Rock Piles Research Articles

Metamorphism of sedimentary rocks recognised by 19th century French naturalists: A case study from the Chavanon sequence marbles, Massif Central, France

The Chavanon metamorphic sequence in the Variscan French Massif Central contains marble lenses that have been exploited since at least the 18th century to produce lime. They provided an opportunity to some major pioneers among nineteenth century French geologists to understand how metamorphic rocks are formed. The intimate association between marbles and gneisses led them to propose that the initial pile of rocks was deposited as a single unit under water. They thoroughly described the attitude, folding and mineralogy of the marbles, making their works of great historical value. Originally written in French, their translation into English and the reproduction of original figures from the works they published will be very useful to the international community of geologists interested in the history of their science.

Tectono-sedimentary evolution of the Paleoproterozoic succession of the Carajás Basin, southeastern Amazonian Craton, Brazil: Insights from sedimentology, stratigraphy, and U–Pb detrital zircon geochronology

The Carajás Basin, situated in the southeastern Amazonian Craton in northern Brazil, hosts a > 6 km thick pile of volcano-sedimentary rocks deposited from the Neoarchean to the early Paleoproterozoic eras (ca. 2.75–2.06 Ga). It is claimed that this basin started as a rift configuration in which volcanic and banded iron formation strata were deposited during the Neoarchean Era. However, the tectono-sedimentary evolution of this basin through the Paleoproterozoic Era remains unexplored. Based on a sedimentological, stratigraphic, and U–Pb detrital zircon geochronological investigation of a marine to a fluvial succession of this basin, this study suggests that the Carajás Basin evolved in a foreland setting during the early Paleoproterozoic Era. Probably, the Carajás Foreland Basin was sedimented in the underfilled stage (ca. 2.5–2.3 Ga) by deep-marine strata (i.e., glaciogenic submarine fan deposits), likely from the Siderian–Rhyacian Serra Sul Formation. Subsequently, shallow-marine deposits of the Azul Formation were deposited in the filled stage (ca. 2.3–2.1 Ga), followed by deposition of the fluvial to alluvial deposits of the Águas Claras and Gorotire formations during the overfilled stage (ca. 2.1–1.9 Ga). The Azul and Águas Claras formations were supplied mainly by Meso- to Neoarchean source rocks, whereas Paleoproterozoic and Paleoarchean rocks played the role of a subordinate source of sediments. The youngest U–Pb age cluster, at ca. 2.27 Ga, is interpreted as its maximum depositional age. In terms of paleogeography, the occurrence of Rhyacian zircon grains in the Azul Formation deposits suggests, at least partially, a connection between the Carajás Protocontinent with the Bacajá Domain during that period. The integrated data corroborate the hypothesis that the foreland basin was formed in a scenario of collision between the Bacajá Domain and the Carajás Protocontinent during the Transamazonian Cycle. These dramatic upheavals are directly related to the configuration of the Columbia Supercontinent, which initially led to the emergence of the Carajás Foreland Basin, and soon after, the cratonization of proto-Amazonia

Assessing axial load transfer mechanism of open-ended tubular piles penetrating in weak rocks using three-dimensional discrete element method

In order to obtain a better understanding of the load transfer mechanism of open-ended tubular piles driven into weak rocks, numerical analysis is conducted to study the internal and external shaft frictions, base resistance and the stress distribution pattern in the surrounding rock mass. Meanwhile, since pile shoes are often applied when driving to the rock layer, a common inner pile shoe attached to the open-ended tubular pile was analysis and compared with the pile without a shoe. In this study, the discrete element method (DEM), which can mimic rock grains and the interaction between grains, is adopted due to its ability to simulate large deformation problems such as pile penetration process. The flat-joint model that allows partial damage at the contact interface was employed to replicate the discrete nature of the rock mass. The rock behaviour was calibrated against triaxial test results for a pyroclastic weak rock, and then the calibrated rock was employed for the simulation of pile penetration. A 30° segment of the true-scale model was simulated using the DEM with a height of 3 m and a radius of 1.5 m, which was composed of about 557,000 particles. Initial stresses were applied at the boundary of the testing chamber, while the side of the chamber was discretised into several sections with increasing horizontal stresses with depth to establish the at rest condition. Numerical results for penetration of an open-ended tubular pile show that the external shaft resistance of the pile with inner pile shoe increased approximately linearly as the pile penetrated deeper. In addition, the internal shaft friction was notably less than the external shaft friction for both piles with and without a shoe. Plugging was observed for both piles with and without a driving shoe. The inner pile shoe allowed the pile partial plugging to occur at shallower penetration depth. This study sheds a light on the load transfer mechanism of the open-ended tubular piles and the effect of the shoe on the axial capacity of the piles in weak rocks.

