Early Cambrian U-Pb zircon age and Hf-isotope data from the Guasayán pluton, Sierras Pampeanas, Argentina: implications for the northwestern boundary of the Pampean arc

An Early Cambrian pluton, known as the Guasayán pluton, has been identified in the central area of Sierra de Guasayán, northwestern Argentina. A U?Pb zircon Concordia age of 533 ± 4 Ma was obtained by LA-MC-ICP-MS and represents the first report of robustly dated Early Cambrian magmatism for the northwestern Sierras Pampeanas. The pluton was emplaced in low-grade metasedimentary rocks and its magmatic assemblage consists of K-feldspar (phenocrysts) + plagioclase + quartz + biotite, with zircon, apatite, ilmenite, magnetite and monazite as accessory minerals. Geochemically, the granitic rock is a metaluminous subalkaline felsic granodiorite with SiO2 = 69.24%, Na2O+ K2O = 7.08%, CaO = 2.45%, Na2O/ K2O = 0.71 and FeO/MgO = 3.58%. Rare earth element patterns show moderate slope (LaN/YbN = 8.05) with a slightly negative Eu anomalies (Eu/Eu* = 0.76). We report the first in situ Hf isotopes data (εHft = -0.12 to -4.76) from crystallized zircons in the Early Cambrian granites of the Sierras Pampeanas, helping to constrain the magma source and enabling comparison with other Pampean granites. The Guasayán pluton might provide a link between Early Cambrian magmatism of the central Sierras Pampeanas and that of the Eastern Cordillera, contributing to define the western boundary of the Pampean paleo-arc.Fil: Dahlquist, Juan Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Verdecchia, Sebastián Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Baldo, Edgardo Gaspar Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Basei, Miguel A. S.. Universidade Do Brasilia. Instituto de Geociencias; BrasilFil: Alasino, Pablo Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Uran, Gimena Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Rapela, Carlos Washington. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: da Costa Campos Neto, Mario. Universidade de Sao Paulo; BrasilFil: Zandomeni, Priscila Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentin

The Rodeo de la Bordalesa Tonalite Dykes as a Lower Devonian Magmatic Event: Geochemical and Isotopic Age Constraints

One of the ‘pre-Carboniferous units’ from the San Rafael Block is the sedimentary Río Seco de los Castaños Formation, which is distributed in isolated outcrops within the Block. At the Rodeo de la Bordalesa area two small intrusives in the mentioned unit were mapped, composed of tonalitic rocks, lamprophyre (‘spessartite-kersantite’) and aplite dykes.We present in this paper, geochemical and isotopic data from the gray tonalitic rocks with abundant mafic enclaves and late magmatic aplite veins. The country rocks are a folded sequence of feldspathic sandstones, wackes, and shales. The Rodeo de la Bordalesa tonalite dykes are characterized by high to medium potassium concentration, with metaluminous composition and I-type calc-alkaline signature. The 401 ± 4 Ma U–Pb zircon age corresponds to the emplacement time and it is confirmed by the K–Ar biotite age. The Rb–Sr whole rocks and biotite age of 374 ± 4 Ma could be related to deformation during the ‘Chanic’ tectonic phase. Nd model ages (TDM) show an interval between 1 and 1.6 Ga, indicating Mesoproterozoic age derivation, whereas the negative εNd is typical from crustal sources. The crystallization age for the Rodeo de la Bordalesa tonalite corresponds to a Lower Devonian time and suggests that part of the Late Famatinian magmatic event is present in the San Rafael Block. The dykes are contemporaneous with the large peraluminous batholith in Pampeanas Ranges, with the transpressional shear belts during ‘Achalian’ event and could be correlated with the Devonian magmatism present in the southern part of the Frontal Cordillera. The geochemical and geochronological data allow us to differentiate the Rodeo de la Bordalesa tonalite from the mafic rocks exposed at the El Nihuil area.Facultad de Ciencias Naturales y Muse

