trace element ratios and isotope signatures of the basalts from the RGR–WR ridges are distinct from the present-day Tristan da Cunha alkaline rocks, and are nearly identical to the high-Ti Paraná Magmatic Province (PMP) tholeiites (133–132 Ma). Both the high-Ti PMP and the WR–RGR basalts are characterized by moderate initial 87 Sr/ 86 Sr and low 206 Pb/ 204 Pb isotope ratios [Enriched Mantle I (EMI) mantle component], suggesting melting from a common source, with significant participation of sub-continental lithospheric mantle (SCLM). A three-dimensional (3D) flexural modelling of the RGR and WR was conducted using ETOPO1 digital topography/bathymetry and EGM2008-derived free-air anomalies as a constraint. The best fit between the observed and calculated free-air anomalies was obtained for an elastic plate with elastic plate thickness ( T e ) of less than 5 km, consistent with an ‘on-ridge’ initial construction of the RGR–WR. The modelling of the crust–mantle interface depths indicates a total crustal thickness of up to 30 km in the RGR–WR. Flexural analysis reinforces the geological evidence that RGR was constructed during two main magmatic episodes, the tholeiitic basalts in the Santonian–Conician times and the alkaline magmatism in the Eocene. Geochemical and geophysical evidence, which rules out the classical deep-mantle plume model in explaining the generation of basalts of these volcanic provinces, is presented. Finally, three models to explain the geochemical and isotope signatures of RGR–WR basalts are reviewed: (1) thermal erosion of SCLM owing to edge-driven convection; (2) melting of fragmented or detached SCLM and lower crust; and (3) thermal erosion at the base of the SCLM with lateral transport of enriched components by mantle flow.

In the early Pennsylvanian, glacial lobes draining from an ice sheet probably centered on the northern highlands of Namibia (Windhoek ice sheet) reached the eastern margin of the marine-flooded Paraná Basin in southeastern and southern Brazil. Here, the glacier lobes extended at least 50 km across the depositional surface and terminated in a grounded tidewater system. The late Paleozoic paleolatitude of 40°–50°S of the Paraná Basin is consistent with a temperate warm-based regime for the glaciers. Accumulation of glacially influenced sediments in the main northern depocenter of the rapidly subsiding cratonic depression may have been preceded by deposition of proglacial sandy deposits (Lagoa Azul Formation; terrestrial?). Glacier displacement seems to have been controlled mainly by glacial-estuarine or attenuated fjord-like coastal inlets. The glacial lobes initially moved over highly eroded Precambrian to early Paleozoic crystalline rocks, then middle Paleozoic sedimentary rocks, and eventually over their own deposits. Multiple advance-retreat phases left a carpet of subglacial and meltwater deposits both on land and along the basin margin, although the former deposits have been almost completely eroded away. Continued, albeit less intense, tectonic subsidence of the basin led to southward displacement of the depocenter and more widespread sediment deposition. An ice cap centered on the Rio Grande do Sul shield was drained by lobes that flowed along radially distributed preglacial valleys. On the western basin margin, reduced numbers of lobes not connected to a recognizable major ice mass (or masses) seem to have moved toward the southeast. Destabilized glacigenic debris (mainly sand, diamicton, and mud) accumulated proglacially on the basin ramp and moved downslope by mass-flow processes, resulting in thick and laterally extensive packages of sand and diamicton interbedded with laminites and shales (Lagoa Azul, Campo Mourão, and Taciba Formations). Ubiquitous dropstones in laminites and in massive silty-clayey diamictons point to deposition by rain-out from sediment plumes and icebergs. Repetitive sedimentary cycles consisting of alternations between limited terrestrial facies and intraformational evidence of subglacial processes indicate that glacial conditions in the Paraná Basin persisted for 17–27 m.y. Glacial deposits are overlain by shallow-marine deltaic, coal-bearing sandstone of the Rio Bonito Formation and equivalent beds.