A column study of the impact of layering the different Lac Tio mine waste rock lithologies on drainage water quality

In the mining industry, the extraction of waste rocks (WR), without economic value, is needed to access ore deposits. The amount of WR are very large in the case of open pit mines. They are usually stored at the surface in waste rock piles. The presence of reactive minerals such as sulphides in waste rock can lead to the contamination of drainage water that come-out from these waste rock piles. In order to limit the production of contaminants and the volume of drainage water, an innovative method of construction of waste rock piles has been developed. In this context, an experimental waste rock pile was constructed at the Lac Tio mine near Havre-Saint-Pierre (Quebec, Canada) to evaluate the performance of this approach in field conditions. To understand the geochemical mixing between the leachate from the hemo-ilmenite and anorthosite waste rock layers constituting this experimental pile, tests using lab columns that were filled with layers of these two types of materials were run. The anorthosite and hemo-ilmenite waste rock subjected to column tests generated near-neutral drainage (pH ~7) containing up to 4.5 mg/l of nickel, and 1500 mg/l of sulphate. The nickel and sulphate release rates varied from one to two orders of magnitude depending on the type of waste rocks and their configuration (pure or mixed with each other). The drainage water quality was affected by changes in the volume of rinsing water, by the precipitation/dissolution of secondary minerals, and by Ni sorption within anorthosite waste rock. This study demonstrates that the storage of hemo-ilmenite waste rock over anorthosite waste rock is an effective way to reduce Ni levels in drainage waters from the Lac Tio mine materials.

Thermal-Hydrological-Chemical Modeling of a Covered Waste Rock Pile in a Permafrost Region

In order to reduce contaminant mass loadings, thermal cover systems may be incorporated in the design of waste rock piles located in regions of continuous permafrost. In this study, reactive transport modeling was used to improve the understanding of coupled thermo-hydrological and chemical processes controlling the evolution of a covered waste rock pile located in Northern Canada. Material properties from previous field and laboratory tests were incorporated into the model to constrain the simulations. Good agreement between simulated and observational temperature data indicates that the model is capable of capturing the coupled thermo-hydrological processes occurring within the pile. Simulations were also useful for forecasting the pile’s long-term evolution with an emphasis on water flow and heat transport mechanisms, but also including geochemical weathering processes and sulfate mass loadings as an indicator for the release of contaminated drainage. An uncertainty analysis was carried out to address different scenarios of the cover’s performance as a function of the applied infiltration rate, accounting for the impacts of evaporation, runoff, and snow ablation. The model results indicate that the cover performance is insensitive to the magnitude of recharge rates, except for limited changes of the flow regime in the shallow active layer. The model was expanded by performing an additional sensitivity analysis to assess the role of cover thicknesses. The simulated results reveal that a cover design with an appropriate thickness can effectively minimize mass loadings in drainage by maintaining the active layer completely within the cover.

Case Report: Soldier With Latrodectism After Black Widow Spider Bite During a Field Training Exercise.

Latrodectism from black widow spider (BWS) bites is rare in the United States. Latrodectism is a severe systemic manifestation of the envenomation that includes severe abdominal pain mimicking acute surgical abdomen and, in rare cases, could lead to acute myocarditis and rhabdomyolysis. The BWS typically inhabits dark, low-lying areas such as woodpiles, tree stumps, outdoor storage, outdoor furniture, outdoor toilets, and rock piles and is most active during warm weather months. Military service members often participate in field training exercises during warm weather in wooded areas littered with woodpiles and tree stumps; therefore, they are at an increased risk for bites by arachnids. We report the case of a 26-year-old active duty male soldier evacuated from field training with latrodectism and possible envenomation-induced myocarditis after a suspected BWS bite.

