The accompanying report was undertaken at the request of the State geologist of New Jersey, with the aim of presenting in a single publication the major facts known concerning the distribution and manner of occurrence of iron ores of the State. Many items of interest with reference to the iron mines have been published in the various reports of the New Jersey Geological Survey, and much information relating to the history of the different mines has been given in them. This material, however, is scattered through forty volumes of the Annual Reports of the Survey, and, since many of these are out of print, is inaccessible to those to whom it might be of service. Moreover, many of the mines that were formerly worked have been lost sight of, an...