Homestake Gold Mine Research Articles

Isolation and characterization of cellulose-degrading bacteria from the deep subsurface of the Homestake gold mine, Lead, South Dakota, USA

The present study investigated the cultivable mesophilic (37 degrees C) and thermophilic (60 degrees C) cellulose-degrading bacterial diversity in a weathered soil-like sample collected from the deep subsurface (1.5 km depth) of the Homestake gold mine in Lead, South Dakota, USA. Chemical characterization of the sample by X-ray fluorescence spectroscopy revealed a high amount of toxic heavy metals such as Cu, Cr, Pb, Ni, and Zn. Molecular community structures were determined by phylogenetic analysis of 16S rRNA gene sequences retrieved from enrichment cultures growing in presence of microcrystalline cellulose as the sole source of carbon. All phylotypes retrieved from enrichment cultures were affiliated to Firmicutes. Cellulose-degrading mesophilic and thermophilic pure cultures belonging to the genera Brevibacillus, Paenibacillus, Bacillus, and Geobacillus were isolated from enrichment cultures, and selected cultures were studied for enzyme activities. For a mesophilic isolate (DUSELG12), the optimum pH and temperature for carboxymethyl cellulase (CMCase) were 5.5 and 55 degrees C, while for a thermophilic isolate (DUSELR7) they were 5.0 and 75 degrees C, respectively. Furthermore, DUSELG12 retained about 40% CMCase activity after incubation at 60 degrees C for 8 h. Most remarkably, thermophilic isolate, DUSELR7 retained 26% CMCase activity at 60 degrees C up to a period of 300 h. Overall, the present work revealed the presence of different cellulose-degrading bacterial lineages in the unique deep subsurface environment of the mine. The results also have strong implications for biological conversion of cellulosic agricultural and forestry wastes to commodity chemicals including sugars.

Deep underground lab design team picked

The U.S. National Science Foundation (NSF) announced on 10 July 2007 the selection of a University of California‐Berkeley proposal to produce a technical design for a U.S. Deep Underground Science and Engineering Laboratory (DUSEL) at the former Homestake gold mine near Lead, S.D. NSF also will begin working with researchers to identify initial experiments that might be deployed in DUSEL, according to Tony Chan, assistant director for NSF's Directorate of Mathematical and Physical Sciences.NSF concurred with a panel of external experts who had determined that the proposal offered the greatest potential for developing a DUSEL. Any decision to construct and operate this laboratory needs further approvals by NSF and the U.S. National Science Board. An interdisciplinary “deep science” laboratory could shield sensitive physics experiments from background activity and could provide scientists with direct access to geological structures, tectonic processes, and life forms that are best studied deep underground. A Homestake DUSEL, if built as envisioned by its supporters, would be the largest and deepest facility of it kind in the world.

South Dakota Digs In

One state made a preemptive move this week in the competition to host the proposed $300 million national Deep Underground Science and Engineering Laboratory (DUSEL) ( Science , 29 July, p. [682][1]). South Dakota announced it has struck a deal to open the upper levels of the abandoned Homestake gold mine in Lead as soon as 2007 as an interim underground laboratory. The National Science Foundation (NSF) is currently deliberating whether to build DUSEL at Homestake or at the Henderson Mine in Empire, Colorado. South Dakota Governor Mike Rounds, a Republican, says scientists have an “open invitation” to use the space, which at 1500 meters deep would be the second deepest lab in the world. “We're available, and the resources are there,” Rounds says. But Henderson bid spokesperson Chang Kee Jung, a physicist at Stony Brook University in New York, called the move “not kosher.” He fears that a working lab would hand NSF what amounts to a fait accompli, as well as put the foundation in a tough position if a researcher were to propose work at Homestake before a DUSEL decision is finalized. NSF says it will maintain its standards during the DUSEL process. [1]: /lookup/doi/10.1126/science.309.5735.682a

Underground science research facilities in the United States, the transition from mine tenant to facility operator