Silurian-Devonian Land-Sea Interaction within the San Rafael Block, Argentina: Provenance of the Río Seco de los Castaños Formation

The Río Seco de los Castaños Formation (RSC) is one of the ‘pre-Carboniferous units’ outcropping within the San Rafael Block assigned to Upper Silurian–Lower Devonian age. We review the provenance data obtained by petrography and geochemical-isotope analyses as well as the U–Pb detrital zircon ages. Comparison with La Horqueta Formation is also discussed. The main components of this marine fine-grained siliciclastic platform are sandstones and mudstones. The conglomerates are restricted to channel fill deposits developed mainly at the Lomitas Negras location. A low anchizone for the RSC was indicated by illite crystallinity index. From the geochemical proxies described above (Manassero et al. in Devonian Change: Case studies in Palaeogeography and Palaeoecology. Geological Society, 2009) a provenance from an unrecycled crust with an average composition similar to depleted compared with average Upper Continental Crust is suggested. TDM ages are within the range of the Mesoproterozoic basement and Palaeozoic supracrustal rocks of the Precordillera-Cuyania terrane. εNd values of the RSC are similar to those from sedimentary rocks from the Lower Palaeozoic carbonate-siliciclastic platform of the San Rafael Block. These data suggest an Early Carboniferous (Mississipian) low-metamorphic (anchizone) event for the unit. It is correlated with the ‘Chanic’ tectonic phase that affected the Precordillera-Cuyania terrane and also linked to the collision of the Chilenia terrane in the western pre-Andean Gondwana margin. As final remarks we can comment that the studied RSC samples show dominant source derivation from Famatinian (Late Cambrian-Devonian) and Pampean-Brasiliano (Neoproterozoic-Early Cambrian) cycles. Detritus derived from the Mesoproterozoic basement are scarce. U–Pb data constrain the maximum sedimentation age of the RSC to the Silurian–Early Devonian.Centro de Investigaciones Geológica

Geochronology and geochemistry of the tabaquito batholith (Frontal cordillera, argentina): Geodynamic implications and temporal correlations in the sw gondwana margin

The Tabaquito batholith (Frontal Cordillera, western Argentina), is mainly composed of shallowly emplaced granodiorite to minor monzogranite with abundant mafic microgranular enclaves. New sensitive high-resolution ion microprobe U–Pb zircon ages of c. 337 Ma (biotite granodiorite) and c. 284 Ma (mafic dyke) along with previously published geochronological data suggest that a long-lived magmatic system formed through at least two magmatic pulses at c. 337 and c. 322 Ma with later superimposition of Permian magmatism. The Tabaquito granitoids are metaluminous, calc-alkalic and magnesian with I-type affinity. Elevated Th/Nb, Y/Nb and La/Nb ratios along with negative Nb–Ta and positive Pb anomalies are consistent with a continental arc setting. Hf, Nd and Sr isotopic composition of the Tabaquito granitoids suggests that their source could result from mixing of an old felsic crustal component and a juvenile mafic to intermediate component. New geochronological and geochemical data together with published data reveal a continuous arc setting from the Carboniferous to the Permian in Argentina, and important magmatic compositional variations through time and space controlled by episodic fluctuations in the subduction angle of the oceanic plate. Reported and compiled data allow us to infer the continuity of the Carboniferous magmatic arc along the west margin of Gondwana.Fil: Moreno Moreno, Juan Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Dahlquist, Juan Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Morales Camera, Matías Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Alasino, Pablo Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Larrovere, Mariano Alexis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Basei, Miguel A. S.. Universidade de Sao Paulo; BrasilFil: Galindo, Carmen. Universidad Complutense de Madrid; EspañaFil: Zandomeni, Priscila Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Rocher, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; Argentin

Edad U-Pb y análisis isotópico de Hf en circones del plutón Guasayán del Cámbrico temprano, Sierras Pampeanas, Argentina: implicancias para el límite noroccidental del arco pampeano

