Remobilisation features and structural control on ore grade distribution at the Konkola stratiform Cu–Co ore deposit, Zambia

Torremans, Koen; Gauquie, Johanna; Boyce, Adrian J.; Barrie, Craig D.; Dewaele, Stijn; Sikazwe, O.; Muchez, Philippe

doi:10.1016/j.jafrearsci.2012.10.005

Cited by 29 publications

(20 citation statements)

References 72 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several other deposits in the Central African Copperbelt contain pre-folding bedding-parallel veins with fibrous growth morphology (Mendelsohn, 1961b;Sweeney et al, 1986;Annels, 1989;Selley et al, 2005;McGowan et al, 2006;Sillitoe et al, 2010;Hitzman et al, 2012;Schuh et al, 2012;Torremans et al, 2013), although not all of these deposits reveal the exact same fine-grained carbonaceous argillite facies as in this study. Hence, if the pre-folding veins are present in these deposits, similar mechanisms could be at work.…”

Section: Enhanced Permeability Structures: Implications For Fluid Flosupporting

confidence: 51%

Mechanisms of flexural flow folding of competent single-layers as evidenced by folded fibrous dolomite veins

Torremans

Muchez

Sintubin

2014

Journal of Structural Geology

View full text Add to dashboard Cite

a b s t r a c tFlexural flow is thought unlikely to occur in naturally deformed, competent isotropic single-layers. In this study we discuss a particular case of folded bedding-parallel fibrous dolomite veins in shale, in which the internal strain pattern and microstructural deformation features provide new insights in the mechanisms enabling flexural flow folding. Strain in the pre-folding veins is accommodated by two main mechanisms: intracrystalline deformation by bending and intergranular deformation with bookshelf rotation of dolomite fibres. The initially orthogonal dolomite fibres allowed a reconstruction of the strain distribution across the folded veins. This analysis shows that the planar mechanical anisotropy created by the fibres causes the veins to approximate flexural flow. During folding, synkinematic veins overgrow the pre-folding fibrous dolomite veins. Microstructures and dolomite growth morphologies reflect growth during progressive fold evolution, with evidence for flexural slip at fold lock-up. Homogeneous flattening, as evidenced by disjunctive axial-planar cleavage, subsequently modified these folds from class 1B to 1C folds. Our study shows that the internal vein fabric has a first-order influence on folding kinematics. Moreover, the fibrous dolomite veins show high viscosity contrasts with the shale matrix, essential in creating transient permeability for subsequent mineralising stages in the later synkinematic veins during progressive folding.

show abstract

Section: Enhanced Permeability Structures: Implications For Fluid Flosupporting

confidence: 51%

Mechanisms of flexural flow folding of competent single-layers as evidenced by folded fibrous dolomite veins

Torremans

Muchez

Sintubin

2014

Journal of Structural Geology

View full text Add to dashboard Cite

show abstract

“…The presence of mineralized stylolites connected to mineralized sedimentary beds (Figure 10(b)) indicates that the vein mineralization in Tizert could be related to local remobilization, during compressional tectonics, of earlier sulphides rather than a separate mineralization generated by hydrothermal fluid circulation. Copper (re)mobilization has been documented in numerous sediment-hosted copper deposits [76][77][78][79][80]. At least two Cu-Co sulphide phases, diagenetic and synorogenic, are present in the Katanga Copperbelt [78].…”

Section: Timing Of Mineralization and Genetic Processesmentioning

confidence: 99%

Geology and Metallogenesis of the Sediment-Hosted Cu-Ag Deposit of Tizert (Igherm Inlier, Anti-Atlas Copperbelt, Morocco)

