79 percent of the rock in the watershed of south branch newport creek belongs to the llwellyn formation. 7 percent belongs to the pottsville group, 7 percent belongs to the mauch chunk formation, and 7 percent belongs to the pocono formation. 70 percent of the soil in the watershed is of the udorthents-urban land-volusia series. the remaining 30 percent belongs to the lackawanna-arnot-morris series.