Hillside Mine (Happy Jack MS 920 claim; Camp MS 919 claim; Seven Stars MS 916 claim), Bozarth Mesa, Bagdad, Eureka District, Yavapai Co., Arizona, USA
|Latitude & Longitude (WGS84):||34° 37' 58'' North , 113° 12' 35'' West|
|Latitude & Longitude (decimal):||34.63278,-113.20972|
A former underground Au-Ag-Zn-Pb-Cu-U-V mine located on 6 patented claims in sec. 16 & 21, T.15N., R.9W., Boulder Creek vicinity, a little more than 3 miles north of Bagdad and east of Bozarth Mesa. located March 11, 1887 by John Lawler and B.T. Riggs. Discovered on March 11, 1887 and owned by John Lawler & B.T. Riggs, then sold to H.H. Warner (June, 1890-1904)(Seven Stars Mining Co.); John Lawler (1904- ); Hillside Mines, Inc. (1934-1940); Boulder Mining Co. (1940-1942); State of Arizona (1942-1944); East Vulture Mining Co. (1944-1951).
The deposit is a typical fissure vein in muscovite schist, an important member of the Yavapai schist. The vein has a N.10ºW. strike at the south end and changes to a N.25ºE. strike at the north end. The dip is not uniform but averages between 75º to 80º in a westerly direction. Faulting before and after mineralization has been important. The main vein and several branches occupy a zone of faults antedating the veins, and sufficient movement along the faults occurred after mineralization to form a 3 foot zone of gouge and fault breccia in which unbrecciated vein material is found as irregular veinlets. Branching veins appear on both sides of the main vein and those to the east in general dip west less steeply than the main vein, whereas those on the west side of the main vein are nearly vertical. Small veinlets of sulfide, with or without quartz, fill minor fractures in the Hillside Mica Schist. The main vein averages 2½ feet (75 cm) in width on the upper levels and 4 feet on the 800 & 900 levels.
Four periods of quartz-sulphide deposition have been recognized from the banding and local comb structure. Some intramineralization faulting is indicated by microbrecciation of the sulphides and cementation by later quartz. The common sulphide minerals occur usually in blebs or bunches in quartz.
Strike faults locally cut out the vein and elsewhere repeat it. In other places the vein has been broken so completely as to form only an unrecognizable part of the gouge. After the strike faulting that followed mineralization there were offsets along north-dipping (25º-45º) cross faults. In general these late cross faults have formed clean-cut breaks, and the vein on the hanging wall side of the cross faults has been displaced 1 to 25 feet eastward.
Workings include 7,000 of development work by Lawler (1887-1892), by 1914 there were some 11,000 feet of workings, ultimately over 16,000 feet of workings. The shaft is 765 feet deep to the 1000 level. The vein was worked for 2,400 feet along the strike and stoped almost completely above the 700 level for an average length of 2,000 feet. Production included 58,748 oz. Au, 1,315,264 oz. Ag, 6,503,028 pounds Pb, 3,300,524 pounds Zn and 398,813 pounds of Cu. (to 1951).
35 valid minerals. 4 (TL) - type locality of valid minerals.
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.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
1400 - 1600 Ma
|Middle Proterozoic granitic rocks|
Age: Calymmian (1400 - 1600 Ma)
Description: Mostly porphyritic biotite granite with large microcline phenocrysts, with local fine-grained border phases and aplite. Associated pegmatite and quartz veins are rare. This unit forms large plutons, including the Oracle Granite, Ruin Granite, granite in the Pinnacle Peak - Carefree area northeast of Phoenix, and several bodies west of Prescott. (1400-1450 Ma)
Comments: ~ 1.4 Ga
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. 
Wilson, E.D., Cunningham, J.B., and Butler, G.M. (1934), Arizona lode gold mines and gold mining, Arizona Bureau of Mines Bull. 137: 24-25.
Metzger, O.H. (1938), Gold Mining and Milling in the Wickenburg Area, Maricopa and Yavapai Counties, Arizona: US Bureau of Mines Information Circular 6991: 66.
U.S. Atomic Energy Commission RMO-679 (1950).
Wilson, E.D., et al (1950), Arizona zinc and lead deposits, part I, Arizona Bureau of Mines Bull. 156: 125-128.
Axelrod, J.M., et al (1951), The uranium minerals from the Hillside mine, Yavapai County, Arizona, American Mineralogist: 36: 1-22.
Anderson, C.A., et al (1955), Geology and ore deposits of the Bagdad area, Yavapai County, Arizona, USGS PP 278: 43, 47, 48-49, 83.
McKelvey, V. (1955), Search for uranium in the United States, USGS Bull. 1030-A: 26-27.
Frondel, C.C. (1958), Systematic mineralogy of uranium and thorium, USGS Bull. 1064: 119, 125.
Galbraith, F.W. & D.J. Brennan (1959), Minerals of Arizona: 35, 51, 52, 66.
Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II. John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged, 1124 pp.: 236, 238.
Granger, H.C. & R.B. Raup (1962), A reconnaissance study of uranium deposits in Arizona, USGS Bull. 1147-A: 1-54.
Meeves, H.C. (1966), Nonpegmatite beryllium occurrences in Arizona, Colorado, New Mexico, Utah and four adjacent states, US Bureau of Mines Report of Investigation 6828: 59.
Frondel, C., et al (1976), Mineralogy of the zippeite group, Canadian Mineralogist: 14: 429-436.
Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 111, 112, 130, 155, 159, 170, 229, 242, 248, 263, 313, 365, 375, 387, 407, 430.
US Atomic Energy Commission Preliminary Reconnaissance Report Yavapai County: 1.
USGS Bagdad Quadrangle map.
U.S. Bureau of Land Management Mining District maps.
MRDS database Dep. ID #10027619, MRDS ID #M003538; and, Dep. ID #10210277, MAS ID #0040251134.