An Early Cambrian pluton, known as the Guasayán pluton, has been identified in the central area of Sierra de Guasayán, northwestern Argentina. A U-Pb zircon Concordia age of 533±4 Ma was obtained by LA-MC-ICP-MS and represents the first report of robustly dated Early Cambrian magmatism for the northwestern Sierras Pampeanas. The pluton was emplaced in low-grade metasedimentary rocks and its magmatic assemblage consists of K-feldspar (phenocrysts)+plagioclase+quartz+biotite, with zircon, apatite, ilmenite, magnetite and monazite as accessory minerals. Geochemically, the granitic rock is a metaluminous subalkaline felsic granodiorite with SiO2=69.24%, Na2O+K2O=7.08%, CaO=2.45%, Na2O/ K2O=0.71 and FeO/MgO=3.58%. Rare earth element patterns show moderate slope (LaN/YbN=8.05) with a slightly negative Eu anomalies (Eu/Eu*=0.76). We report the first in situ Hf isotopes data (εHft=-0.12 to-4.76) from crystallized zircons in the Early Cambrian granites of the Sierras Pampeanas, helping to constrain the magma source and enabling comparison with other Pampean granites. The Guasayán pluton might provide a link between Early Cambrian magmatism of the central Sierras Pampeanas and that of the Eastern Cordillera, contributing to define the western boundary of the Pampean paleo-arc.Un plutón de edad Cámbrica temprana, conocido como plutón Guasayán, ha sido identificado en el área central de la sierra de Guasayán, noroeste de Argentina. Una edad U-Pb en concordia de 533±4 Ma fue obtenida en circones mediante LA-MC-ICP-MS. Esta edad representa el primer reporte de magmatismo Cámbrico temprano para el noroeste de las Sierras Pampeanas. El mismo está emplazado en rocas metasedimentarias de bajo grado y se caracteriza por una asociación magmática de K-feldespato fenocristales)+plagioclasa+cuarzo+biotita, con circón, apatita, ilmenita, magnetita y monacita como minerales accesorios. Geoquímicamente, la roca granítica se clasifica como una granodiorita félsica metaluminosa subalcalina con contenidos de SiO2=69,24%, Na2O+K2O=7,08%, CaO=2,45% y relaciones de Na2O/K2O=0,71 y FeO/MgO=3,58%. Los patrones de elementos de tierras rara muestran una pendiente moderada (LaN/YbN=8,05) con una ligera anomalía negativa de Eu (Eu/Eu*=0,76). Nosotros reportamos los primeros datos in situ de isótopos de Hf (εHft=-0,12 a -4,76) para circones cristalizados en granitos del Cámbrico temprano de Sierras Pampeanas, lo que aporta información crítica sobre la fuente de los magmas, permitiendo la comparación con otros granitos pampeanos. El plutón Guasayán podría proveer el enlace entre el magmatismo del Cámbrico temprano del sector central de las Sierras Pampeanas y aquel de la cordillera Oriental, contribuyendio a definir el límite occidental del paleoarco Pampeano.Facultad de Ciencias Naturales y MuseoCentro de Investigaciones Geológica

The Mesoproterozoic Basement at the San Rafael Block, Mendoza Province (Argentina): Geochemical and Isotopic Age Constraints