Investigating the Influence of Structure and Heterogeneity in Waste Rock Piles on Mass Loading Rates—A Reactive Transport Modeling Study

Placement methods and material availability during waste rock pile (WRP) construction may create significant heterogeneities in physical and geochemical parameters (such as grain size, permeability, mineralogy, and reactivity) and influence the internal pile structure. Due to the enormous scale of WRPs, it is difficult to capture the influence of heterogeneities on mine drainage composition and evolution. Although laboratory- or field-scale experimental studies have provided much insight, it is often challenging to translate these results to full scale WRPs. This study uses a numerical modeling approach to investigate the influence of physical and chemical heterogeneities, structure, and scale on the release of acid rock drainage (ARD) through 2D reactive transport simulations. Specifically, the sensitivity of drainage quality to parameters including grain size distribution, sulfide mineral weathering rates, abundance and distribution of primary minerals, and pile structure as a function of construction methods are investigated. The geochemical model includes sulfide oxidation, pH buffering by calcite dissolution, and ferrihydrite and gypsum as secondary phases. Simulation results indicate that the implications of heterogeneity and construction method are scale-dependent; when grain size distribution trends observed in a pile's core are applied to the entirety of a pile, results between push- and end-dumping methods vary substantially—however, predicted drainage for different construction methods become more similar when features such as traffic surfaces, structural variation, and multiple benches are also considered. For all scales and construction methods investigated, simulated results demonstrate that pile heterogeneity and structure decrease peak mass loading rates 2 to 3-fold, but cause prolonged ARD release compared to the homogeneous case. These findings have implications for the economics of planning water treatment facilities for life of mine and closure operations.

Shelter effect of the gaps within rock piles to reduce the predation on Japanese eel <i>Anguilla japonica</i>

ニホンウナギ資源減少の原因の1つとして，鳥類からの被食リスクを低減する隠れ場所となると考えられる浮き石の，河川改修による減少が挙げられる。本研究では，浮き石による間隙の存在が，本種の生残に影響を与えるかを検証するために，間隙が利用可能な池と利用不可能な池の2群における生残率と肥満度の変化量を比較する実験を行った。その結果，間隙が利用可能な池では供試魚の生残率が有意に高く，浮き石による間隙は捕食者である鳥類から餌として発見される可能性を下げる効果があることが確認された。

Evolution of Neoarchean–Paleoproterozoic basement in the Brunovistulia terrane, S Poland: geological, P-T and geochemical records

Brunovistulia is a composite terrane of Gondwana descent that eventually was accreted to the SW margin of Baltica, central Europe. It is built of metagneous and metasedimentary rocks that originated mainly between 650 and 550 Ma. However in the Upper Silesian part of Brunovistulia, much older fragments have been drilled, which yielded U-Pb zircon ages between 2.75 and 2.0 Ga. They have been interpreted as an “exotic” constituent of the Brunovistulia superterrane, named the Rzeszotary Terrane. Our geological and geochemical studies of the Rzeszotary borehole cores yielded new data on the composition, provenance and evolution of that terrane. Precursors of the Rzeszotary complex were separated from the depleted mantle prior to or around 3.2–3.0 Ga. At 2.75–2.6 Ga, a juvenile magmatic arc edifice formed, beneath which oceanic lithosphere was subducted. Decompression melting of the mantle brought about tholeiite magmas of IAT/MORB composition with LILE additions. Tonalitic and trondhjemitic precursors of gneisses present today were formed at that time, probably due to partial melting of mantle-derived wet basalts at the base of the island arc. Around 2.0 Ga, the arc collided with an unspecified cratonic mass and was subject to orogenic deformation, metamorphism and migmatization. The entire arc edifice was then strongly shortened and forced down to depths equivalent to ~6–12 kbar where the rocks underwent contractional deformation and metamorphism (~500–700°C). Tonalites and trondhjemites were changed to gneisses, and basites to epidote- and garnet amphibolites. These rocks underwent syntectonic migmatization through the mechanism of segregation/differentiation in the presence of fluids and incipient partial melting. Synmetamorphic shortening of the rock pile, which led to folding and heterogeneous development of shear zones with thrust kinematics, terminated with intrusions of K-granites at 2.0 Ga, being followed by some brittle-ductile deformation of unconstrained timing. The 2.0 Ga event may have been connected with the 2.1–1.8 Ga global amalgamation of the Paleoproterozoic supercontinent of Columbia. Later the future Rzeszotary terrane was detached from the Gondwana mainland, reassembled and eventually, in the Neoproterozoic, it became part of the foreland of the Cadomian Orogen in Central Europe.

