IRON OXIDE STAINING IN THE TUSCARORA SANDSTONE

Iron oxides were analyzed from the Tuscarora sandstone using X-ray diffraction and SEM methods. A series of twenty samples were collected from the Tuscarora formation located on Jack’s Mountain that showed iron-oxide staining. The surface of the usually white quartz arenite exhibited varying hues of red, yellow, blue, and green. The iron oxide present in the rock is either residual from the weathering of sulfides, or it was transported into the rock from an iron-bearing fluid. Chemical analysis with the SEM revealed that the rock contained no residual sulfide but, an abundance of in-situ Iron oxide. Along with the in-situ iron, elements associated with alkali and plagioclase feldspars were found. The abundance of calcium, sodium, and potassium found in the samples suggest that a calcium rich brine flowed through fissures in the rock during deformation producing altered silicates. The salts, iron oxides, and silicates were more than likely associated with a fluid that was transported through the rock, not with the weathering of the sulfide out of the rock.