Since the discovery of mesoscale eddy deposition in the 1970s, the traditional view of ocean currents on the continental shelf and adjacent areas has changed. At water depths over 200 m, it is difficult to observe directly the processes of denudation, transportation, and deposition generated by mesoscale eddies. Till present, the discussions about the mesoscale eddy are only in the domains of oceanphysics and marine biology. It is known that an edgewise structure, characterized by flat-pebble conglomerate exists within limestone beds, which is called edgewise limestone, that are widely exposed in the lower part of the Lower Ordovician Strata in Yanshan region. It is shown that the edgewise limestone beds are characterized by coarsening-upward sequences, deformed bedding, inverted V-shaped cracks, microcrystalline glauconite-rich surfaces of flat-pebbles with suborbicular arrangement along long axes, glauconite-rich cements, folded and flowing structures, and ring-shaped wavemarks. It is suggested that the edgewise limestone sequence is formed by marine mesoscale eddies soon after deep-water carbonate deposition in an area from the outer shelf to the upper slope during early Ordovician. A mesoscale eddy deposition model of edgewise limestone is proposed.