A black‐box automated approach to calibrate numerical simulations and optimize cover design: Application to a flow control layer constructed on an experimental waste rock pile

AbstractMining operations often produce large volumes of waste rock to access economically valuable mineralized zones. Waste rock is usually stored in surface piles, the construction and reclamation of which represent a challenge for the industry. A flow control layer (FCL) made of crushed waste rock or sand and constructed on top of each waste rock bench could contribute to control water infiltration, thus improving waste rock pile stability and limiting contamination. An experimental waste rock pile was built and instrumented at the Tio mine (Rio Tinto Fer et Titane, Canada) to evaluate the performance of an FCL in field conditions. Large infiltration tests and rainfall monitoring were carried out, and measured outflow and water contents were used to calibrate numerical simulations. However, data were noisy and sometimes incomplete, and the models were difficult to calibrate. A new automated calibration approach was therefore proposed. An algorithm was developed to automate the numerical simulation calibration, using a black‐box method that involves solving an optimization problem on a function without an analytic form. The approach was applied on measurements obtained from large‐scale infiltration tests and validated using 2 yr of field monitoring data. Finally, the automated approach was adapted to optimize the design of the FCL, and an optimal design (material properties and layer thickness) was recommended based on local climate conditions. The proposed automated method could contribute to reduce the bias induced by manual calibration and allows for rapid multivariable calibration and optimization for a broad spectrum of mine waste cover system applications.

Modeling of Thermal-Hydrological-Chemical (THC) Processes During Waste Rock Weathering Under Permafrost Conditions

The oxidation of sulfide minerals such as pyrite present in waste rock results in elevated sulfate, enhanced metal loadings and in many cases low pH conditions. Recently, many mines have opened in remote areas, including regions subject to permafrost conditions. In these regions, freeze-thaw cycles and the possible development of permafrost in mine waste add to the complexity of weathering processes, drainage volumes and mass loadings. To assess weathering in these waste rock piles, the reactive transport code MIN3P-HPC has been enhanced by implementing constitutive relationships related to freeze-thaw cycles that control flow patterns, solute transport, generation and transport of heat, as well as geochemical reactions and their rates. Simulations of a hypothetical pyrite-rich waste rock pile placed onto natural permafrost were conducted under reference climate conditions. Additionally, the effect of a warming climate was also studied through a sensitivity analysis. The simulation results indicate a potentially strong coupled effect of sulfide mineral weathering rates and a warming climate on the evolution and persistence of permafrost within waste rock piles and the release of acidic drainage. For relatively low sulfide mineral oxidation rates, the simulations indicate that permafrost can develop within waste rock piles, even under warming climate conditions. However, the results for low reactivity also show that mass loadings can increase by >50% in response to a slight warming of climate (3°C), relative to reference climate conditions. For the chosen reference reaction rates, permafrost develops under reference climate conditions in the simulated waste rock pile; however, permafrost cannot be maintained for a marginally warmer climate, leading to internal heating of the pile and substantially increased production of acidic drainage (>550%). For high reaction rates, the simulations suggest that internal heating takes place irrespective of climate conditions. Evaluation of thermal covers indicates that significant reductions of mass loadings can be achieved for piles with low and reference reactivity (91–99% in comparison to uncovered piles), but also suggest that thermal covers can be ineffective for piles with high sulfide content and reactivity. Together, these simulations provide insights into the complex interactions controlling waste rock weathering in cold-region climates.

