Tons Of Rock Research Articles

Reversing habitat loss: An experimental test of the interactive effects of grazing exclusion and surface rock restoration on reptile conservation

Abstract Restoring structural elements of habitats and understanding how restoration interacts with environmental factors such as grazing management can be crucial for improving conservation outcomes in agricultural landscapes. Surface rock is a structural habitat type that is critical for a range of reptile species; yet, it is often poorly managed and protected. Using a Before/After, Control/Impact (BACI) design, we experimentally quantified the response of reptiles to surface rock restoration in an agricultural landscape, and tested whether its effects interacted with livestock grazing treatments to influence various reptile diversity measures. To implement our crossed factorial design, we added approximately 50 tonnes of rock and 1 km of grazing exclusion fencing across 10 sites in south‐eastern Australia. We found increases in the number of total reptile captures, total individuals and species richness when comparing rock addition plots to non‐rock plots. There was no significant overall grazing exclusion effect or interactive effect of grazing and rock treatment on reptile measures. Synthesis and applications. Our study provides experimental evidence that surface rock addition is an effective restoration method for reptiles in agricultural landscapes. We recommend that the addition of surface rock is prioritised as a restoration tool for reptiles, and that existing surface rock areas are protected from clearing.

Role of Mg Gangue Minerals in Natural Analogue CO2 Sequestration

Abstract Mineral carbonation reactions consume CO2 and thus have the potential for the long-term fixation of atmospheric CO2. This paper explores the possibility of integrating industrial-scale carbon storage into mining operations. Ultramafic rocks are typically considered to be one the most promising rocks for carbon capture and storage owing to their high content of Mg-bearing silicate minerals, such as forsterite (Mg2SiO4) and serpentine (Mg3Si2O5(OH)4). Beyond the thermodynamic considerations showing that magnesite (MgCO3) and quartz (SiO2) form from forsterite and serpentine alteration, the degree to which CO2 is carbonated depends on the kinetics of the reaction. For industrial carbon capture and storage to be viable, reasonable carbonation efficiency has to be achieved. To this effect, the reaction rates have to be increased, which can be achieved either by increasing the reactive surface area, increasing the reaction temperature, or using reagents to drive the reactions. However, these approaches are usually energy demanding or not efficient enough. As part of its activities, the mining industry excavates tens or hundreds of million metric tons of rock per mine and in certain areas these mafic rock groups can represent a significant percentage of the waste material left on the surface. This could represent a locally important source of readily available material for carbon capture and storage if the conversion process is sufficiently efficient. To test and quantify the carbonation potential of mine waste, a sample of serpentine skarn waste rock obtained from an iron ore mine in Sweden was reacted for 60 weeks in a laboratory humidity-cell test (HCT) at 20°C. The results show the dissolution of olivine, the precipitation of serpentine, an increase in the neutralization potential of the sample, and the appearance of inorganic carbon during the 60 weeks of testing. At ambient temperatures the sluggish precipitation kinetics of secondary phases will favor the formation of more hydrous Mg silicate phases, such as serpentine (Mg3Si2O5(OH)4), in place of Mg-bearing carbonates. This reaction lowers considerably the efficiency of forsterite carbonation, as only 25% of the Mg released from forsterite dissolution to form carbonate minerals. This study aims to model the carbonation efficiency of Mg silicates through the use of models supported by laboratory testwork and taking the example of a mine site in northern Sweden. This study evaluates the reaction of CO2 with Mg-bearing silicate rocks and the demonstration that carbonation reactions occur with Mg silicate wastes consuming CO2. Consequently, weathering of waste rock may well represent an important sink for carbon in the environment.