The underground physics research community (UPRC) in the United States has historically conducted research in underground mines. Because underground mines exist for the purposes of ore extraction, research activities sometimes take a secondary role. Underground science has matured, as second and third generation experiments have demonstrated the continuing benefit of such research. Success breeds interest, so the demand for underground research space has increased. Hence the need for a dedicated underground laboratory has been recognized and pursued. Underground physics research in the United States began with several cosmic ray studies in the 1950s. In the 1960s, future Nobel Prize winner Fred Reines and his associates observed cosmic-ray produced neutrinos at the famous East Rand Proprietary Gold Mine near Johannesburg, South Africa. The first large-scale US detector was located at the Homestake gold mine in Lead, South Dakota. The detector was a 380,000-liter tank of perchloroethylene, a cleaning fluid. Subsequent experiments included: the water Cerenkov detector for the Irvine-Michigan-Brookhaven (IMB) experiment, located 600 m underground in the Morton salt mine near Cleveland, OH; the Harvard-Purdue-Wisconsin (HPW) experiment 650 m underground in Park City, UT; and the Soudan 2 proton decay experiment located 713 m underground at the Soudan Underground Mine State Park in northeastern Minnesota. International underground physics laboratories include: Gran Sasso, Pyhasalmi mine, Kamioka Mozumi mine, Sudbury Neutrino Observatory at the INCO Creighton mine, and the Boulby mine. The underground physics research community in the US is pursuing a sole-purpose National Underground Science Laboratory. Candidate sites are: Homestake mine, Mount San Jacinto, Soudan mine, WIPP site and the Henderson mine. The next-generation nucleon decay experiment, tentatively called UNO, will require a cavern 60 m wide by 60 m high by 180 m long at a depth on the order of 1,500 m. The transition from a single experiment facility to a multiple experiment facility requires development of a separate operating authority. The authority must deal with the new institutional issues associated with balancing the laboratory versus experiment issues, including different sources of funding, shared responsibilities and liabilities, experiment rights and conflict resolution, decommissioning, and provided services. In all inhabitable building spaces, whether above- or underground, providing fire and life safety is the most important design requirement. For the underground science laboratories, this must be accomplished in the underground environment, and in the framework of several mining, occupational and building codes. The underground environment, while inhospitable in some ways, is a necessity for current and future high-energy physics research. Deep underground space can be developed to make regular human occupation safe, functional and appealing. The benefits are clear for a single-purpose underground facility, where underground science is the sole reason for being underground. Sites for an US National Underground Science Laboratory are many and varied. The challenge remains to develop and fund the best site. (A). Reprinted with permission from Elsevier. For the covering abstract see ITRD E124500.

3-D tomographic imaging of anomalous stress conditions in a deep US gold mine

In an effort aimed at locating highly stressed and destressed areas that may influence rockbursts, the US Bureau of Mines conducted an active 3-D seismic tomographic investigation between the 7100 and 7250 levels (2165 m to 2210 m depth) of the Homestake gold mine, Lead, South Dakota. Existing rock bolts were used to mount geophones and as strike points for introducing seismic energy (nominally 750 Hz) using an 8-lb sledge hammer. Approximately 2900 compressional wave travel time measurements were recorded spanning up to 155 m between drifts at several levels. Eight different reconstructions, computed using different uniform starting models, were averaged together to produce a robust final velocity model. The average velocity tomogram portrayed a heterogeneous structure (3–6.8 km/s). Regions of low-velocity correlated with known locations of drifts, stopes, ore shoots, and rockburst damage, while high-velocity regions were indicative of elevated levels of compressional stress. 3-D isoprobability surfaces were used to assess the degree of risk associated with anomalous regions; significant risk zones appeared adjacent to backfilled slopes and at the center of pillars indicating the likelihood of concentrated stress.

The International Germanium Experiment (IGEX) in 1993

The data collected from the first set of three IGEX enriched germanium detectors have been analyzed. The best background obtained was less than 0.3 counts/keV/kg/y near 2 MeV, obtained in the Homestake gold mine in Lead, SD, USA. Data combined from all the detectors yield T 1 2 0τ ≥ 1.0 × 10 24 y (90% CL) . The first detector produced in the second phase of the experiment is a 2.15 kg germanium crystal of 2.16 keV FWHM at 1332 keV. Several experiences with the first group of detectors have led to improvements in the mechanical design of the copper cryostat. Also, low background materials research done in the last two years has lowered the specific activity of the electroformed copper. The new detector is currently operating in the Homestake gold mine.