Mapping Potentially Acid Generating Material on Abandoned Mine Lands Using Remotely Piloted Aerial Systems

Weathering and transport of potentially acid generating material (PAGM) at abandoned mines can degrade downstream environments and contaminate water resources. Monitoring the thousands of abandoned mine lands (AMLs) for exposed PAGM using field surveys is time intensive. Here, we explore the use of Remotely Piloted Aerial Systems (RPASs) as a complementary remote sensing platform to map the spatial and temporal changes of PAGM across a mine waste rock pile on an AML. We focus on testing the ability of established supervised and unsupervised classification algorithms to map PAGM on imagery with very high spatial resolution, but low spectral sampling. At the Perry Canyon, NV, USA AML, we carried out six flights over a 29-month period, using a RPAS equipped with a 5-band multispectral sensor measuring in the visible to near infrared (400–1000 nm). We built six different 3 cm resolution orthorectified reflectance maps, and our tests using supervised and unsupervised classifications revealed benefits to each approach. Supervised classification schemes allowed accurate mapping of classes that lacked published spectral libraries, such as acid mine drainage (AMD) and efflorescent mineral salts (EMS). The unsupervised method produced similar maps of PAGM, as compared to supervised schemes, but with little user input. Our classified multi-temporal maps, validated with multiple field and lab-based methods, revealed persistent and slowly growing ‘hotspots’ of jarosite on the mine waste rock pile, whereas EMS exhibit more rapid fluctuations in extent. The mapping methods we detail for a RPAS carrying a broadband multispectral sensor can be applied extensively to AMLs. Our methods show promise to increase the spatial and temporal coverage of accurate maps critical for environmental monitoring and reclamation efforts over AMLs.

Hydrologic and Environmental Behavior of GeoWaste and Waste Rock in Field Experimental Piles

The focus of this study was on the evaluation of hydrologic and environmental behavior observed in GeoWaste and waste rock test piles. GeoWaste is a mixture of fast-filtered tailings and waste rock prepared as a tailings-dominated mixture. The two test piles included potentially acid-generating (PAG) waste rock and were operated for 26 months to evaluate whether GeoWaste can suppresses sulfide oxidation and production of metal-rich acid mine drainage relative to PAG waste rock. The test piles were constructed in the shape of truncated 5-m-tall pyramids with 25-m base sides and flat 5-m × 5-m top surfaces. Water content, temperature, electrical conductivity, and oxygen concentration were monitored in four layers and at five locations within each layer in both test piles. In addition, 5-m × 5-m lysimeters were installed at the base of each pile to collect leachate. Approximately 2660 mm of water was added to the surfaces of the test piles via precipitation and irrigation (irrigation ≈ 1050 mm applied at an approximately constant rate for 70 days). The measured saturation, oxygen concentration, electrical conductivity, and temperature in the GeoWaste and waste rock piles suggest more sulfide oxidation occurred in the waste rock pile compared to the GeoWaste pile. Observations from the pile experiments suggest that co-managing mine waste in the form of GeoWaste reduced acid generation compared to waste rock alone due to the lower permeability and unsaturated state of the GeoWaste pile that reduced downward migration of moisture and inhibited drainage.

Geophysical modeling of the crustal boundary between the Central and Oaxaquia terranes in northern Mexico

On the boundaries of the states of Coahuila and Zacatecas in northern Mexico, scarce outcrops of a Triassic subduction complex have been used to infer in several positions a tectonostratigraphic terranes boundary. This crustal boundary is covered by a pile of Jurassic volcanosedimentary rocks and a thick, folded, and thrusted Mesozoic sedimentary marine succession. We carried out detailed mapping, geological cross-sections, and a geophysical survey using magnetic and gravity data to model the buried boundary between these crustal blocks. Qualitative analysis of the magnetic and gravity anomalies was performed in order to determine the crustal boundary. It was integrated with in situ rock magnetic susceptibility and density data obtained in the laboratory to restrict the inversion process. The calculated models helped us to better constrain a regional structural lineament, named Las Norias fault. This fault divides two cortical blocks, the Central terrane and Oaxaquia microcontinent, whose physical properties and styles of deformation in the Mesozoic cover are very contrasting.

