Aurora Mine, Areponapuchic (Areponapuchi; Areponamichic), Bocoyna Municipality, Chihuahua, Mexicoi

Regional Level Types
Aurora Mine	Mine
Areponapuchic (Areponapuchi; Areponamichic)	- not defined -
Bocoyna Municipality	Municipality
Chihuahua	State
Mexico	Country

The La Aurora deposit is about 600 meters below the rim of the Urique canyon and is reached from Areponapuchic by foot in about 4 hours, or by horse over another trail in about 5 hours. It was discovered in the spring of 1944 and operated by Sres. Nesbitt, Silva, and associates until mining ceased on October 27 in the following fall. The vein crops out discontinuously for nearly a kilometer along the wall of a deep canyon tributary to the Urique. It strikes northwest and dips about 75° NE., occuping a fault whose displacement though not determined with accuracy obviously is not. great. Although the vein was prospected at intervals along its length, commercial deposits were found in only two short sections. One section is along a slight bend in the vein, near the top of a steep spur, and the other is on a steep hillside where the vein divides into two parts. The length of the higher section is 130 meters and that of the lower, 25 meters; the vertical range of mining is 20 meters.

Generally both the footwall and the hanging wall are well defined. The zone between them averages a meter in width in the higher section and has a maximum width of about 5 meters in the lower one. The material between the walls consists of breccia and calcite in different proportions. Above, where most of the usable calcite was found, breccia is nearly absent and the zone is occupied by a calcite vein with debris-filled central cavities. Most of the usable crystals were found firmly embedded in this debris. Below, cavities occur also but are not filled with debris, and usable crystals are recovered by breaking them from the walls. The common habit of the crystals is a simple scalenohedron. Some small twin crystals were found in the lower section. The twins are of the same type as those at Areponapuchic, but they are shaped like a flat shaft with a barb on the end rather than like an arrowhead.

Despite the fact that the La Aurora deposit was mined by a few men for a few months only, its yield was much better than average. It produced 26K pounds of high-grade optical calcite and about 450 pounds of suboptical calcite. Work had been halted in the lower adits some time before all mining ceased, as it did not pay, but the yield from the upper section was at its maximum when work had to be stopped. If mining should be resumed, adit k should be extended beneath adit c. If the yield is satisfactory there, another adit might be driven 10 meters below adit k. It is doubtful whether further mining in the lower adits would pay, although more might be done if work above were profitable. A closer inspection of the outcrops should be made.