Simulated progress in double-beta decay

A Monte Carlo code has been developed to accurately simulate double-beta decay measurements. Coincident gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete 100Mo nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra obtained in the Homestake gold mine in Lead, SD, for the purpose of extremely sensitive materials assay for the construction of new, large, enriched germanium detectors. Assays as low as 9 μBq/g of 210Pb in lead shielding were obtained.

Confirmation of the observation of 2v ββ decay of 76Ge

Two previous independent reports of 2v ββ decay by the ITEP-YPI Collaboration, T 1 2 2 v = (9±1) × 10 20 yr (1σ) , and the PNL-USC Collaboration, T 1 2 2 v = (1.12 −0.26 +0.48) × 10 21 yr (2σ) , are confirmed. A 0.25 kg Ge(Li) detector, isotopically enriched to 85% in 76Ge, was operated in the PNL-USC ultralow-background facility in the Homestake gold mine. Following a single correction to the data, a spectrum resembling that observed in the earlier PNL-USC experiment, with about the same intensity per 76Ge atom per year, was observed. The measured half-life is T 1 2 2 v = (9.2 −0.4 +0.7) × 10 20 yr (2σ) .

Solar Neutrino Update: Three Detectors Tell Three Stories

For 17 years, a 600-ton vat of cleaning fluid in the bowels of a South Dakota gold mine was the only detector on Earth looking at neutrinos from the Sun. And what Raymond Davis and his colleagues at the Homestake gold mine reported year after year was very puzzling: Their long-term average capture rate from 1970 through 1985 was 0.472±0.037 solar neutrinos captured per day. But the “standard solar model” predicted, with considerable confidence, that the Homestake detector ought to be seeing about 1.8 neutrinos from the Sun per day. Allowing for the uncertainties of the standard solar model, 1.2 captures per day was the very least the theorists would find comprehensible in the light of what they thought they knew about how the Sun works.

The determination ofin situ rock thermal properties and the simulation of climate in an underground mine

This paper describes the results from a continuing research project started in 1984, which is investigating improved methods for predicting the underground climate in hot mines. The Homestake Gold Mine in South Dakota was the site for testing methods, based on radial heat flow theory, to measurein situ values of the thermal conductivity and diffusivity of rock. The methods used proved to be quite within the capability of mine staff to carry out for themselves. The results were acceptable and verified thatin situ thermal rock properties can differ considerably from laboratory determined values, in this case by a factor of approximately two. A mine climate simulation program, CLIMSIM, was applied to case studies from the Homestake mine using the measured thermal rock parameters. The results showed good correlation between the measured and simulated values.

Detection Technique: The indium solar neutrino project

Where are the missing solar neutrinos? The standard model of energy production in the sun predicts a neutrino flux more than three times that observed in the only experiment performed so far the 37CI experiment in the Homestake Gold Mine in South Dakota.

Experimental Test of Baryon Conservation: A New Limit on Neutron-Antineutron Oscillations in Oxygen

This paper reports the result of a search for baryon-number-nonconserving neutron-antineutron transitions in oxygen using a 300-ton water Cherenkov detector located in the Homestake gold mine at a depth of 4200 meters of water equivalent. The 90%-confidence-level upper limit for the neutron partial lifetime for this process is found to be 1.4\ifmmode\times\else\texttimes\fi{}${10}^{30}$ yr. According to a recent calculation of neutron-antineutron oscillations in oxygen, this result corresponds to a lower limit on the free-neutron oscillation time of 2\ifmmode\times\else\texttimes\fi{}${10}^{7}$ sec.

Multiple muons in the Homestake underground detector

The 113-${\mathrm{m}}^{2}$ water Cherenkov detector at a depth of 1480 m (4200 m water equivalent) in the Homestake Gold Mine, Lead, South Dakota, has been used to study multiple muons with ${E}_{\ensuremath{\mu}}\ensuremath{\gtrsim}2.7$ TeV produced in cosmic-ray interactions by primaries of ${10}^{14}$-${10}^{15}$ eV/nucleon. The decoherence curve and multiple-muon rates are presented.

