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Geology-Mineral District

yet known, unproductive. They are followed when they are found to yield three inches of galena, that being the least vein it is thought worth while to pursue through rock, and it is very rare indeed that a continuous vein is found [extending] exceeding one foor in thickness. The horizontal direction of the fissure is more uniform; those producing the most ore are almost universally running nearly east and west. Near Mineral Point some fissures running north and south produce good ore, but they are for the most part horizontal beds (of limited width) between the strata, and out of these directions it is [difficult] rare to find a productive fissure. The smelters think they can distinguish the ores that are found in different fissures- that form and east and west fissure being perfectly crystalized, of a smooth surface, striae indistinct; that from a north and south fissure of chrystaline structure with two sets of striae very distinct, crossing each other at right angles; and the ore from a quartering fissure crystaline with many sets of striae crossing each other obliquely; and to some extent I had opportunity of proving their observations correct. The fissures appear to be limited in length

69

120

Geology-Mineral District

yet known, unproductive. They are followed when they are found to yield three inches of galena, that being the least vein it is thought worth while to pursue through rock, and it is very rare indeed that a continuous vein is found [extending] exceeding one foor in thickness. The horizontal direction of the fissure is more uniform; those producing the most ore are almost universally running nearly east and west. Near Mineral Point some fissures running north and south produce good ore, but they are for the most part horizontal beds (of limited width) between the strata, and out of these directions it is [difficult] rare to find a productive fissure. The smelters think they can distinguish the ores that are found in different fissures- that form and east and west fissure being perfectly crystalized, of a smooth surface, striae indistinct; that from a north and south fissure of chrystaline structure with two sets of striae very distinct, crossing each other at right angles; and the ore from a quartering fissure crystaline with many sets of striae crossing each other obliquely; and to some extent I had opportunity of proving their observations correct. The fissures appear to be limited in length

69