Photomicrographs of barite cements. (A) SEM-BSE imaging of barite cement location in fracture, posterior to matrix pervasive siderite (Sd2) precipitation. Some pores are clogged by authigenic illite (Ilt) (yellow arrow). In black, the porosity (Sample C-2352, Roemerberg). (B) SEM BSE imaging of barite (Brt) filled fracture, and anterior siderite matrix pervasive cement (Sd2). Quartz detrital grains on the fracture borders show well authigenic quartz overgrowths (black arrows) In black, the porosity (Sample D-2540, Roemerberg). (C) SEM-BSE image of barite cemented fracture (orange arrow). The upper fracture border presents a cataclastic deformation of grains in black, the porosity (Sample B-2375, Roermerberg). (D) SEM-BSE image of barite cross spanning partially cemented fracture. The fracture is entirely cemented by siderite cement (Sd3) In black, the porosity (Sample B-2686, Roemerberg). (E) Polarised transmitted light image of barite needle-shaped fracture cements (Sample C-2537, Roemerberg). (F) Transmitted light image of platy and needle-shaped barite cement. A posterior phase of siderite (Sd3) is present. The fracture remains partially open (sample D-2547, Roemerberg).