Abstracts NEVADA 80 Laramie Cheyenne WYOMING Wendover 76 New Mexico Mineral Symposium Salt Lake City UTAH COLORADO 25 The Twenty-Third Annual New Mexico Min- eral Symposium was held November 9 and 10, 6 Denver 2002, at New Mexico Institute of Mining and 6 Ely 70 Technology, Socorro. Following are abstracts 50 from all talks given at the symposium. 6 Grand Junction 70 4 550 Colorado Springs 24 Pueblo 191 RECOVERY OF THE 17 TON COPPER BOUL- 15 93 DER FROM LAKE SUPERIOR, by Bob Bar- 666 ron, Department of Geological and Mining 5 160 Alamosa Engineering and Sciences, Michigan Tech Uni- Durango 285 versity, 1400 Townsend Dr., Houghton, MI 64 OK 49931, [email protected] ARIZONA NEW MEXICO 87 666 84 Springer For well over a century, the Keweenaw Peninsu- 54 la has served as a home to a multi-billion-dollar 191 copper industry. The roots of mining go back Santa Fe Gallup several thousand years when Native Americans TEXAS 40 Flagstaff 40 first discovered the nearly pure copper and sil- Kingman ver deposited in fissure veins cutting across the 666 Albuquerque Keweenaw Peninsula. Along the sparsely vege- 180 Clovis CA 60 tated shores of Lake Superior and inland lakes 17 54 of the post-glacial period, the Native Americans 60 6 Socorro mined the red metal for possibly 10,000 yrs. The Phoenix 1 380 malleable copper was easily shaped into tools 10 Globe 666 Roswell 180 70 and other valued implements and was traded 25 Silver across North America and perhaps beyond. 70 Alamogordo City As an avid scuba diver and mineral collector 8 Hobbs 3 7 for over 25 yrs, I was drawn to Lake Superior Las Cruces Carlsbad because mineral collecting for fine specimens on Tucson 10 2 the Keweenaw was becoming an activity of the Deming 19 180 20 past. With the closing of many old mines and El Paso the crushing of rock piles, it was becoming TEXAS 285 exceedingly difficult to obtain high-quality Gulf SONORA CHIHUAHUA 10 of 10 specimens. I was spending countless hours sift- California Van Horn ing through old geology maps of the Keweenaw and studying the copper-bearing series along its length when one day it struck me—why not fol- Index map showing the locations referred to in the abstracts. low the fissure veins into Lake Superior and see Geographic Index Map where they cross the offshore shallow reefs? So 23rd New Mexico Mineral Symposium in the summer of 1991, I concentrated my efforts located in the blacksmith and machine shops of road. A hike over relatively flat ground with on a large reef between the old seaports of Eagle the Quincy mine complex, which is slated to arroyos is required to get to the mines. River and Eagle Harbor and realized within a break ground in 2005. The geology of the district was summarized short period of time it was well worth the effort. by Dunham (1935). Hematite is present in dark- During July of 1991, I discovered the largest red botryoidal masses with radiating fibers and piece of fissure vein copper, 30 ft offshore of minor quartz and gypsum. Many of the botry- Great Sand Bay just northeast of Eagle River, HEMATITE COLLECTING IN THE IRON oidal masses are aggregates of rough spheres of Michigan. It measures 19 ft long, 8 ft wide, and HILL DISTRICT, SOUTHWESTERN ROB- hematite that have grown together and often weighs approximately 17 tons. Salvage permits LEDO MOUNTAINS, DOÑA ANA COUN- resemble bunches of small grapes. The rough had to be obtained from the Michigan Depart- TY, NEW MEXICO, by Robert D. Beard, 6259 spheres range in size from less than a millimeter ment of Natural Resources and the U.S. Army to a few centimeters. The botryoidal character is Corps of Engineers before the recovery project South Highlands Circle, Harrisburg, PA 17111 (717) 657-3283 similar to that of manganese oxide deposits near could begin. We had two nylon straps specially Socorro and Deming, but no significant man- made to support the copper and to prevent (Location 7 on the index map) ganese mineralization is apparent in the Iron damage to the natural color during the lift. A The Iron Hill district is located on the west flank Hill district. single 20-ton hydraulic jack was used to lift the of the low hills in the southwestern Robledo The hematite bodies replace sections of Penn- copper high enough to slide the straps under- Mountains in Doña Ana County. The district is sylvanian limestone of the Magdalena series, neath. Then the U.S. Army Corps of Engineers’ approximately 3 mi southwest of Robledo which dip to the southeast approximately 20°. 