![]() |
||||||||||
19. The Franklin and Ogdensburg Mineral Resource Area The region around Franklin and Ogdensburg in Sussex County is one of
the most famous mineral and mining districts in North America. The bedrock
has yielded more than 330 different mineral species, more than any other
mineral locality on Earth! Many minerals are known only from this area.
Its wealth of zinc ore is responsible for the nickname "The Fluorescent
Mineral Capitol of the World." The two destinations for day trips
are the Franklin Mineral Museum and the Sterling Zinc Mine. Both sites
include museums with displays of fluorescent minerals and mining equipment,
including displays documenting the history of mining development of the
area. The Franklin Mineral Museum (Figure 43) provides access for rock
collecting in the Buckwheat dump, a great pile of rock tailings from the
abandoned open pit and underground mines in the vicinity. The Sterling
Mine offers underground mine tours which examine the methods used and
the history of the mine. It also includes a look at the "Rainbow
Room," a mine passage which intersects a vein of unmined zinc minerals
that are illuminated briefly with ultraviolet light on every tour. Both
sites are open to the public from late spring until early fall. Both also
charge a moderate admission fee. Figure 44 is a map showing the location
of mines in relation to the bedrock geology of the mining district.
The zinc and iron deposits occur as mineralized zones within the Proterozoic
age Franklin Marble. The marble crops out in a long, narrow belt (about
5 miles long and a half mile wide). The marble belt is complexly folded.
The major ore veins occur on both sides of plunging synclines within the
marble. The marble belt is bounded on the north by granitic gneiss of
Proterozoic age that crops out throughout a band of hills along the western
border of the highlands. In this region the hills are called Hamburg Mountains
on the northern side of the Reading Prong extending from around Sparta,
New Jersey northward into New York. The south side of the Franklin Marble
belt is a northeast trending graben of Cambrian age Hardyston Quartzite
overlain by limestones of the Ordovician Kittatiny Group. The primary zinc minerals in the area are willemite, franklinite, and
zincite. Willemite, a zinc silicate and a primary ore mineral in Franklin
area mines, fluoresces an intense bright green under ultraviolet light
(see Figure 45). The host rock for the ore bodies is typically a fluorescent
variety of calcite that fluoresces bright orange-red under ultraviolet
light. Samples of these minerals are the showcase pieces in fluorescent
mineral displays in museums around the world.
The mining district has a long and rich history; highlights are as follows.
The earliest reports of this area suggest that ores of iron and zinc were
being mined before 1750. The early Dutch miners thought the reddish-brown
ore was a form of copper. The first large operation was the Ogden Mine
which opened in 1772 and supplied a charcoal furnace in Sparta. The "Lord
Stirling Pits" also opened in 1772, and was named by the developer,
Lord Stirling (William Alexander, a Major General in Washington's Continental
Army). Lord Stirling's mining ventures failed because, like the Dutch
miners, he attempted to extract copper and iron from the zinc ores. Ogdensburg owes its name to the town Patriarch, William Ogden, who settled
the valley; he and his wife had 22 children in the process. One of his
daughters married Dr. Samuel Fowler, the owner of Mine Hill which includes
the Franklin orebody, and eventually, the Sterling Hill Mine. Fowler was
also unsuccessful in capitalizing on his mining investments because he
was unable to adequately separate the different metals within the ore.
His one success was to develop a zinc oxide-based paint to substitute
for lead-based paint. This was the first practical use of the zinc products,
and in retrospect probably saved the health of thousands, if not many
millions of people! From the early 1800s through the Civil War the most important product
of the mines was iron (magnetite ore). Just before the Civil War practical
uses for alloys of zinc were discovered, and the zinc industry began to
prosper. After a series of legal battles, the mining district was united
under the New Jersey Zinc Company. Full development of large capacity
mining operations of the Sterling Mine and Mine Hill began in 1897. Thomas
Edison invested $3.5 million in an iron mining and milling project, but
his efforts were largely unsuccessful due to competition with the development
of large iron deposits in Minnesota. A mill began operation in 1900 capable
of processing 1500 tons of ore daily. Production rates from all area mines
were fairly steady until mining ceased in the 1980s. The Franklin area
mines remained in the top ten producing zinc districts through most of
the twentieth century. The high maintenance costs, the exhaustion of the
large ore veins, plus the dramatic drop in the price of zinc resulted
in the end of mining operations in 1986. The ore deposits at Sterling Hill were mined to a depth over 2,700 feet
(well below sea level). During the history of mining many fissures were
encountered causing serious flooding problems. Pumping the groundwater
out was a constant expense of operating the mines. Once the pumps were
shut off water eventually filled the underground mines to near surface
level.
|
||||||||||
U.S. Department of the Interior,
U.S. Geological Survey Maintainer: WESP team webmaster contact FOIA || Privacy Statement || Disclaimer || Accessibility URL: http://3dparks.wr.usgs.gov/nyc/parks/loc19.htm This site last updated July 22, 2003 (ps) |
![]() |