A Joint Seismic and Space‐Based Investigation of the 2016 Lamplugh Glacier and 2017 Wrangell Mountains (Alaska) Landslides

AbstractLandslides commonly occur in areas with steep topography and abundant precipitation and pose a significant hazard to local communities. Some of the largest known landslides occur in Alaska, including several that caused local tsunamis. Many landslides may have gone undetected in remote areas due to lack of observations. Here, we develop a semiautomated workflow using both seismic and geodetic observations to detect, locate, validate, and characterize landslides in Alaska. Seismic observations have shown promise in continuously monitoring landslide occurrence, while remote sensing techniques are well suited for verification and high‐resolution imaging of landslides. We validate our procedure using the 28 June 2016, Lamplugh Glacier landslide. We also present observations of a previously unknown landslide occurred on 22 September 2017 in the Wrangell Mountains region. The Wrangell Mountains landslide generated a coherent surface wavefield recorded across Alaska and the contiguous United States. We used Sentinel‐1 Synthetic Aperture Radar and Sentinel‐2 optical imagery to map the respective mass deposit. To investigate the landslide dynamics, we inverted regional seismic surface wave data for a centroid single force failure model. Our model suggests that the Wrangell Mountains landslide lasted for about 140 s and had two subevents involving at least five distinct stages. We estimate that the landslide had displaced 3.1–13.4 million tons of rocks over a distance of ∼2 km. Our results suggest that combining seismic and geodetic observations can vastly improve the detection and characterization of landslides in remote areas in Alaska and elsewhere, providing new insights into the landslide dynamics.

The deposition of type II-S Jordan oil shale in the context of Late Cretaceous source rock formation in the Eastern Mediterranean realm. Insights from organic and inorganic geochemistry and petrography

This study provides a detailed geochemical and petrographic investigation of 22 Upper Cretaceous Jordan Oil Shale (JOS) samples obtained from various wells distributed across Jordan. The JOS is generally characterized by high amounts of organic matter with total organic carbon (TOC) contents of 10–29 wt%, high carbonate contents of 15–75 wt%, and variable biogenic SiO2 contents of 1–50 wt%. The organic matter is oil-prone, reflected by a clear predominance of liptinite macerals and Rock-Eval Hydrogen Index (HI) values of 608–1078 mg HC/g TOC. In terms of elemental composition, bulk and molecular organic geochemistry and petrology, the JOS is similar to other age-equivalent organic-rich rocks from the Eastern Mediterranean. Primary bioproductivity was probably controlled by a Late Cretaceous upwelling event that affected the whole region. Low Pr/Ph ratios <0.5 indicate that organic matter preservation was not only controlled by the formation of an upwelling-related oxygen minimum zone but also by further oxygen depletion in isolated sub-basins. This setting led to vulcanization of kerogen; proven by a positive correlation between calculated organic sulfur contents and the amount of thiophenes generated during Curie-point pyrolysis. Although the thermal maturity is low (Tmax values < 430°C), significant amounts of hydrocarbons (up to 30 kg HC per ton of rock) are present within these rocks. The present bitumen fraction shows high concentrations of asphaltenes (10–65%) and NSO compounds (30–85%) with higher contributions in samples with the lowest thermal maturities. The relative contributions of aliphatic and aromatic compounds are correspondingly low, but increase with higher thermal maturities. Kinetic parameters suggest that isothermal pyrolysis at 350°C might be already enough to artificially convert 80% of the reactive kerogen within about one day, making the JOS a potential target for oil shale retorting.

Bernard Bailyn's Barbarous Modernity

Bernard Bailyn's Barbarous Modernity

ANALYSIS ON THE CONTENT OF RARE-EARTH ELEMENTS OF THE COAL DUMP “HEROIV KOSMOSU” WITH FURTHER PROSPECTS OF BIOLEACHING

Development of alternative energy sources are increasing now, but the use of minerals still plays an important role in the industrial sector, and Ukraine is no exception. DTEK Energo is a key player in Ukraine's coal industry. 13 mines and 4 coal concentrators represent production capacities of this segment. Dumps and sludge storages contain about 1.3 billion tons of rocks with an annual replenishment of about 60 million tons. These areas occupy large areas and require reclamation in the future. This paper presents the results of physico-chemical analysis of DTEK SU "Heroiv Kosmosu" coal mining dump, namely such indicators as: pH and electrical conductivity of the substrate (EC), nutrient content, concentration of rare earth elements. The results of the obtained data in the future allow to choose the best method of reclamation, involving plants, with subsequent bioleaching of rare earth metals.

