The petrographical and geochemical analyses of greywacke and siltstone samples from the Nampala gold deposit of the Paleoproterozoic Birimian supergroup, Southern Mali, have been carried out to make inferences on the provenance, tectonic settings, and weathering history of the sediments. Petrographical investigations revealed that greywackes can be classified as feldspathic wackes, with immature to moderately mature sediments, with the siltstones being immature. Geochemically, greywackes show features that resemble typical wacke sedimentary rocks, whereas the siltstones are arkose to litharenite. Overall, Nampala sedimentary rocks experienced low intensity of paleoweathering with <70 CIA and <90 CIW values and have not undergone significant sediment recycling having >1 CIV values. Their quartz and feldspar contents, together with the ratio of Al2O3/TiO2 and La/Sc, suggest the derivation of sediments from felsic igneous rocks, with a possible minor contribution from mafic proto-source rock. The petrographic and geochemical features of the greywackes and siltstones are consistent with siliciclastic rocks formed in an active continental margin, similar to other sedimentary rocks of the Paleoproterozoic Birimian terrane. These findings put positive constraints on the subduction-accretion geodynamic model proposed for the evolution of the Birimian terrane of the West African Craton.
DickinsonWR. Provenance and sediment dispersal in relation to paleotectonics and paleogeography of sedimentary basins. In: New perspectives in basin analysis. NY: Springer New York, 1988, pp.3–25.
2.
CullersRL. The controls on the major and trace element variation of shales, siltstones, and sandstones of Pennsylvanian-Permian age from uplifted continental blocks in Colorado to platform sediment in Kansas, USA. Geochimica et Cosmochimica Acta1994; 58: 4955–4972.
3.
AnaniCYMahamudaAKwayisiD,et al.Provenance of sandstones from the neoproterozoic Bombouaka group of the volta basin, Northeastern Ghana. Arabian J Geosci2017; 10: 1–15. doi:https://doi.org/10.1007/s12517-017-3243-2
4.
AnaniCYBonsuSKwayisiD,et al.Geochemistry and provenance of neoproterozoic metasedimentary rocks from the Togo structural unit, southeastern Ghana. J Afr Earth Sci2019; 153: 208–218.
5.
KwayisiDLehmannJElburgM. Provenance and depositional setting of the Buem structural unit (Ghana): implications for the paleogeographic reconstruction of the West African and Amazonian cratons in Rodinia. Gondwana Res2022b; 109: 183–204.
6.
KazapoeRWOkunlolaOArhinE, et al.Compositional characteristics of mineralised and unmineralised gneisses and schist around the Abansuoso area, southwestern Ghana. Appl Earth Sci2023; 132: 36–51.
7.
DickinsonWR. Interpreting provenance relations from detrital modes of sandstones. In: Provenance of arenites. Springer Netherlands, 1985, pp.333–361.
8.
BhatiaMRTaylorSR. Trace-element geochemistry and sedimentary provinces: a study from the Tasman Geosyncline, Australia. Chem Geol1981; 33: 115–125.
9.
McLennanSM. Rare earth elements in sedimentary rocks: influence of provenance and sedimentary processes. Geochem Mineral Rare Earth Elements Rev Miner1989; 21: 169–200.
10.
JessellMSantoulJBaratouxL, et al.An updated map of West African mafic dykes. J Afr Earth Sci2015; 112: 440–450.
11.
SakyiPASuBXManuJ, et al.Origin and tectonic significance of the metavolcanic rocks and mafic enclaves from the Palaeoproterozoic Birimian Terrane, SE West African Craton, Ghana. Geol Mag2020; 157: 1349–1366.
12.
AtangaFAmponsahPONunooS, et al.The geology and geochemistry of the Rhyacian Josephine gold deposit, Northwest Ghana. Appl Earth Sci2023; 132: 252–270.
13.
AmponsahPOKwayisiDAwunyoEK, et al.New evidence for crustal reworking and juvenile arc-magmatism during the Palaeoproterozoic Eburnean events in the Suhum Basin, South-East Ghana. Geol J2023; 58: 3734–3755.
14.
MilésiJPLedruPFeybesseJL, et al.Early Proterozoic ore deposits and tectonics of the Birimian orogenic belt, West Africa. Precambrian Res1992; 58: 305–344.
15.
TshibubudzeAHeinKAAPetersLFH, et al.Oldest U-Pb crystallisation age for the West African craton from the Oudalan-Gorouol Belt of Burkina Faso. South Afr J Geol2013; 116: 169–181.
16.
KouamelanANDjroSCAllialyME, et al. The oldest rock of Ivory Coast. J Afr Earth Sci2015; 103: 65–70.
17.
