General Geology:

There have been several prolific producing wells in and around the area over the years, typically confined to the Ordovician Trenton (Sunny Brook) formation and the underlying Stones River formation. These wells typically penetrate the Devonian Chattanooga Shale formation in regional lows. These lows are the subject of much debate but in general are thought to be caused by the collapse of paleo-karst features (caves) in the Sunny Brook during or very soon after deposition of the Chattanooga Shale. The collapse of these features is thought to be a reaction to the overburden and movement along faults and joints that are coincident with the emplacement of the carbonates of the middle and upper Ordovician rocks. The features themselves are thought to be caused by hydrothermal waters migrating through the rock via fractures, faults and fissures. The migration of these waters is thought to cause the limestone to change to dolomite thus causing re-crystallization and shrinkage. If enough native rock is dissolved small holes and pathways can develop. These are typical of current day Karst environments (sink holes). The difference is that these sink holes represent enhanced porosity zones within the massive carbonate sediments and a perfect accumulation point for migrating hydrocarbons.