ARPA–E explores paths to emissions-free metal making

The agency is seeking advice from industry and academia on how to make mining, smelting, and remediation less polluting and more energy efficient.

Mineral carbonation with thermally activated serpentine; the implication of serpentine preheating temperature and heat integration

In this paper, heat integration was coupled with serpentine preheating temperature optimization and was for the first time applied to a mineral carbonation process. For this, a process was selected with the aim to minimise its heat demand. Aspen® Energy Analyzer software was used for heat integration with pinch analysis. The mineral carbonation plant considered here processes 100 tonnes of serpentine per hour, with Mg content of 237 kg per tonne of rock, corresponding to 0.88 million tonnes per year to treat 0.5 million tonnes of CO2 emitted from a cement plant. In the base case considered for heat integration, 50% of the serpentine magnesium content was converted to hydromagnesite using 30% of the flue gas CO2 which means that 5.85 tonnes of rocks were required to capture 1 tonne of CO2.The serpentine preheating temperature, was optimized as 400 °C. Application of heat integration at this solid preheat temperature reduced the process heat demand by 25% compared to our previous study, as 5.0 GJ per tonne of CO2 captured or 9.5 GJ per tonne of CO2 avoided. This corresponds to 0.86 GJ per tonne of ore as the process heat demand was only attributed to the mineral activation. In addition, the impact of process parameters including the solid-liquid ratio and the dissolution reaction extent on the heat integration strategy was evaluated. It was found that solids concentrations as low as 5% substantially reduced the sequestration efficiency as the process waste heat was not sufficient at the optimized solid preheat temperature. Furthermore, the uncertainty behind unknown parameters such as activated serpentine heat capacity and solid heat transfer coefficient was evaluated to validate the study.

Capturing and Reusing CO2 by Converting It To Rocks

Within Earth’s surface, there are billions of tons of rocks containing minerals that are reactive with CO2, which is a greenhouse gas that has harmful effects on our planet’s climate. Over thousands of years, these minerals interact with the CO2 in the air, converting the gas into new carbonate minerals and permanently storing the CO2 in a solid form. Today, as society develops solutions to combat the harmful effects of excess CO2 in our atmosphere, the processes carried out by these reactive minerals could present a valuable opportunity. There is a challenge of speeding up the reactions so they happen within days (or even weeks), rather than thousands of years. Climate solutions like this are still new and will require more young and enthusiastic minds to advance their development so our climate is livable for generations to come!

Enhanced Kinetic Impactor for Deflecting Large Potentially Hazardous Asteroids via Maneuvering Space Rocks

Asteroid impacts pose a major threat to all life on Earth. The age of the dinosaurs was abruptly ended by a 10-km-diameter asteroid. Currently, a nuclear device is the only means of deflecting large Potentially Hazardous Asteroids (PHAs) away from an Earth-impacting trajectory. The Enhanced Kinetic Impactor (EKI) concept is proposed to deflect large PHAs via maneuvering space rocks. First, an unmanned spacecraft is launched to rendezvous with an intermediate Near-Earth Asteroid (NEA). Then, more than one hundred tons of rocks are collected from the NEA as the EKI. The NEA can also be captured as the EKI if the NEA is very small. Finally, the EKI is maneuvered to impact the PHA at a high speed, resulting in a significant deflection of the PHA. For example, to deflect Apophis, as much as 200 t of rocks could be collected from a NEA as the EKI based on existing engineering capabilities. The EKI can produce a velocity increment (∆v) of 39.81 mm/s in Apophis, thereby increasing the minimum geocentric distance during the close encounter in 2029 by 1,866.93 km. This mission can be completed in 3.96 years with a propellant cost of 2.98 t. Compared with a classic kinetic impactor, the deflection distance can be increased one order of magnitude. The EKI concept breaks through the limitation of the ground-based launch capability, which can significantly increase the mass of the impactor. We anticipate that our research will be a starting point for efficient planetary defense against large PHAs.