RollinsonH. Archaean crustal evolution in West Africa: a new synthesis of the Archaean geology in Sierra Leone, Liberia, Guinea and Ivory Coast. Precambrian Res2016; 281: 1–12.
18.
AnumSSakyiPASuB-X, et al. Geochemistry and geochronology of granitoids in the Kibi-Asamankese area of the Kibi-Winneba volcanic belt, southern Ghana. J Afr Earth Sci2015; 102: 166–179.
19.
AgraNAElburgMAVorsterC. Constraints on Paleoproterozoic crustal growth from Birimian Supergroup lavas of the Bui belt (Ghana) in the West African Craton. Precambrian Res2023; 384: 106926.
20.
VilleneuveMCornéeJJ. Structure, evolution and palaeogeography of theWest African craton and bordering belts during the Neoproterozoic. Precambrian Res1994; 69: 307–326.
21.
EnnihNLiégeoisJP. The boundaries of the West African craton, with aspecial reference to the basement of the Moroccan metacratonic Anti-Atlas belt. In: EnnihNLiégeoisJP (eds) The boundaries of the West African craton. Geol. Soc. Lond. Spec Publ, 2008, vol. 297, pp.1–17.
22.
KwayisiDElburgMLehmannJ. Preserved ancient oceanic lithosphere within the Buem structural unit at the eastern margin of the West African craton. Lithos2022; 410: 106585.
23.
KwayisiDNyavorEDzikunooEA, et al.Cryogenian-Ediacaran crustal growth and evolution of the active margin of the Dahomeyide belt, Ghana. Geol Mag2023; 160: 1914–1931.
24.
TraoréYDSiebenallerLSalviS, et al.Progressive gold mineralization along the Syama corridor, Southern Mali (West Africa). Ore Geol Rev2016; 78: 586–598.
25.
Girard, P., Goulet, N. & Malo, M., 1998. La géologie du Mali. Projet Assistance Technique au Secteur Minier du Mali. Crédit IDA 2390-MLI. Rapp. DNGM, Bamako, Mali, n°5951, 108p.
26.
BalloIHeinAAKGuindoB, et al. The Syama and Tabakoroni goldfields, Mali. Ore Geol Rev2016; 78: 578–585.
27.
BentleyPNVenterLMoolmanR, et al.Geological review, gold target prioritisation and recommendations for future exploration work. Syama Exploration Permits Randgold Resources Ltd. internal report, unpublished. 2000.
28.
Kerr-GillespieFKinnanECarrierA. NI 43-101 Technical report for the Nampala and Mininko permits (Mali) and mineral resource estimate for the Nampala gold mine. Robex Resources Inc. 2018, p.169.
29.
MarchandJ. Form 43-101F1 technical evaluation report. Robex Resources Inc. 2012, p.50.
30.
PettijohnFJPotterPESieverR, et al.Introduction and source materials. Sand Sandstone1987; 2: 1–21.
31.
PettijohnFJPotterPESieverR. Sand and sandstone. Springer, 1972, pp.618.
32.
BhatiaMR. Plate tectonics and geochemical composition of sandstones. J Geol1983; 91: 611–627.
33.
BhatiaMRCrookKA. Trace element characteristics of graywackes and tectonic setting discrimination of sedimentary basins. Contrib Mineral Petrol1986; 92: 181–193.
34.
CrichtonJGCondieKC. Trace elements as source indicators in cratonic sediments: a case study from the early proterozoic libby creek group, southeastern Wyoming. J Geol1993; 101: 319–332.
35.
RudnickRLGaoS. Composition of the continental crust. The Crust2003; 3: 1–64.
36.
TaylorSRMcLennanSM. The continental crust: its composition and evolution. Blackwell Scientific Publ, 1985.
37.
JiangYDSchulmannKKrönerA, et al.Neoproterozoic-early Paleozoic peri-Pacific accretionary evolution of the Mongolian collage system: insights from geochemical and U-pb zircon data from the ordovician sedimentary wedge in the Mongolian Altai. Tectonics2017; 36: 2305–2331.
38.
McLennanSM. Weathering and global denudation. J Geol1993; 101: 295–303.
39.
McLennanSMHemmingSMcDanielDK,et al.Geochemical approaches to sedimentation, provenance, and tectonics. Special Papers-Geol Soc Am1993; 284: 21.
40.
NagarajanRMadhavarajuJNagendraR, et al.Geochemistry of Neoproterozoic shales of the Rabanpalli Formation, Bhima Basin, Northern Karnataka, Southern India: implications for provenance and paleoredox conditions. Revista mexicana de Ciencias Geológicas2007; 24: 150–160.
41.
