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Browse Table of Contents >> Browsing Northampton County, NC p.440
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| Full Text: | 440 NORTHAMPTON COUNTY Pyrite is common in all the limestones, especially in those high in argillaceous and carbonaceous matter. Usually it is in small cubes along bedding planes, but north of Hellertown the writer has found a spherical concretionary mass of pure pyrite about one and one-quarter inches in diameter in the massive dolomitic limestone. In several of the limonite mines once worked in the county, considerable pyrite was encountered in the lower levels, both in those deposits contained within the Hardyston quartzite and those of the limestones. As suggested in the discussion of the origin of iron ores, this furnishes some evidence for the view that all the iron of the limonite ores was derived from pyrite. Pyrite is fairly common in the Jacksonburg cement rock, particularly associated with the graphite occurring along slickensided surfaces. In the Martinsburg slates one occasionally notes small cubes of pyrite or cavities resulting from their removal. Similar occurrences are common in the talc and serpentine of Chestnut Hill. MARCASITE (FeS,) Occasionally marcasite is found in association with pyrite and not sharply distinguished from it. HA LI I)ES HALITE (NaC1) Halite is not known to occur in Northampton County, but recently the writer has described casts of halite crystals in an Allentown Beekmantown limestone quarry belonging to the Keller Estate in Portland. They occur on the bedding planes at several horizons and range in size from one-eighth to one-quarter inch. The casts show hopper-shaped crystals and occur in a dolomite rock containing some argillaceous matter. FLUORITE (CaF2) Fluorite has been found in several places throughout the limestones of Pennsylvania. Wherever noted by the writer it occurs as purple or occasionally light green particles in calcite or dolomite veins. In Northampton County, it has been observed in thin calcite veins in the Beekmantown limestone outcrops in the southwestern part of the race course of the Nazareth Fair Grounds in the southwestern part of Nazareth. In Lehigh County it has been found in similar thin veins within the Jacksonburg limestone in several cement quarries and probably will eventually be found in some of the cement quarries of Northampton County. It also has been reported from the serpentine quarries of Chestnut Hill. 48 Pa. Acad. Sd. Proc., vol. XI, pp. 55-57, 1937. |
| Collection: | Pennsylvania Geological Survey |
| Series: | Fourth Series, Bulletin C 48 |
| Book: | Northampton County Pennsylvania Geology & Geography |
| Imprint: | Harrisburg, Pa.: Dept. of Internal Affairs, Topographic and Geologic Survey, 1939. |
| Section: | Mineralogy |
| Author: | Benjamin L. Miller |
| Co-Author: | |
| Project Source: | Lehigh University Digital Library Projects |
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