Positional behavior, habitat use, and forelimb morphology of Père David’s Rock Squirrels Sciurotamias davidianus (Milne-Edwards, 1867) (Sciuridae, Rodentia) in the Qinling Mountains, Shaanxi, China

Rock piles, boulder stacks, and vertical cliffs with ledges represent terrestrial habitats with a complex and irregular network of variably positioned available substrates demanding special morphological and behavioral adaptations. In this context, the current study integrated forelimb functional morphometrics with data on the positional behavior of wild Chinese rock squirrels (Sciurotamias davidianus) in the Qinling Mountains, China. Similar information is important for understanding the adaptation of squirrels in specific habitats and is fundamental for elucidating shifts between arboreality and terrestriality within this group. This endemic Chinese squirrel used extensively rocky and cliffy habitats, with rocks as the primary substrate used. Quadrupedalism, claw climb, stand, and claw cling were the dominant modes. These findings indicate that its ecology is best described as petrous or saxicolous. In terms of forelimb morphology, Chinese rock squirrels displayed scansorial adaptations, associated with increased climbing activities. Considering the phylogenetic position of S. davidianus, our findings on the locomotor ecology and the morphological adaptations of the forelimb suggest that early marmotins were also scansorial. Moreover, Chinese rock squirrels likely retained the ancestral marmotin morphotype, in relation to the challenging habitats they exploit. Climbing and clinging adaptations are necessary to overcome the irregularities of rocky habitats and occasional use of trees, seeking shelter, and increasing access to differential resources. Similar research on other rock-dwelling mammals will help elucidate morphological and behavioral adaptations for exploiting this particular habitat.

The correlation between drainage chemistry and weather for full-scale waste rock piles based on artificial neural network

In this paper, a machine learning algorithm based on artificial neural network architecture investigates the correlation between drainage chemistries in seepage water and ambient weather conditions around waste rock piles. The proposed neural network consists of a long short-term memory unit and a fully connected neural network which uses sequenced input to consider current and previous weather impact on the drainage chemistries. A 20-year (1998–2017) monitoring database obtained from the full-scale waste rock pile of the Equity Silver mine in BC, Canada is used for validating the proposed approach. The neural network is trained based on total precipitation and mean temperature as input and the acidity as output. The results indicate that the calculated acidity from the trained neural network matches with that measured in the field well. In addition, the accuracy of calculated acidity can be further increased by adding a time tag of acidity measurement date into the input layer. This refined approach can capture the long-term evolution and dynamics of hydrogeochemical and biochemical properties inside the waste rock piles.

In situ monitoring of an inclined cover made with mine waste materials to control water infiltration on a reactive waste rock dyke

The development of a cover for inclined acid-generating areas, such as the external face of dykes and the slope of waste rock piles, is undoubtedly one of the biggest technical reclamation challenges at several mine sites. The LaRonde mine site, owned and operated by Agnico Eagle Mines (Quebec, Canada) is currently engaged to identify an optimal reclamation scenario for the Dyke 1 of its acid-generating tailings storage facilities. One of the promising reclamation options for controlling water infiltration in the acid-generating waste rock on the Dyke 1 is the use of an inclined cover built with available mine waste materials. An instrumented inclined cell with an inclination angle of 18.3 degrees was built on a slope of this dyke to validate if low sulfide tailings and non potentially acid-generating waste rock can be used as cover material to reclaim the Dyke 1. The instrumented inclined cell was monitored for 3 years (2017 to 2019) using volumetric lysimeters, suction sensors, and volumetric water content sensors. The monitoring was done under natural climatic conditions and artificial wetting events. Under natural conditions, less than 1% (5 mm) of incident rainfall percolated in the volumetric lysimeters installed along the slope of the inclined cell. Under controlled conditions associated with artificial wetting events of 6.4 mm/h over a period of 12 h, net percolation values between 1 and 9% (4 to 60 mm) of the sum of incident precipitation were measured. The distance between the top of the cell and the Down Dip Limit (DDL) point was greater than the slope length of the cover under natural conditions and the DDL point moved from the bottom toward the top to reach values between 12 and 20 m from the top of the slope when the wetting events were applied on the cover. These results confirmed the suitability of mining materials as an inclined cover material to control water infiltration in reactive mine waste rocks.