Evaluation of the Gas Content in Archived Shale Samples: A Carbon Isotope Study

We examined 14 archived samples of shale for the chemical and 13C isotopic composition of residual gases produced as part of rock-crushing operations at a hammer mill. Results were compared with data on maturity from Rock-Eval pyrolysis and vitrinite reflectance measurements. The samples originated from three different formations (Mikulov Marls, Ostrava Formation, and Liteň Formation) located in the Czech Republic. For comparison, we examined a gas-prone shale sample from the Polish Silurian. We used changes in the chemical and isotopic composition of released gases to evaluate the isotope fractionation during gas loss and retroactively calculated the initial content of gas in the shale samples. The gas content estimates (in L of gas per ton of rock) correspond with the maturity parameters of the shales. Calculated isotope fractionation for the gas release was −3‰ for both methane and ethane. The archived samples primarily lost methane (up to 90%), with subsequent changes in the content of ethane and higher hydrocarbon levels.

The 2015 landslide and tsunami in Taan Fiord, Alaska

Glacial retreat in recent decades has exposed unstable slopes and allowed deep water to extend beneath some of those slopes. Slope failure at the terminus of Tyndall Glacier on 17 October 2015 sent 180 million tons of rock into Taan Fiord, Alaska. The resulting tsunami reached elevations as high as 193 m, one of the highest tsunami runups ever documented worldwide. Precursory deformation began decades before failure, and the event left a distinct sedimentary record, showing that geologic evidence can help understand past occurrences of similar events, and might provide forewarning. The event was detected within hours through automated seismological techniques, which also estimated the mass and direction of the slide - all of which were later confirmed by remote sensing. Our field observations provide a benchmark for modeling landslide and tsunami hazards. Inverse and forward modeling can provide the framework of a detailed understanding of the geologic and hazards implications of similar events. Our results call attention to an indirect effect of climate change that is increasing the frequency and magnitude of natural hazards near glaciated mountains.

Insights into the Great Australian Bight gained through marine geology and benthic ecology studies

While the Great Australian Bight (GAB) represents one of the most prospective deep water basins in Australia, its vast geographic extent and deep sedimentary sequences remain poorly characterised. Recently, multidisciplinary research has been conducted to better characterise the continental and abyssal slope of the Ceduna Sub-basin. The Great Australian Bight Deepwater Marine Program (GABDMP) aimed to build a regional understanding of the deep water GAB marine geology and benthic ecology. This three-year research program encompassed four research voyages that aimed to sample and characterise deep water outcropping facies, volcanic seamounts, potential seeps and their associated biological communities. These voyages used a variety of equipment to achieve the research goals and included the deployment of autonomous underwater and remotely operated vehicles and a seafloor coring system. Numerous sites across the Ceduna Sub-basin from 700 to 5501 m water depth were studied. Sampling operations collected over 2.8 tons of rocks, 148 m of core, 55 698 biological specimens and 48 097 km2 of mapping data. Nearly 4000 geological samples have been analysed to date. This paper will summarise the key findings from the GABDMP and the geological and biological insights that have been revealed through this multidisciplinary research program.

Does Tungsten Availability Control the Presence of Tungsten In Turbidite-Hosted Orogenic Gold Mineralization? Evidence From the Meguma and Bendigo-Ballarat Terranes

Turbidite-hosted orogenic Au deposits are commonly enriched in W, along with a variety of other trace elements. A mineralogical source for W has recently been shown in the Otago Schist of southern New Zealand (Cave et al. 2016), with detrital rutile in the metasedimentary rocks recrystallizing to metamorphic titanite and making W available to be mobilized from the rock mass. In this study, we investigate the availability of W through prograde metamorphic mineral recrystallization in two additional turbidite-hosted orogenic Au provinces, one containing orogenic Au mineralization with associated subordinate W (Meguma Terrane, Canada), and the other containing orogenic Au mineralization without associated W (Bendigo-Ballarat Terrane, Australia). This was undertaken to assess whether W availability during prograde metamorphism is a key process in controlling the presence of W in turbidite-hosted orogenic Au mineralization. Like the Otago Schist, in both terranes detrital rutile is identified as being the most important host mineral for W in the lowest metamorphic grade rocks, and its prograde metamorphic recrystallization (to ilmenite) makes significant amounts of W available for mobilization (0.65 and 1.85 g of W per tonne of rock from the Goldenville and Halifax groups of the Meguma Terrane, respectively, and 0.16 g of W per tonne of rock from the Castlemaine Group of the Bendigo-Ballarat Terrane). This release of W in the Meguma Terrane is likely the source of W in these orogenic Au deposits. The lack of W in the orogenic Au deposits of the Bendigo-Ballarat Terrane suggests that W availability is not the only process controlling the presence of W minerals in turbidite-hosted orogenic Au mineralization. Alternatively, it might reflect a lower greenschist facies metasedimentary (Castlemaine Group) source for these deposits (i.e., a lower metamorphic grade source than the rutile to ilmenite conversion), as has been previously suggested.

