Vein features in the Ouachita mineral province, Arkansas

Within the widespread vein system of the Ouachita Mountains, Ark., many veins exhibit features attributable to (1) deformation preceding and accompanying vein formation, (2) influences of diverse wall rocks, and (3) movements of vein-forming solutions. Most veins follow incipient or well-defined longitudinal fractures closely related to fold systems in quartzites, slates, and thin limestones of the Ouachita anticlinorium. Many veins are fissure fillings. Locally, displacements of opposite walls of veins during mineralization have produced lineated and reticulated mats of quartz crystals which indicate relative directions of movement.