This work provides new petro-geochemical and isotopic information to constrain the crustal evolution of the Precambrian Cerro La Ventana Formation. The Rb–Sr, Sm–Nd, Pb–Pb, and U–Pb isotopic data obtained as well as their petrological and geochemical features are reported. These data are useful to discuss relationships with equivalent Mesoproterozoic units located along the Cuyania terrane in the proto-Andean Gondwana margin. The type section of the basement rocks of the Cerro La Ventana Formation is located in the south-eastern part of the San Rafael Block, Mendoza Province known as Leones-Ponón Trehué-La Estrechura region. Equivalent crustal fragments are also included in this basement, such as ductile-deformed rocks of the El Nihuil Mafic Unit that are intruded by Ordovician undeformed dolerites. The basement exposed along the type section corresponds to a metamorphosed volcano-plutonic complex with hardly any sedimentary protolith. Main rocks are tonalites and foliated gabbros and quartz diorites that pass to amphibolites, and minor granodioritic–dioritic orthogneisses, with abundant angular microgranitoid enclaves now deformed and stretched intruded in mafic to felsic metavolcanics with porphyritic relic textures. The studied samples classified as tonalites and some close to the field of granodiorites following a calc-alkaline trend. Gabbroic samples from the El Nihuil mafic unit show a more tholeiitic signature. The bulk of samples from the Cerro La Ventana Formation plot within the field of metaluminous rocks; although a few are in the peraluminous field. Main groups of samples plot as low-Al TTD field; however, some of them show high Sr/Y ratios which are typical of high-Al TTD. The Mg#/K ratio is higher in the Cerro La Ventana Formation compared with Las Matras TTG series suggesting a minor differentiated grade for the first one. The chondrite-normalized REE diagrams for Leones samples have Eu anomalies rather positive and gabbros from El Nihuil region display patterns with positive Eu anomalies typical of plagioclase-rich igneous rocks. The Rb–Sr data defined an isochron with 1148 ± 83 Ma, initial 87Sr/86Sr = 0.70292 ± 0.00018. The low initial ratio is indicative of a slight evolved Mesoproterozoic source. An acceptable isochron was obtained using Sm–Nd methodology indicating an age of 1228 ± 63 Ma. The model ages (TDM) are in the range 1.23–1.64 Ga with εNd(1200) in between −0.94 and +4.7 recording a ‘depleted’ source, less evolved than CHUR for the time of crystallization. In a 207Pb/204Pb diagram the samples plot similarly to rocks from the basement of Cuyania Terrane (Pie de Palo Range and crustal xenoliths) showing a distinctive non-radiogenic signature. The tonalitic lithofacies located at the Leones River type section was chosen for zircon U–Pb TIMS dating and the obtained crystallization age was 1214.7 ± 6.5 Ma. The in situ U–Pb (LA-ICP-MS) zircon data done in two different laboratories on samples from El Nihuil mafic unit (tonalitic orthogneisses) plotted in a Concordia diagram, record an intercept at 1256 ± 10 Ma and in Tera-Wasserburg diagram an age of 1222 ± 6.9 Ma. With these isotopic data we confirm the Mesoproterozoic age for the basement of the San Rafael Block. The obtained ca. 1.2 Ga is quite similar to those belonging to the basement of other regions from the Cuyania allochthonous terrane.Centro de Investigaciones Geológica

Geology and petrogenetic considerations of the Loma Marcelo skarn, Neoproterozoic basement of the Ventania System, Argentina

