The Acropolitan - v. 5, no. 4

In this issue...Debate Team, K. C. Gym, Constitution, John F. Rickards, Coach McAuliffe, Mines Basketball, Bureau of Mines, Butte, Montana

The Acropolitan - v. 6, no. 1

In this issue...Francis A. Thomson, registration, Chequamegon Cafe, Butte, Montana, M club, Mines Tennis Club, Sigma RHO, Chester H. Steele, Diamond Mine

The Acropolitan - v. 7, no. 1

In this issue...Senior Geology Trip, Mine Ventilation, Wein's Men's Store, Mines Football, Creamery Café, Butte High School Auditorium, Mr. Adam Puffer

The Acropolitan - v. 7, no. 2

In this issue...Dr. Coolbaugh, Montana Society of Engineers, Leonard Hoist House, Dancing Club, copper, Boulder Batholith, gold, Butte, Montana

The Acropolitan - v. 7, no. 3

In this issue...Mines Athletics, Co-ed Club, Faculty Lunch, Anderson Carlisle Society, The Lockwood, Butte, Montana, Mining Engineers, Professor A. M. Gaudin

The Acropolitan - v. 7, no. 4

In this issue...Dr. C. H. Clapp, Montana State Bureau of Mines, poetry, Al's Photo Shop, Butte, Montana, Intercollegiate Track Meet, Normal College

The Acropolitan - v. 7, no. 5

In this issue...M Club Dance, Rabbi Emanuel Sternheim, Women's Athletic Association, Men's Smoker, Gamer's Café, Anaconda Copper Mining Company

The Acropolitan - v. 7, no. 6

In this issue...Rocky Mountain Garden Club, Big Butte, M Days, Butte Montana, Salt Mine, Walker's Café, Tex Rickard, State Oratory Contest, Frank Moran

The Acropolitan - v. 8, no. 1

In this issue...A. M. Gaudin, swim marathon, Creamery Café, Anaconda, Montana, Ore Dressing, copper, Argentina maps, Dr. C. W. Clapp, Glacier Park, Dancing Club

The Acropolitan - v. 8, no. 2

in this issue...Annie Anderson, Hecla MIne, F. A. Thomson, Anaconda Copper Mining Company, Sigma RHO, Mines football, Montana State University

The Acropolitan - v. 8, no. 4

In this issue...School of Mines Librarian, Margery Bedinger, Kiwanis, Medlin's Pharmacy, Commencement, Poser-Badger case, Mr. Chester Steele, Map Interpretation class

The Acropolitan - v. 8, no. 3

In this issue...Doris Torongo, Montana Fossils, President Hoover, Mine Rescue, First Aid, Radio Debate, Anaconda Smelter, nickel-copper alloy, Ore Diggers basketball

The Acropolitan - v. 3, no. 3

In this issue...Anderson Carlisle Club, Mines Smoker, Rotary and Exchange Club, Kiwanis Club, Forestry policies, Elbert Hubbard, Rosenstein Brothers

Geochemistry and Stable Isotopes of Surface Water and Groundwater in the Continental Pit in Butte, Montana, USA

The Continental porphyry Cu‐Mo mine, located 2 km east of the famous Berkeley Pit lake of Butte, Montana, contains two small lakes that vary in size depending on mining activity. In contrast to the acidic Berkeley Pit lake, the Continental Pit waters have near-neutral pH and relatively low metal concentrations. The main reason is geological: whereas the Berkeley Pit mined highly‐altered granite rich in pyrite with no neutralizing potential, the Continental Pit is mining weakly‐altered granite with lower pyrite concentrations and up to 1‐2% hydrothermal calcite. The purpose of this study was to gather and interpret information that bears on the chemistry of surface water and groundwater in the active Continental Pit. Pre‐existing chemistry data from sampling of the Continental Pit were compiled from the Montana Bureau of Mines and Geology and Montana Department of Environmental Quality records. In addition, in March of 2013, new water samples were collected from the mine’s main dewatering well, the Sarsfield well, and a nearby acidic seep (Pavilion Seep) and analyzed for trace metals and several stable isotopes, including dD and d18O of water, d13C of dissolved inorganic carbon, and d34S of dissolved sulfate. In December 2013, several soil samples were collected from the shore of the frozen pit lake and surrounding area. The soil samples were analyzed using X‐ray diffraction to determine mineral content. Based on Visual Minteq modeling, water in the Continental Pit lake is near equilibrium with a number of carbonate, sulfate, and molybdate minerals, including calcite, dolomite, rhodochrosite (MnCO3), brochantite (CuSO4·3Cu(OH)2), malachite (Cu2CO3(OH)2), hydrozincite (Zn5(CO3)2(OH)6), gypsum, and powellite (CaMoO4). The fact that these minerals are close to equilibrium suggests that they are present on the weathered mine walls and/or in the sediment of the surface water ponds. X‐Ray Diffraction (XRD) analysis of the pond “beach” sample failed to show any discrete metal‐bearing phases. One of the soil samples collected higher in the mine, near an area of active weathering of chalcocite‐rich ore, contained over 50% chalcanthite (CuSO4·5H2O). This water‐soluble copper salt is easily dissolved in water, and is probably a major source of copper to the pond and underlying groundwater system. However, concentrations of copper in the latter are probably controlled by other, less‐soluble minerals, such as brochantite or malachite. Although the acidity of the Pavilion Seep is high (~ 11 meq/L), the flow is much less than the Sarsfield Well at the current time. Thus, the pH, major and minor element chemistry in the Continental Pit lakes are buffered by calcite and other carbonate minerals. For the Continental Pit waters to become acidic, the influx of acidic seepage (e.g., Pavilion Seep) would need to increase substantially over its present volume.

The Solubility of Zinc Ethyl Xanthate in Water

A determination of the solubility of zinc ethyl xanthate was attempted by measuring the refractive index of a saturated solution of that salt. The small increment in refractive index effected by adding zinc ethyl xanthate to water in saturation quantities rendered measurements difficult and of dubious accuracy.