MadhavarajuJLeeYI. Influence of Deccan volcanism in the sedimentary rocks of Late Maastrichtian–Danian age of Cauvery basin Southeastern India: constraints from geochemistry. Current Sci2010; 98: 528–537.
42.
FedoCMWayne NesbittHYoungGM. Unraveling the effects of potassium metasomatism in sedimentary rocks and paleosols, with implications for paleoweathering conditions and provenance. Geology1995; 23: 921–924.
43.
McLennanSMTaylorSR. Sedimentary rocks and crustal evolution: tectonic setting and secular trends. J Geol1991; 99: 1–21.
44.
GirtyGHHansonADKnaackC,et al.Provenance determined by REE, Th, and Sc analyses of metasedimentary rocks, Boyden Cave roof pendant, central Sierra Nevada, California. J Sedimentary Res1994; 64: 68–73.
45.
YangHKyserKAnsdellK. Geochemical and appendix A. Locations and mineralogical assemblages of the analysed samples Nd isotopic compositions of the metasedimentary rocks in the La Ronge Domain, Trans-Hudson Orogen, Canada: implications for the evolution of the domain. Precambrian Res1998; 92: 37–64.
46.
GarzantiEResentiniAVezzoliG, et al.Forward compositional modelling of Alpine orogenic sediments. Sedimentary Geol2012; 280: 149–164.
47.
AndersonJBWallaceDJSimmsAR, et al.Recycling sediments between source and sink during a eustatic cycle: systems of late Quaternary northwestern Gulf of Mexico basin. Earth-Sci Rev2016; 153: 111–138.
48.
DabardMP. Lower Brioverian formations (Upper Proterozoic) of the Armorican Massif (France): geodynamic evolution of source areas revealed by sandstone petrography and geochemistry. Sedimentary Geol1990; 69: 45–58.
49.
Armstrong-AltrinJS. Provenance of sands from cazones, acapulco, and bahía kino beaches, México. Revista mexicana de Ciencias Geológicas2009; 26: 764–782.
50.
Armstrong-AltrinJS. Evaluation of two multidimensional discrimination diagrams from beach and deep-sea sediments from the Gulf of Mexico and their application to Precambrian clastic sedimentary rocks. Int Geol Rev2015; 57: 1446–1461.
51.
CoxRLoweDR. A conceptual review of regional-scale controls on the composition of clastic sediment and the co-evolution of continental blocks and their sedimentary cover. J Sedimentary Res1995; 65: 1–12.
52.
MongelliGCritelliSPerriF, et al.Sedimentary recycling, provenance and paleoweathering from chemistry and mineralogy of Mesozoic continental redbed mudrocks, Peloritani Mountains, Southern Italy. Geochem J2006; 40: 197–209.
53.
NesbittHYoungGM. Early proterozoic climates and plate motions inferred from major element chemistry of lutites. nature1982; 299: 715–717.
54.
HarnoisL. The CIW index: a new chemical index of weathering. Sedimentary Geol1988; 55: 319–322.
55.
HayashiKIFujisawaHHollandHD,et al.Geochemistry of∼ 1.9 Ga sedimentary rocks from northeastern Labrador, Canada. Geochimica et Cosmochimica Acta1997; 61: 4115–4137.
56.
RoserBPKorschRJ. Provenance signatures of sandstone-mudstone suites determined using discriminant function analysis of major-element data. Chem Geol1988; 67: 119–139.
57.
FloydPALeveridgeBE. Tectonic environment of the Devonian Gramscatho basin, south Cornwall: framework mode and geochemical evidence from turbiditic sandstones. J Geol Soc1987; 144: 531–542.
58.
CullersRL. The controls on the major-and trace-element evolution of shales, siltstones and sandstones of Ordovician to Tertiary age in the Wet Mountains region, Colorado, USA. Chemical Geology1995; 123: 107–131.
59.
CondieKC. Chemical composition and evolution of the upper continental crust: contrasting results from surface samples and shales. Chem Geol1993; 104: 1–37.
60.
NanceWBTaylorSR. Rare earth element patterns and crustal evolution—II. Archean sedimentary rocks from Kalgoorlie, Australia. Geochimica et Cosmochimica Acta1977; 41: 225–231.
61.
CullersRLPodkovyrovVN. Geochemistry of the Mesoproterozoic Lakhanda shales in southeastern Yakutia, Russia: implications for mineralogical and provenance control, and recycling. Precambrian Res2000; 104: 77–93.
62.
CullersRLBasuASuttnerLJ. Geochemical signature of provenance in sand-size material in soils and stream sediments near the Tobacco Root batholith, Montana, USA. Chem Geol1988; 70: 335–348.
63.