1 barge and crane were used to lift the boulder Mountain, and is in the NW ⁄4 sec. 16 T22S R1W. The orebodies are lenticular and appear to be from where it had been resting for thousands of The latitude and longitude of the center of the related to fissure zones that cut across the bed- years. district is 32° 23' 51"N, 106° 57' 00"W. Adits and ding of the limestone in various directions. Six- The state-owned boulder now resides in the prospect pits of the Iron Hill district are readily teen bodies of hematite have been opened up, historic Quincy mine 1894 hoist house just north visible on the Leasburg, New Mexico quadran- and many other outcrops have not been of Hancock, Michigan, and will be curated by gle. explored. The dimension of the bodies varies, the A. E. Seaman Mineral Museum. It is the The district is not directly accessible by any from small masses to large bodies as much as largest piece of natural native metal ever recov- roads or trails. It is best reached by taking Inter- 200 ft long, 120 ft wide, and of unknown vertical ered from a body of water and resides on prob- state 10 to Road C 9 and a dirt road that exits extent. Dunham indicated that a moderate ably the largest hydraulic mineral display stand Road C 9 to the north, which parallels the north- resource of iron was available, but the remote- in the world! Hopefully, its final destination will south trend of the Robledo Mountains. The ness of the deposits and their distance to mar- be in the main foyer of the new museum to be mines are approximately 2 mi east of the dirt kets made them uneconomic to mine. November 2002, Volume 24, Number 4 NEW MEXICO GEOLOGY 131 The deposits are reported to be mineralogical- These days the mines of Socorro Peak beckon some geochemical evidence, that the green color ly similar to the hematite deposits of West Cum- to the mineral collector, but access to the mines of smithsonite is due to copper, the yellow to berland and the Forest of Dean, England, which is only possible through the written approval of cadmium, and the blue to cobalt. However, until are known for “kidney ore” hematite. Like these the Energetic Materials Research Test Center now, no one has used modern microchemical deposits in England, the Iron Hill district (EMRTC), an affiliate of the New Mexico Insti- studies to investigate the chromophores in formed in Carboniferous limestones that were tute of Mining and Technology. With the smithsonite. formerly overlain by a great thickness of “red approval of EMRTC, I was able to visit the fol- The Kelly mine sample exhibits strong color bed” deposits. The red beds may have provided lowing Socorro Peak mines in preparation for banding that corresponds to a change in solid hematite cement that leached and subsequently this presentation: May Flower, Socorro (Woods) solution of copper carbonate (CuCO3) in the precipitated into the underlying limestones. Tunnel, Silver Bar, Dewey Load, Merritt, Tor- smithsonite, with higher CuCO3 contents (as Fourteen short tunnels are reported in the rance, and the Maine Tunnel. In most cases, haz- much as 3.0 wt %) occurring in the strongly col- hills, and there are many shallow shafts. The ardous underground conditions, vertical shafts, ored green bands. No mineral inclusions occur dumps are loaded with excellent specimens of and collapsed drifts prevent underground in this sample, and there is little variation of the botryoidal hematite, and collecting is easy once inspection and collecting, but the mine dumps other minor elements present (calcium and you get to the mines. The mines are easily spot- can produce most, if not all, of the minerals of lead). Therefore we believe that copper is the ted on the hillsides because the dumps are a dis- interest to collectors (primarily microminerals). coloring agent in the green smithsonite from the tinct dark red against the outcrops of light-gray Minerals collected during this investigation Kelly mine. limestone. include: mottramite, mimetite, vanadinite, “Cadmian” smithsonite from the Hanover Reference wulfenite, willemite, hemimorphite, bromar- mine contains inclusions of pyrite (FeS2) ~300 Dunham, K. C., 1935, reprinted 1980, The geology gyrite/chlorargyrite, barite, malachite, cerus- µm on a side, iron-rich sphalerite or [(Zn,Fe)S], of the Organ Mountains; part III—the mines and site, chrysocolla, calcite, quartz, and gypsum. and either hexagonal greenockite or isometric mineral resources of Doña Ana County: New Caledonite, descloizite, and linarite (Moats, hawleyite (CdS). The CdS occurs in brightly col- Mexico Bureau of Mines and Mineral Resources, 1991) and argentite/acanthite and fluorite ored bands, which are ~10 µm thick and contain Bulletin 11, pp. 248–249. (Lasky, 1932) have been reported but were not about 17 % of these ~1 µm diameter inclusions. observed. In addition, as much as 19.5 wt % iron carbonate Acknowledgments (FeCO3) is present in solid solution.