n. Rock consisting wholly or in large part of calcareous material or carbonate of lime.n. A limestone in the New York series of formations, originally called the Scutella and Upper Pentamerus limestones of the Lower Helderberg group of strata. It belongs to the lowest or Helderbergian division of the Lower Devonian, lying near the top, beneath the Port Ewen beds and above the New Scotland limestone. It abounds in fossil remains, and from its purity is highly esteemed both as a construction stone and as a flux in smelting.n. A division of the Lower Silurian of New York State and the adjoining regions, originally termed by Eaton the “Calciferous sandrock.” It is regarded as the lowest member of the Lower Silurian, resting on and graduating by easy changes from the Potsdam sandstone beneath. The rock in northern New York and the Lake Champlain basin is largely a limestone, at times magnesian, and carries a profuse and highly interesting marine fauna. In the Mohawk valley the beds are almost devoid of organic remains, are highly dolomitic, and have been locally designated as the Little Falls dolomite.