A Simple System Dynamics Model for the Global Production Rate of Sand, Gravel, Crushed Rock and Stone, Market Prices and Long-Term Supply Embedded into the WORLD6 Model

A model for global supply of sand, gravel and cut stone for construction based on a system dynamics model was developed for inclusion in the WORLD6 model. The Sand-Gravel-Stone model simulates production and market supply, demand and price for natural sand and gravel, sand and gravel from crushed rock and cut stone. The model uses market mechanisms where the demand is depending on population size, maintenance and price. For the period 2000–2050, the WORLD6 model outputs correlate with the GINFORS model outputs (r 2 = 0.98), but they may take different pathways after 2050. The resources of sand and gravel are estimated at 12 trillion ton each, another 125 trillion tons of rock is suitable for crushing to sand and gravel and at least 42 trillion ton of quality stone is available for production of cut stone. The simulation, under assumed business-as-usual conditions, shows that cut stone production will reach a maximum level by about 2020–2030 and stabilize after that. The cause for this is that demand exceeds extraction as well as slow exhaustion of the known reserves of high-quality stone. Sand and gravel show plateau behaviour and reach their maximum production rate in 2060–2070. The reason for the slight peak towards a plateau behaviour is partly driven by an expected population decline and increasing prices for sand and gravel, limiting demand. Assuming business-as-usual conditions rates remain at that level for centuries.

Key Performance Indicators for Electricity Conservation in Open Pit Mining

In mining operation, blasts are used to fracture the in-situ rock mass and prepare it for excavation, crushing and grinding. The High-energy blasting, which uses increased amount of explosive material per tonne of rock, is considered to be one of most effective ways to reduce the consumption of energy in the milling process, resulting production saving as well as reduction in dust (PM5) and tailing. In this article, the main focus is to investigate the electrical intensity of the five grinding lines in the mill, as they accounted for the majority of site electricity consumption, in relations to other operational procedures, in particular the high-energy blasting. Several regression models were established, the data points were fitted within 10% of the actual values, and the majority within 5%. The models provide management better ways to predict and target electrical consumption and environmental impact.

Comprehensive evaluation of high-steep slope stability and optimal high-steep slope design by 3D physical modeling

Abstract High-steep slope stability and its optimal excavation design in Shuichang open pit iron mine were analyzed based on a large 3D physical simulation technique. An optimal excavation scheme with a relatively steeper slope angle was successfully implemented at the northwest wall between Nos. 4 and 5 exploration lines of Shuichang Iron Mine, taking into account the 3D scale effect. The physico-mechanical properties of rock materials were obtained by laboratory tests conducted on sample cores from exploration drilling directly from the iron mine. A porous rock-like composite material was formed for the model, and the mechanical parameters of the material were assessed experimentally; specifically, the effect of water on the sample was quantitatively determined. We adopted an experimental setup using stiff modular applied static loading to carry out a visual excavation of the slope at a random depth. The setup was equipped with acoustic emission (AE) sensors, and the experiments were monitored by crack optical acquirement, ground penetrating radar, and close-field photogrammetry to investigate the mechanisms of rock-mass destabilization in the high-steep slope. For the complex study area, the model results indicated a clear correlation between the model’s destabilization resulting from slope excavation and the collected monitoring information. During the model simulation, the overall angle of the slope increased by 1–6 degrees in different sections. Dramatically, the modeled excavation scheme saved over 80 million tons of rock from extraction, generating enormous economic and ecological benefits.

