Digital Geodata Series
DGS04-3 Magnetic Anomalies of New Jersey
Magnetic 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 magnetic contours
as polygons, at 100 gamma intervals. The contours are based on magnetic data
in New Jersey and vicinity. The New Jersey contours were clipped at the state
outline.The magnetic 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 it ranges from 55,000 - 56,000 gammas.
The shape, database and Arcview legend files are combined with FGDC compliant
metadata files in a compressed 'zip' file,
dgs04-3.zip, for delivery over the Internet.
This Sample Image is for illustration purposes only.