Abstract Since the early 1800’s mining has been an important industry in New York. In 1989 the value of nonfuel mineral production reached $745.2 million (Harrison and Kelly, 1989). Nationally the State ranked 14th in the value of nonfuel minerals produced. New York was the only State in the Nation that produced wollastonite and one of two States that mined garnet The State ranked third in output of salt and zinc, and fourth in crude talc production. Of the minerals processed in the State, New York ranked second in synthetic graphite and fifth in primary aluminum output. Iron was first discovered in 1812 near Antwerp and mined until 1910 when competition from the Lake Superior ores rendered the Antwerp ores uneconomic (Brown, 1983). During the 1830’s galena was discovered in calcite veins 2 km south of Rossie and mined mainly between 1836 and 1852. Marble for dimension stone was mined in the Gouverneur area from 1878 to 1941. Talc mining began in Fowler and Talcville in the 1870’s and continues nearby today. In 1915 zinc mining began in the Balmat-Edwards district, one of the great zinc producing districts in North America. To date over 37 million tons of ore with a grade of 9.4% Zn and 0.5% Pb have been produced. Wollastonite has been produced since 1979 from the contact metasomatic Valentine deposit near Harrisville. In the Adirondack Highlands the commodities of economic significance are iron, titanium, garnet and wollastonite. The latter two continue to be major resources whereas iron and titanium are no longer produced The important iron deposits are located at Port Henry, Lyon Mountain and Star Lake, and the only titanium (ilmenite) district is located at Sanford Lake. In the early 1950’s the Cabot Corporation began mining wollastonite at Willsboro for use as a filler and ceramic base. The abrasive quality of Gore Mountain Gamet was appreciated as early as 1846 but 32 years elapsed before commercial mining of garnet was undertaken. Various modes of origin have been proposed for the deposits we will visit on this field trip. A high-grade regional metamorphism m~ks primary features and has challenged generations of geologists in their quest to understand the interplay among the sedimentary, igneous, metamorphic and hydrothermal processes that led to economic mineralization in the Adirondack Mountains. Important question regarding the genesis of the deposits remain as is evident from the papers that follow and the observations you

Abstract The presence of wollastonite near Willsboro in the northeastern Adirondacks has been known since the early nineteenth century (Buddington, 1977). Without an- obvious use, the occurrence was of little interest except as a mineralogical curiosity until the early 1950’s when the Cabot Corporation began mining it for use as a filler and ceramic base. Product development resulted in such uses as a tempering agent in ceramics, flux in welding rods, an alloying agent, an extender in plastics and, recently, as a substitute for short fiber asbestos. With the opening of the large open pit mine in Lewis, ten miles SW of Willsboro, in 1980, the original Willsboro mine was closed. Both properties are now owned by NYCO Minerals, Inc. The Willsboro mine is located in the Willsboro 15 quadrangle and the Lewis mine is in the Au Sable Forks 15’ quadrangle. Location of these quadrangles is shown in Figure 1.