The Late Precambrian–Early Palaeozoic crystalline basement of the Ventania System is mainly composed of Neoproterozoic S-type granites, Early Cambrian alkaline granites, and Middle Cambrian peralkaline rhyolites. The Neoproterozoic granites (ca. 607–581 Ma) crop out in the Cerro Pan de Azúcar-Cerro del Corral area and host the Loma Marcelo Ca/Mg skarn, composed of calc-silicate- and chondrodite-bearing assemblages. Petrographical, geochemical, and geochronological data indicate that the skarn was formed from carbonate xenoliths of sedimentary nature incorporated during the intrusion of the Neoproterozoic granites and that it is the result of three successive metamorphic events. The first one is related to the incorporation of carbonate xenoliths by the intrusion and the associated contact metamorphism. The second event is linked to the crystallization of the Early Cambrian granites and related post-magmatic processes. They are responsible for fluorine influx into the Neoproterozoic basement, which resulted in the formation of high-F minerals in the Loma Marcelo skarn (e.g. vesuvianite, chondrodite). The Sm-Nd garnet-whole rock isochron age of 526.8 ± 12.0 Ma in the skarn confirms its relationship with the Early Cambrian magmatism. The last event corresponds to a regional metamorphism assigned to the Late Devonian–Early Carboniferous on the basis of a LA-ICP-MS U-Pb age of 353.4 ± 6.7 Ma determined on zircons of the skarn as well as a Rb-Sr quartz-sericite isochron age of 364.4 ± 3.6 Ma obtained from a quartz vein that post-tectonically cuts the already mylonitized granites. The different chemical compositions of the carbonate protoliths determined the formation of two types of skarns of calcic and magnesian compositions. A single date of the calcic skarn defined a LA-ICP-MS U-Pb upper intercept age of 648 ± 21 Ma, providing the maximum sedimentation age for the calcic protolith of the Loma Marcelo skarn. The minimum sedimentation age is provided by the crystallization age of the S-type granite surrounding the skarn (ca. 607 Ma). The Loma Marcelo skarn reveals the occurrence of underground Neoproterozoic carbonate (meta-?) sedimentary rocks as part of the basement of the Ventania System. These rocks could correlate with the carbonate sequences of the neighbouring Claromecó Basin and Tandilia System.Facultad de Ciencias Naturales y MuseoInstituto de Recursos MineralesCentro de Investigaciones Geológica

Detrital zircon ages from Archaean conglomerates in the Singhbhum Craton, eastern India: implications on economic Au-U potential

New U–Pb age and Hf isotope data obtained on detrital zircon grains from Au- and U-bearing Archaean quartz-pebble conglomerates in the Singhbhum Craton, eastern India, specifically the Upper Iron Ore Group in the Badampahar Greenstone Belt and the Phuljhari Formation below the Dhanjori Group provide insights into the zircon provenance and maximum age of sediment deposition. The most concordant, least disturbed $^{207}$Pb/$^{206}$Pb ages cover the entire range of known magmatic and higher grade metamorphic events in the craton from 3.48 to 3.06 Ga and show a broad maximum between 3.38 and 3.18 Ga. This overlap is also mimicked by Lu–Hf isotope analyses, which returned a wide range in $_{εHf}$(t) values from + 6 to − 5, in agreement with the range known from zircon grains in igneous and metamorphic rocks in the Singhbhum Craton. A smaller but distinct age peak centred at 3.06 Ga corresponds to the age of the last major magmatic intrusive event, the emplacement of the Mayurbhanj Granite and associated gabbro, picrite and anorthosite. Thus, these intrusive rocks must form a basement rather than being intrusive into the studied conglomerates as previously interpreted. The corresponding detrital zircon grains all have a subchondritic Hf isotopic composition. The youngest reliable zircon ages of 3.03 Ga in the case of the basal Upper Iron Ore Group in the east of the craton and 3.00 Ga for the Phuljhari Formation set an upper limit on the age of conglomerate sedimentation. Previously published detrital zircon age data from similarly Au-bearing conglomerates in the Mahagiri Quartzite in the Upper Iron Ore Group in the south of the craton gave a somewhat younger maximum age of sedimentation of 2.91 Ga. There, the lower limit on sedimentation is given by an intrusive relationship with a c. 2.8 Ga granite. The time window thus defined for conglomerate deposition on the Singhbhum Craton is almost identical to the age span established for the, in places, Au- and U-rich conglomerates in the Kaapvaal Craton of South Africa: the 2.98–2.78 Ga Dominion Group and Witwatersrand Supergroup in South Africa. Since the recognition of first major concentration of gold on Earth’s surface by microbial activity having taken place at around 2.9 Ga, independent of the nature of the hinterland, the above similarity in age substantially increases the potential for discovering Witwatersrand-type gold and/or uranium deposits on the Singhbhum Craton. Further age constraints are needed there, however, to distinguish between supposedly less fertile (with respect to Au) > 2.9 Ga and more fertile < 2.9 Ga successions