et al. 2017

View full text Add to dashboard Cite

The Tizert Cu-Ag deposit is the largest of a series of sediment-hosted copper deposits of the Anti-Atlas copper province in Morocco. Mineralized rocks in the deposit contain disseminated sulphides within a Late Ediacaran, dominantly siliciclastic sedimentary formation named the Basal Series. Isopach map of the Basal Series thickness shows that during the Late Ediacaran the area was composed of large subsiding zones separated by paleohighs. The ore-grade zones are well developed along basin margins adjacent to the basement paleohighs. These mineralized zones display a lateral sulphide zoning with central bornite-chalcocite zones grading outward to intermediate chalcopyrite and external pyrite zones. There is also a vertical sulphide zoning with evolution from bornite and chalcocite dominant mineralized rocks at the bottom to chalcopyrite and pyrite dominant mineralized rocks at the top of the lithostratigraphic succession. A second style of mineralization is represented by sulphide filled fractures and veins present in the Basal Series, as well as in the basement and the overlying dolomites. The similarity of the paragenetic sequences between the disseminated and the vein-hosted mineralization suggests that they may be related to the same mineralizing event, the disseminated style of mineralization being rapidly followed by the onset of the vein-style mineralization.

show abstract

“…Minor ore also occurs at the top of the underlying Mindola Clastics Fm and at the base of hanging wall units overlying it. Mineralisation occurs as disseminated sulfides in the host rock, in several generations of veins and associated with structures such as hinge zones of tight-to-isoclinal folds, deformed veins, faults, and burial or tectonic foliations (Brems et al, 2009;Torremans et al, 2014). Several mineralisation/remobilisation stages have been identified at Nkana (Brems et al, 2009;Muchez et al, 2010).…”

Section: The Chambishi-nkana Basin and Nkanamentioning

confidence: 99%

“…addition to disseminated and lenticular ore (for location see Fig. 2;Brems et al, 2009;Croaker, 2011;Torremans et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

“…Unequivocal evidence for early diagenetic Cu-Co mineralisation is lacking, which does not preclude its existence (Brems et al, 2009;Muchez et al, 2010). At Nkana South, several mineralisation/remobilisation stages have been identified from basin inversion onwards, characterised by different vein generations that formed during compressional deformation (Muchez et al, 2010;Torremans et al, 2014). Geological mapping has indicated that rich orebodies are present in the hinge zones of tight-to-isoclinal folds, both at Nkana South (Brems et al, 2009) and Nkana Central (De Cleyn, 2009).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Non-cylindrical parasitic folding and strain partitioning during the Pan-African Lufilian orogeny in the Chambishi–Nkana Basin, Central African Copperbelt

Torremans¹,

Muchez²,

Sintubin³

2018

Solid Earth

View full text Add to dashboard Cite

Abstract. A structural analysis has been carried out along the south-east margin of the Chambishi–Nkana Basin in the Central African Copperbelt, hosting the world-class copper and cobalt (Cu–Co) Nkana orebody. The geometrically complex structural architecture is interpreted to have been generated during a single NE–SW-oriented compressional event, clearly linked to the Pan-African Lufilian orogeny. This progressive deformation resulted primarily in asymmetric multiscale parasitic fold assemblages, characterised by non-cylindrical NW–SE-oriented periclinal folds that strongly interfere laterally, leading to fold linkage and bifurcation. The vergence and amplitude of these folds consistently reflect their position along an inclined limb of a NW-plunging megascale first-order fold. A clear relation is observed between the intensity of parasitic folding and the degree of shale content in the Copperbelt Orebody Member (COM), which hosts most of the ore. Differences in fold amplitude, wavelength and shape are explained by changes in mechanical stratigraphy caused by lateral lithofacies variation in ore-bearing horizons. In addition, strong differences in strain partitioning occur within the deforming basin, which is interpreted to be in part controlled by changes in mechanical anisotropy in the layered rock package. This work provides an essential backdrop to understand the influence of the Lufilian orogeny on metal mineralisation and (re-)mobilisation in the Copperbelt.

show abstract

Remobilisation features and structural control on ore grade distribution at the Konkola stratiform Cu–Co ore deposit, Zambia

Cited by 29 publications

References 72 publications

Mechanisms of flexural flow folding of competent single-layers as evidenced by folded fibrous dolomite veins

Mechanisms of flexural flow folding of competent single-layers as evidenced by folded fibrous dolomite veins

Geology and Metallogenesis of the Sediment-Hosted Cu-Ag Deposit of Tizert (Igherm Inlier, Anti-Atlas Copperbelt, Morocco)

Non-cylindrical parasitic folding and strain partitioning during the Pan-African Lufilian orogeny in the Chambishi–Nkana Basin, Central African Copperbelt

Contact Info

Product

Resources

About