New Jersey Department of Environmental Protection, New Jersey Geological SurveyMagnetic anomalies are produced by variations in the distribution of iron minerals, usually magnetite, in the rocks of the Earth's crust. Igneous and metamorphic rocks can be very magnetic. By comparison, sedimentary rocks are usually nonmagnetic. Magnetic anomalies therefore provide a way of mapping exposed and buried crystalline rocks. Magnetic Anomalies of New Jersey contains a GIS shapefile of aeromagnetic contours as polygons, at 100 gamma intervals. The contours are based on aeromagnetic data in New Jersey and vicinity. The New Jersey contours were clipped at the state outline.The aeromagnetic anomalies at 100-gamma intervals have lows ranging from -200 to -300 gammas and highs ranging from +1200 to +1300 gammas. A regional gradient was removed by using a corrected geomagnetic reference field. For New Jersey the field is 55,000 gammas.ArcGIS DynamicMapLayerhttps://hub.arcgis.com/datasets/4a4a81cf1f7f4529aab426747c29d79b_17engNew Jersey Department of Environmental Protection's (NJDEP) Bureau of GISPublicMagnetic Anomalies (gammas) in New Jersey [New Jersey]Web servicesNew JerseyLast Modified: 2021-11-08