POROSITY OF THE EOCENE CASTLE HAYNE LIMESTONE, CENTRAL COASTAL PLAIN, NC

Porosity of the Eocene Castle Hayne Limestone was determined based on petrographic analysis of samples from two quarries in the central coastal plain of eastern North Carolina. The quarry near Richlands, NC, is developed in the Comfort Member of the Castle Hayne Limestone. Here the porosity averages 15% and ranges up to 35%. Pores are small and range up to 5mm in the long axis. Porosity types are primarily molds of dissolved bivalves and other bioclasts. There is slight porosity reduction by pore lining dogtooth and microcrystalline spar. The quarry near New Bern, NC, is developed in the Spring Garden Member of the Castle Hayne Limestone. The porosity averages 21% and ranges up to 37%. Porosity types include molds of dissolved bivalves and other bioclasts, enhanced molds and vugs. Porosity reduction ranges from thin pore-lining cements to occlusion. The primary control on the development of Castle Hayne porosity is the distribution of bioclasts/facies.