Glacial epochs related to solar core?

A recent report by the Los Alamos National Laboratory states to the effect that terrestrial climatic changes during the past millennium, including the glacial epochs, may be related, even caused, by variations in the sun (Los Alamos Science, Summer 1982). G. Cowan and W. Haxton at Los Alamos theorize that on the basis of sunspot activity and carbon‐14 production, such a causal relation exists. Observers of the solar neutrino flux have formed experiments in deep mines to test the hypothesis. The abundances of technetium‐97 and ‐98 related to the flux are determined in a deeply buried molybdenite deposit, thus providing a geochemical record. This record, in conjunction with measurements of the solar neutrino flux (being made underground at the Homestake gold mine in South Dakota by geophysicist R. Davis of the Brookhaven National Laboratory), should provide an unequivocal test of the relationship of variations in the central temperature of the sun, or solar core, with the timing of the Pleistocene period.

Neutrino bursts from collapsing stars-results from the Homestake burst search

The 300 ton water Cerenkov detector located at a depth of 4.2 km water equivalent in the Homestake gold mine has been searching for bursts of neutrinos since late 1978. The detector has sensitivity sufficiently high to observe 10 MeV neutrinos and antineutrinos from collapsing stars releasing 1053 erg of neutrino energy at a distance of 10 kpc. No neutrino bursts have been seen over a running time of 384 days.

Solar neutrinos captured at Homestake

The nuclear fusion processes in the sun are not clearly understood, but solar geophysicists Ray Davis, of the Brookhaven National Laboratory, and Ed Fireman, of the Smithsonian Institution, are improving on physical models of solar processes by studying the solar neutrino flux. They are doing this by capturing neutrinos and analyzing them with apparatus located a mile below the earth's surface in the Homestake gold mine in South Dakota.This study has led recently to a few surprise findings related to fundamental properties of both the solar system and matter. The flux rate of solar neutrinos is closely tied to the fusion rates and thus the solar system release of energy. The rates are also a measure of the ultimate stability of matter in the universe, the ultimate loss of mass.

Experimental Test of Baryon Conservation: A New Limit on the Nucleon Lifetime

The result of a search for nucleon decay using a 300-ton water \ifmmode \check{C}\else \v{C}\fi{}erenkov detector located in the Homestake gold mine is reported. The nucleon total lifetime is found to be ${T}_{N}>3\ifmmode\times\else\texttimes\fi{}{10}^{31}{B}_{\ensuremath{\mu}}$ yr, where ${B}_{\ensuremath{\mu}}$ is the model-dependent probability for production and detection of a decaying muon following a nucleon decay event. In the SU(5) grand unified model, published calculations of ${B}_{\ensuremath{\mu}}$ vary from 5% to 10%, thereby yielding nucleon total lifetime limits in the range (1.5-3)\ifmmode\times\else\texttimes\fi{}${10}^{30}$ yr.

Cable bolting at the homestake gold mine : Schmuck, C H Min Engng, V31, N12, Dec 1979, P1677–1681

Cable bolting at the homestake gold mine : Schmuck, C H Min Engng, V31, N12, Dec 1979, P1677–1681

Possible antineutrino pulse of extraterrestrial origin

WE report an unusual event observed during our search for electron antineutrino Ve bursts of extraterrestrial origin1. Our experiment uses a deep underground Ve burst-detector station, adjacent to the Brookhaven Solar Neutrino Observatory2 at a depth of 4,400 metres water equivalent (m.w.e.) in the Homestake Gold Mine in Lead, South Dakota. At this station we have placed a number of large water Cerenkov counters (Fig. 1) designed to detect Ve interactions by the Cerenkov radiation from positrons resulting from Ve + p →n + e+ (ref. 3).

Homestake Gold Mine, South Dakota; II, Lead Isotopes, Mineralization Ages, and Source of Lead in Ores of the Northern Black Hills

For reference to part 1, see Rye, D. M., and Rye, R. O., Econ. Geol., Vol. 69, p. 293, 1974