Interstate 99 Skytop roadcut, Skytop, State College, Centre Co., Pennsylvania, USA
|Latitude & Longitude (WGS84):||40° 50' North , 77° 58' West|
|Latitude & Longitude (decimal):||40.83333,-77.96667|
|Köppen climate type:||Dfb : Warm-summer humid continental climate|
First road cut along Interstate 99 at Skytop, in sandstone, revealing extensive pyrite vein mineralization with associated Pb-Zn minerals and a wide variety of secondaries. Crushed rocks quickly weathered to secondary sulfates giving the water a very acidic pH. Primary mineralization is pyrite with associated marcasite, sphalerite, and minor galena, chalcopyrite. Other non-metallic minerals are pinkish massive ankerite and baryte. REE phosphates have also been documented, monazite containing the lighter lanthanides as well a some thorium; xenotime-(Y) containing the heavier lanthanides as well as yttrium.
NOTE: Coordinates were generated based on highway, topographic and satellite imagery maps and place the location on center of the roadcut.
Smith (1977), p. 209) noted that A.V. Heyl (personal communication, 1972)reported P. D. Krynine's finding barite and galena in veinlets in the lower Tuscarora quartzite in this area. Smith himself reported major [>10%] amounts of finely crystalline pyrite and drusy quartzite in the Bald Eagle Sandstone. The bitter odor of the mineralization was noticable while driving by prior to the start of construction of I-99.
36 valid minerals.
Rock Types Recorded
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Entries shown in red are rocks recorded for this region.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
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443.8 - 485.4 Ma
Age: Ordovician (443.8 - 485.4 Ma)
Stratigraphic Name: Juniata Formation
Description: Grayish-red, very fine to medium-grained, crossbedded sandstone, and grayish-red siltstone and shale; merges with underlying Bald Eagle Formation to the south; not present east of Susquehanna River, except at Spitzenberg Hill area (Berks County).
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052.