THE DILLSBURG, YORK COUNTY, PENNSYLVANIA MAGNETITE DEPOSIT

The most prosperous iron deposits along the East Coast were that of the Cornwall-type iron deposit, so named for the wealthiest iron mine located in Lebanon County, Pennsylvania. One of theses such deposits was located about 1.25 miles east of Dillsburg, York County, Pennsylvania. Using about 30 open pits and underground mines, approximately 1.5 million tons of magnetite was removed between 1828 and 1888. 10 different mines can be identified in this 0.75 square mile area. The most productive operation was the Underwood mine where approximately 25,000 tons of ore averaging 40% iron was removed. The thickest vein of magnetite, measuring 18 feet thick was found at this mine. Other mines in this district were the McCormick, Logan-Longnecker, Smyser, Altland, Bell Jauss, King, Price and Grove. Unlike many iron deposits during the 19^thcentury, Dillsburg never had a furnace in the immediate area for which the ore was being used. All of the ore mined was purchased by contract in use of other furnaces throughout central Pennsylvania.

As a result of the finding of the rich magnetite ore on the Mumper property in 1847, landowners and investors discovered magnetite on neighboring properties and suddenly the area grew in prosperity and appeared as a small mining town. Other than a closing of most of the mines late in 1873 (known as the panic of 1873), the mines worked continuously until about 1888. The Jauss Mine was the last operation working which closed in 1908, but not before attempting to convince famous inventor Thomas Elva Edison and his son to invest interests. They never invested in the Jauss property.

In 1944, the U.S. Bureau of Mines conducted a magnetic survey of the Dillsburg magnetite fields. This was followed by an intensive diamond-drill program to investigate future iron deposits. It was verified with these studies that the magnetite deposits lies between two diabase bodies where the Triassic-aged limestone conglomerate and sandstone were metamorphosed to form the deposit.