Research Review : Areal Extent , Hydrogeologic Characteristics , and Possible Origins of the Carbonate Rock Newburg Zone ( Middle - Upper Silurian ) in Ohio

The name Newburg has been applied to a highly permeable zone, 0.3 to 9 m thick, occurring in a granular or vuggy dolomite. The zone occurs in carbonate rocks of Middle to Late Silurian age across much of Ohio. Known also to well drillers as the "Second Water" in the "Big Lime" carbonate sequence, the Newburg zone is a source of hydrocarbons in northeast Ohio, brines in southeast Ohio, and a widespread source of water over much of west-central Ohio. Close to recharge areas, the quality of the water is comparable to that of the overlying carbonate rocks; thus, the Newburg zone warrants further investigation as a source of water for domestic use. Theories for the porosity and permeability of the Newburg zone include: 1) deposition of carbonate or quartz sand along an erosional surface and later lithified to porous and permeable sandstone; 2) dissolution of fossils within Silurian reef complexes; 3) fracture-induced porosity along thrust faults developed during the Alleghenian orogeny; and 4) a combination of these processes. Differences of the characteristics of the Newburg zone and interpretation of these characteristics at different localities indicate that the multiple-process theory is valid and that the Newburg zone is not a single, continuous stratigraphic feature. OHIO J. SCI. 91 (5): 209-215, 199