Determining the radon exhalation rate from a gold mine tailings dump by measuring the gamma radiation

The mining activities taking place in Gauteng province, South Africa have caused millions of tons of rocks to be taken from underground to be milled and processed to extract gold. The uranium bearing tailings are placed in an estimated 250 dumps covering a total area of about 7000 ha. These tailings dumps contain considerable amounts of radium and have therefore been identified as large sources of radon. The size of these dumps make traditional radon exhalation measurements time consuming and it is difficult to get representative measurements for the whole dump.In this work radon exhalation measurements from the non-operational Kloof mine dump have been performed by measuring the gamma radiation from the dump fairly accurately over an area of more than 1 km2. Radon exhalation from the mine dump have been inferred from this by laboratory-based and in-situ gamma measurements. Thirty four soil samples were collected at depths of 30 cm and 50 cm. The weighted average activity concentrations in the soil samples were 308 ± 7 Bq kg−1, 255 ± 5 Bq kg−1 and 18 ± 1 Bq kg−1 for 238U, 40K and 232Th, respectively. The MEDUSA (Multi-Element Detector for Underwater Sediment Activity) γ-ray detection system was used for field measurements.The radium concentrations were then used with soil parameters to obtain the radon flux using different approaches such as the IAEA (International Atomic Energy Agency) formula. Another technique the MEDUSA Laboratory Technique (MELT) was developed to map radon exhalation based on (1) recognising that radon exhalation does not affect 40K and 232Th activity concentrations and (2) that the ratio of the activity concentration of the field (MEDUSA) to the laboratory (HPGe) for 238U and 40K or 238U and 232Th will give a measure of the radon exhalation at a particular location in the dump. The average, normalised radon flux was found to be 0.12 ± 0.02 Bq m−2 s−1 for the mine dump.

Robert Smithson's Environmental History

Like all the other artists credited with inventing American land art – among them Walter De Maria, Michael Heizer, Nancy Holt, Joan Jonas, Robert Morris, and Dennis Oppenheim – Robert Smithson initially sought a latitude beyond the New York gallery system. Marcel Duchamp and Robert Rauschenberg had earlier claimed to be working in the gap between art and life, but their ready-mades and assemblages were basically a half-measure that could never be perceived as art outside the gallery or museum. When Smithson crossed the Hudson River to explore the abandoned air-strips, quarries, and ‘manmade geological networks’ of suburban New Jersey, eventually heading even farther west to design The Spiral Jetty (1970), he sought to create beauty and meaning in a space which had traditionally been considered exterior to the sphere of art altogether – a non-space, so to speak, or a ‘low-profile’ space, that also negated the conventional art object.1 Brian Wallis has noted that the effort to dismantle or move beyond the gallery system resulted in ‘a whole host of practices designed to break down the object’ – including ‘negation (cuts, holes, removals); duration (space as a factor of time); decay (decomposition of organic and inorganic materials); replacement (transfer of materials from one context to another)’; and ‘dispersion (patterns produced by gravity in the form of spills, pours, slides, etc.)’.2The Spiral Jetty was a perfect example of the displaced object. It was located on the shores of the Great Salt Lake in Utah, it was constructed by transferring tons of rock from one place to another, and it deliberately linked space to time by allowing for both the temporary submersion of the jetty and the possibility that it might sooner or later be completely encrusted by salt crystals.3

Carbon Dioxide Efficiency of Terrestrial Enhanced Weathering

Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimistic scenarios. The results show that the choice of source rocks and material comminution technique dominate the CO2 efficiency of enhanced weathering. CO2 emissions from transport amount to on average 0.5-3% of potentially sequestered CO2. The emissions of material mining and application are negligible. After accounting for all emissions, 0.5-1.0 t CO2 can be sequestered on average per tonne of rock, translating into a unit cost from 1.6 to 9.9 GJ per tonne CO2 sequestered by enhanced weathering. However, to control or reduce atmospheric CO2 concentrations substantially with enhanced weathering would require very large amounts of rock. Before enhanced weathering could be applied on large scales, more research is needed to assess weathering rates, potential side effects, social acceptability, and mechanisms of governance.