@article{fdi:010067654,
  title = {{M}ultistage gold mineralization in the {W}a-{L}awra greenstone belt, {NW} {G}hana : {T}he {B}epkong deposit},
  author = {{A}mponsah, {P}. {O}. and {S}alvi, {S}. and {D}idier, {B}. and {B}aratoux, {L}enka and {S}iebenaller, {L}. and {J}essell, {M}ark and {N}ude, {P}. {M}. and {G}yawu, {E}. {A}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {B}epkong gold deposit is one of several gold camps in the {P}aleoproterozoic {W}a-{L}awra greenstone belt in northwest {G}hana. {T}hese deposits lay along the {K}unche-{A}tikpi shear zone, which is part of the larger transcurrent {J}irapa shear zone. {T}he formation of these shear zones can be attributed to the general {ESE}-{WNW} major shortening that took place in the {W}a-{L}awra belt. {G}old mineralization in the {B}epkong deposit mainly occurs within graphitic shales and volcaniclastic rocks. {T}he ore consists of four {N}-{S} trending lenticular bodies, plunging steeply to the south, that are lithologically and structurally controlled. {T}heir shape and thickness are variable, though a general strike length of 560 m and an overall thickness of 300 m can be defined. {A}n alteration mineral assemblage characterises the ore, and consists of chloritecalcite-sericite-quartz-arsenopyrite-pyrite. {P}yrite, as distinct from arsenopyrite, is not limited to the altered rocks and occurs throughout the area. {A}t {B}epkong, gold is associated with arsenopyrite and pyrite, which occur disseminated in the mineralized wall rock, flanking {T}ype-1 quartz veins, or within fractures crossing these veins. {T}extural observations indicate the early formation of abundant arsenopyrite, followed by pyrite, with chalcopyrite, galena, sphalerite and pyrrhotite occurring as inclusions within pyrite and altered arsenopyrite. {D}etailed petrography, coupled with {SEM}, {LA}-{ICP}-{MS} and {EMP} analyses, indicate that gold in the {B}epkong deposit occurs in three distinct forms: (i) invisible gold, mostly in arsenopyrite (ii); visible gold as micron-size grains within fractures and altered rims of arsenopyrite, as well as at the interface of sulphide grains; (iii) free visible gold in fractures in quartz veins and their selvages. {W}e interpret the invisible gold to have co-precipitated with the early-formed arsenopyrite. {T}he small visible gold grains observed within the sulphide interfaces, altered arsenopyrite, fractures and grain boundaries, are interpreted to have formed as a result of the dissolution and redistribution of the invisible gold during later alteration of arsenopyrite, which took place at lower temperatures during crenulation and fracturing accompanying late deformation, and was accompanied by pervasive pyritization of the wall rock.},
  keywords = {{I}nvisible gold ; {G}old remobilization ; {NW} {G}hana ; {B}epkong deposit ; {P}yrite ; {A}rsenopyrite ; {F}luid inclusions ; {GHANA}},
  booktitle = {},
  journal = {{J}ournal of {A}frican {E}arth {S}ciences},
  volume = {120},
  numero = {},
  pages = {220--237},
  ISSN = {1464-343{X}},
  year = {2016},
  DOI = {10.1016/j.jafrearsci.2016.05.005},
  URL = {https://www.documentation.ird.fr/hor/fdi:010067654},
}