=6–5= Correcting Errors in Patented Mineral Surveys: As a general rule, the record of a patented mineral survey should not be changed or amended. When such errors are discovered, a pencil notation on the index card and/or on the field notes may be appropriate. Reported errors generally stand on their own merit and are contained in the field notes of the reporting survey. [Illustration: FIG. 8 ] GLOSSARY OF MINING TERMS ADIT: a horizontal entry into a mine with one opening to the surface, commonly and erroneously called a tunnel. (A tunnel is open at both ends.) ALLUVIUM: unconsolidated sedimentary deposit, e.g. stream bed of sand and gravel. ANTICLINE: a convex fold in sedimentary beds of rock (opposite: syncline). APEX: top of a vein or lode. ASSAY: a test to determine the quantity of mineral in a given sample. May be by a miniature smelting process in the laboratory, called a fire assay; or by use of chemicals, called a chemical or wet assay. BACK: the roof of a horizontal opening such as an adit, drift or crosscut. BONANZA: a rich body of ore. BEDROCK: uppermost layer or segment (portion) of rock in place. BREAST: the end, heading or working face of an adit, drift or crosscut. CHIMNEY: a vertical ore body, tubelike in shape. CHUTE: (ore) chute for transferring broken rock in a mine; usually from a stope to a haulage passage. COBBING: hand sorting of ore. COLLAR: top of a shaft or winze; the timbers or concrete at the upper end. COLOR: a particle of free gold. CONCENTRATOR: a device for separating and concentrating mineral from rock by mechanical means. CONTACT: the meeting of two geologic formations. CONTACT VEIN: a vein along the contact. COUNTRY ROCK: rock surrounding a vein or lode, extending throughout the area. CRIBBING: a wall of light timbering between heavy supports at either vertical or horizontal mine working. CROSSCUT: a horizontal opening such as an adit driven across the vein or ore body. CUT: an open working driven into a hillside to expose underlying rock. DIKE: a vertical or near vertical fissure filled with volcanic rock. DIP: the vertical angle a vein or sedimentary bed makes with a horizontal plane. DRIFT: a horizontal opening (such as an adit) driven along the vein. FACE: the last working end of an adit, drift, crosscut or cut (same as breast). FAULT: A dislocation along a crack in the earth’s surface (may be horizontal, vertical or a combination of both); a failure along a line of stress; usually associated with earthquakes, but movement may be slow. FISSURE: a crack in the earth’s surface; if filled with vein material becomes a fissure vein. FLOAT: a piece of ore detached from a vein or lode, lying loose, not in place. FLOOR: the lower surface of a mine working, i.e. the floor of a drift.