New Jersey Department of Environmental Protection, New Jersey Geological SurveySoil pH is the measure of the pH of soil water, which depends on the hydrogen ion (H+) activity in solution. Soils become naturally acidic for three major reasons: rainfall and leaching, acidic parent material, and decay of organic matter which produces hydrogen ions. Sulfide-bearing (pyritic) Cretaceous and Cenozoic marine and estuarine sediments, depicted on this map, are potential acid-soil producers. The development of acid-sulfate soils occurs when sulfide minerals, such as pyrite and/or elemental sulfur, in reduced sulfidic sediments, oxidize upon air exposure through drainage or earth-moving operations. The overall acid-sulfate soil-forming process involves a complex chain of reactions that connect the oxidation of iron sulfides to the release of iron oxyhydrates (+ hydronium jarosite, H3OFe3+3(SO4)2(OH)6) and sulfuric acids. For pyrite and marcasite, the overall reaction is: FeS2 + 3.75O2 + 3.5 H2O -> Fe(OH)3 + 2H2SO4 (pyrite/marcasite) (iron oxyhydrate) (sulfuric acid) Acid-sulfate soil formation occurs if the reduced sulfur components exceed the acid-neutralizing capacity of adsorbed bases and easily weatherable silicate and carbonate minerals. Natural Resource Conservation Service reports (see for example Soil Survey of Monmouth County) demonstrate that soils developed on these sulfidic, non-calcareous, marine sediments are strongly (pH < 5.5) to extremely acid (pH < 4.5). Depicted on the geologic map are the sedimentary units with the potential to produce acid (sulfate) soils: Kirkwood, Shark River, Manasquan, Hornerstown, Tinton, Sandy Hook Member of the Red Bank, Navesink, Wenonah, Marshalltown, Englishtown, Woodbury, Merchantville, Cheesequake, Magothy, and Raritan Formations.ArcGIS DynamicMapLayerhttps://hub.arcgis.com/datasets/de0d7fe5d3fd4ce8b459431554d0f817_27engNew Jersey Department of Environmental Protection's (NJDEP) Bureau of GISPublicPotential Acid Producing Soils in New Jersey [New Jersey]Web servicesNew JerseyLast Modified: 2023-12-27