Fiber Optic Measurements of Soil Moisture in a Waste Rock Pile.

The design and construction of a waste rock pile influences water infiltration and may promote the production of contaminated mine drainage. The objective of this project is to evaluate the use of an active fiber optic distributed temperature sensing (aFO-DTS) protocol to measure infiltration and soil moisture within a flow control layer capping an experimental waste rock pile. Five hundred meters of fiber optic cable were installed in a waste rock pile that is 70 m long, 10m wide, and was covered with 0.60 m of fine compacted sand and 0.25 m of non-reactive crushed waste rock. Volumetric water content was assessed by heating the fiber optic cable with 15-min heat pulses at 15 W/m every 30 min. To test the aFO-DTS system 14 mm of recharge was applied to the top surface of the waste rock pile over 4h, simulating a major rain event. The average volumetric water content in the FCL increased from 0.10 to 0.24 over the duration of the test. The volumetric water content measured with aFO-DTS in the FCL and waste rock was within ±0.06 and ±0.03, respectively, compared with values measured using 96 dielectric soil moisture probes over the same time period. Additional results illustrate how water can be confined within the FCL and monitored through an aFO-DTS protocol serving as a practical means to measure soil moisture at an industrial capacity.

Modelling three‐dimensional space to design prey refuges using video game software

AbstractRefuges can be ecologically important, allowing access only to some species or individuals and providing prey protection from predators. Creation of refuges can be used to protect threatened species from introduced predators, which can have large negative impacts that are difficult to attenuate via other means. To design refuges for conservation purposes, refuge accessibility to different species must be understood. Traditional techniques are not adequate to measure or describe complex three‐dimensional spaces which are often important refuges. We designed a novel predictive method for modeling three‐dimensional refuge space using video game software that simulates real‐world physics (Unity, PhysX). We use the study system of endemic New Zealand skinks (Oligosoma spp.), their introduced predators, house mice (Mus musculus), and the habitat of interstitial spaces within rock piles to demonstrate how this modeling technique can be used to inform design of habitat enhancement for conservation. We used video game software to model realistic rock piles and measure their interstitial spaces, and found that the spaces we predicted matched those we measured in real rock piles using computed tomography (CT) scanning. We used information about the sizes of gaps accessible to skinks and mice and the results of our modeling to determine the optimal size of rocks to create refuges which would protect skinks from mice. We determined the ideal rock size to be those with graded diameters of 20–40 mm. The approach we developed could be used to describe interstitial spaces in habitats as they naturally occur, or it could be applied to design habitats to benefit particular species.

The spatial distribution of soil heavy metals and ecological restoration of Datong Abandoned Coal Mine in Huainan City

Based on laboratory analysis of soil samples collected from abandoned coal mine in Datong area, content of heavy metals in the soils was monitored and the soils were evaluated for heavy metal pollution. The spatial distribution of heavy metals was study with means of Kriging method by under ArcGIS environment in the abandoned coal mine in Huainan area. The results show: (1) the content of 5 types of heavy metals( Hg, Cd, Cr, Pb, Cu) were all higher than Huainan area background value of soil elements, among of these heavy metals, the enrichment of Cd was higher and polluted quite seriously; the enrichment of Hg, Cr, Pb and Cu was lower, and polluted lightly comparatively. (2) The coal mine waste rock pile and abandoned chemical plant were the main pollution sources. (3) The heavy metal concentrations and space distribution were mainly affected coal mine waste rock pile, and abandoned chemical plant. (4) Positive correlation between concentrations of most heavy metals was significant, and there is a certain relationship between concentrations of heavy metals and organic matter, nitrogen, available phosphorus. On the basis of the above research, some countermeasures were put forward for ecological restoration in Datong abandoned coal mine.