CullersRL. Implications of elemental concentrations for provenance, redox conditions, and metamorphic studies of shales and limestones near Pueblo, CO, USA. Chem Geol2002; 191: 305–327.
64.
FengRKerrichR. Geochemistry of fine-grained clastic sediments in the Archean Abitibi greenstone belt, Canada: implications for provenance and tectonic setting. Geochimica et Cosmochimica Acta1990; 54: 1061–1081.
65.
VermaSPArmstrong-AltrinJS. Geochemical discrimination of siliciclastic sediments from active and passive margin settings. Sedimentary Geol2016; 332: 1–12.
66.
RoserBPKorschRJ. Determination of tectonic setting of sandstone-mudstone suites using SiO2 content and K2O/Na2O ratio. J Geol1986; 94: 635–650.
67.
VermaSPArmstrong-AltrinJS. New multi-dimensional diagrams for tectonic discrimination of siliciclastic sediments and their application to Precambrian basins. Chem Geol2013; 355: 117–133.
68.
BhatiaMR. Rare earth element geochemistry of Australian Paleozoic graywackes and mudrocks: provenance and tectonic control. Sedimentary Geol1985; 45: 97–113.
69.
DostalJKeppieJD. Geochemistry of low-grade clastic rocks in the Acatlán Complex of Southern Mexico: evidence for local provenance in felsic–intermediate igneous rocks. Sedimentary Geol2009; 222: 241–253.
70.
Armstrong-AltrinJSVermaSP. Critical evaluation of six tectonic setting discrimination diagrams using geochemical data of Neogene sediments from known tectonic settings. Sedimentary Geol2005; 177: 115–129.
71.
CondieKC. Another look at rare earth elements in shales. Geochimica et Cosmochimica Acta1991; 55: 2527–2531.
72.
McFarlaneHBAilleresLBettsP, et al.Episodic collisional orogenesis and lower crust exhumation during the Palaeoproterozoic Eburnean Orogeny: evidence from the Sefwi Greenstone Belt, West African craton. Precambrian Res2019; 325: 88–110.
73.
DampareSBShibataTAsieduDK, et al. Geochemistry of Paleoproterozoic metavolcanic rocks from the southern Ashanti volcanic belt, Ghana: Petrogenetic and tectonic setting implications. Precambrian Res2008; 162: 403–423.
74.
SenyahGADampareSBAsieduDK. Geochemistry and tectonic setting of the Paleoproterozoic metavolcanic rocks from the Chirano Gold District, belt, Ghana. J Afr Earth Sci2016; 122: 32–46.
75.
SakyiPAManuJSuBX, et al. Geochemical and Sm-Nd isotopic evidence for the composition of the Palaeoproterozoic crust of the West African Craton in Ghana. Geol J2019; 54: 3940–3957.
76.
SakyiPASuBXAnumS, et al. New zircon U-Pb ages for erratic emplacement of 2213-2130 Ma Paleoproterozoic calc-alkaline I-type granitoid rocks in the Lawra Volcanic Belt of Northwestern Ghana. West Africa. Precambrian Res2014; 254: 149–168.
77.
LeubeAHirdesWMauerR,et al.The Early Proterozoic Birimian Supergroup of Ghana and some aspects of its associated gold mineralization. Precambrian Res1990; 46: 139–165.
78.
RoddazMDebatPNikiémaS. Geochemistry of upper Birimian sediments (major and trace elements and Nd–Sr isotopes) and implications for weathering and tectonic setting of the Late Paleoproterozoic crust. Precambrian Res2007; 159: 197–211.
79.
ManuJAsieduDKAnaniCY. Geochemistry of Birimian phyllites from the Obuasi and Prestea mines, Southwestern Ghana: implications for provenance and source-area weathering. Int J Basic Appl Sci2013; 2: 12.
80.
AsieduDKAsongSAtta-PetersD, et al.Geochemical and Nd-isotopic compositions of juvenile-type paleoproterozoic Birimian sedimentary rocks from southeastern West African craton (Ghana): constraints on provenance and tectonic setting. Precambrian Res2017; 300: 40–52.
81.
AsieduDKAgoeMAmponsahPO, et al.Geochemical constraints on provenance and source area weathering of metasedimentary rocks from the Paleoproterozoic (∼ 2.1 Ga) Wa-Lawra Belt, southeastern margin of the West African Craton. Geodinamica Acta2019; 31: 27–39.
82.
BrakoBAAmaduCCFoliG, et al.Petrography and geochemistry of metasedimentary rocks from the Paleoproterozoic Birimian at the Chagupana area, North-West Ghana: implications for provenance and tectonic setting. Arab J Geosci2022; 15: 1749.
