Gold Occurrences in Pennsylvania

Pennsylvania has a long and rich tradition of mining especially for anthracite and bituminous coal as well as iron. What is not generally known however is the state is also produced a considerable amount of gold. It has a well-trained workforce of miners many of whom have a tendency to be prospectors. Because of this some iron miners down around Cornwall have actually produced more than 61,000 ounces of gold while they were mining the magnetite iron ore. Aside from the mine at Cornwall another mine that reportedly produced gold from magnetite was the Grace mine in Morgantown.

There were a series of three openings to the iron deposit in Cornwall located at Big Hill, Middle Hill and Grassy Hill that were originally owned by the Cornwall Ore Banks Co., but were eventually owned by Bethlehem Steel who eventually closed the mines in 1979.  This deposit of magnetite was produced by the replacement of limestone by hydrothermal activity during the Jurassic from a diabase intrusive, so in effect the deposit is a skarn.

The eastern part of the state is covered with crystalline rocks producing potential gold lodes as well as placer gold. This gold weathers out of the crystalline rocks and is collected in the rivers and streams of eastern Pennsylvania. This is not the only source of gold however, in the northern part of the state the last glacier left placer gold in the terminal moraines found in Pennsylvania.

There are several streams producing placer gold that came in Lancaster and York Counties in glaciers that have advanced into the state during the past million years. Any of these glaciers were capable of bringing gold down from Canada where one of the richest gold belts the world the Abitibi is found in Qu├ębec and Ontario. According to some geologists there have been as many as 24 episodes of glaciation that have affected the northern part of the United States in the past 2.5 million years.
Although the eastern part of the state is mostly covered with crystalline rocks that produce gold as lode gold that weathers out so it becomes placer gold that collects in the rivers and streams found in eastern Pennsylvania.
One of the places where gold has been found is along the Susquehanna River where it has been found as both nuggets and flakes of gold. Generally Wyoming County has been a good place to look for gold as well as in the surrounding counties.  In York County  placer gold is associated with the deposits of diabase that make up the tops of many ridges. The action of weathering releases the gold from bedrock allowing it to migrate downhill into the streams and rivers in the area.
During the Civil War the great battle at Gettysburg was fought on some of these diabase ridges with names like Little Round Top or Cemetery Ridge. There is no doubt that the rivers and streams around the Gettysburg Battle Site undoubtedly contain gold. 
The best way to find out where the gold is in Pennsylvania is to research old newspapers and town histories.  The state only keeps track of commercial mining operations and not that of individual prospectors. Old newspapers are often the source of stories about where one of the local citizens has found gold in their town.
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There are several gold prospecting clubs that are active in Pennsylvania that can supply more information about Pennsylvania gold.

Our thanks to Stephen Shanks of the Pennsylvania Geological Survey for additional information.