ARTICLE Fluid pressure–dominated orogenic gold mineralization under low differential stress: case of the Yaouré gold camp, Côte d’Ivoire, West Africa Nicolas Mériaud 1 & Quentin Masurel 1 & Nicolas Thébaud 1 & Ghislain Tourigny 2 Received: 19 December 2018 / Accepted: 24 September 2019 # Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract The ~ 1.5 Moz Yaouré gold deposit, which is located within the Birimian greenstone belts of central Côte d’Ivoire (West Africa), is associated with two stages of economic gold mineralization. Both ore-forming stages occurred during protracted E-W-directed shortening associated with the Eburnean orogeny. The first mineralization stage is hosted by fault-fill veins along conjugate ENE- striking (dextral) and WNW-striking (sinistral) strike-slip fault arrays. This ore stage is associated with a polymetallic assemblage including Mo, Bi, Pb, W, Te, Ag, and Au and cryptic alteration in wall rocks. The second and main gold mineralization stage is associated with a low-displacement fault-fracture-vein mesh formed during a reverse faulting episode. This second gold phase is associated with a polymetallic assemblage including W and Au ± Pb and is characterized by pronounced albite-ankerite-pyrite hydrothermal alteration in wall rocks. Shear veins associated with this second mineralization episode formed during episodic fluid pressure variations under low differential stress within pre-existing low-angle reverse fault planes. Permeability destruction by albite-ankerite-pyrite hydrothermal sealing of these low-angle reverse faults resulted in fluid pressure build-up and ultimately in the development of extension veins under low differential stress in the late stages of the structural evolution of the deposit. This study presents the structural evolution of a polyphase orogenic gold deposit and highlights that the interplay between fault zone activity, hydrothermal alteration, and fluid pressure fluctuations at low differential and deviatoric stresses were key in controlling fluid flow and the formation of ore within optimally-oriented faults. Keywords West Africa . Orogenic gold . Vein-hosted . Differential stress . Transient stress switches Introduction The location and geometry of orogenic gold deposits are depen- dent on the crustal architecture, which controls fluid circulation and gold precipitation (Kerrich 1986; Ridley 1993; Wyman and Kerrich 1988; Goldfarb et al. 1991b; McCuaig and Hronsky 2014). When connected with deeper-rooted first-order structures, higher-order faults and shear zones enhance permeability in lo- calized and short-lived domains of lower fluid pressures, both acting as pathways and traps for gold-rich fluids (Gunning and Ambrose 1937; Robert et al. 2005). Studies on orogenic gold provinces have documented recurrent structural controls on min- eralization, including (i) rheological anisotropies (Vearncombe et al. 1989; Kerrich and Wyman 1990; Hodgson 1993); (ii) struc- tural anisotropies (regional faults intersections, early architectural features); (iii) geometrical flexures, jogs, and step-overs of fault zones (Colvine et al. 1984, 1988; Weinberg et al. 2004; Hodkiewiecz et al. 2005; Micklethwaite et al. 2010); (iv) anticli- nal hinges (Etheridge et al. 1983, 1984; Cox et al. 1986; Goldfarb et al. 2005; Kolb 2008; Perrouty et al. 2012); (v) high-angle reverse shear zones (Kerrich and Allison 1978; Robert and Brown 1986; Sibson et al. 1988; Sibson 1990; Robert and Poulsen 2001); (vi) shallow-dipping reverse shear zones (Tunks et al. 2004; Kisters 2005); and to a lesser extent, (vii) normal shear zones (Vearncombe 1992; MacKenzie and Craw 1993; Kwelwa et al. 2018). Such structural geometries resulting from Editorial handling: J. Kolb Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00126-019-00927-y) contains supplementary material, which is available to authorized users. * Nicolas Mériaud meriaud.nicolas@gmail.com 1 Centre for Exploration Targeting, School of Earth Sciences, The University of Western Australia, Crawley, Perth, Western Australia 6009, Australia 2 Perseus Mining Côte d’Ivoire, Cocody 2 Plateaux Vallon, Quartier Lemania 28, BP 571, Abidjan, Côte d’Ivoire Mineralium Deposita https://doi.org/10.1007/s00126-019-00927-y