Large Rock Research Articles

Design of an Ultrasound Sensing System for Estimation of the Porosity of Agricultural Soils.

The design of a readily useable technology for routine paddock-scale soil porosity estimation is described. The method is non-contact (proximal) and typically from "on-the-go" sensors mounted on a small farm vehicle around 1 m above the soil surface. This ultrasonic sensing method is unique in providing estimates of porosity by a non-invasive, cost-effective, and relatively simple method. Challenges arise from the need to have a compact low-power rigid structure and to allow for pasture cover and surface roughness. The high-frequency regime for acoustic reflections from a porous material is a function of the porosity ϕ, the tortuosity α∞, and the angle of incidence θ. There is no dependence on frequency, so measurements must be conducted at two or more angles of incidence θ to obtain two or more equations in the unknown soil properties ϕ and α∞. Sensing and correcting for scattering of ultrasound from a rough soil surface requires measurements at three or more angles of incidence. A system requiring a single transmitter/receiver pair to be moved from one angle to another is not viable for rapid sampling. Therefore, the design includes at least three transmitter/reflector pairs placed at identical distances from the ground so that they would respond identically to power reflected from a perfectly reflecting surface. A single 25 kHz frequency is a compromise which allows for the frequency-dependent signal loss from a natural rough agricultural soil surface. Multiple-transmitter and multiple-microphone arrays are described which give a good signal-to-noise ratio while maintaining a compact system design. The resulting arrays have a diameter of 100 mm. Pulsed ultrasound is used so that the reflected sound can be separated from sound travelling directly through the air horizontally from transmitter to receiver. The average porosity estimated for soil samples in the laboratory and in the field is found to be within around 0.04 of the porosity measured independently. This level of variation is consistent with uncertainties in setting the angle of incidence, although assumptions made in modelling the interaction of ultrasound with the rough surface no doubt also contribute. Although the method is applicable to all soil types, the current design has only been tested on dry, vegetation-free soils for which the sampled area does not contain large animal footprints or rocks.

The first investigation of an Iron Age shell midden in Oman: The Nafūn complex

The Nafūn shell midden complex is a cluster of eight shell mounds in al-Wusṭā Governorate (south-central Oman). Located 40 km north of Duqm, the shell midden is part of a unique cultural landscape encompassing a variety of archaeological features. With a total of 207 recorded archaeological sites, the Nafūn area emerges as a significant site for studying the Early and Late Iron Age communities in south-central Oman. The first investigations of the shell midden were conducted between 2019 and 2022. Radiocarbon dating of charcoal samples from the site provided a date range of 1012–536 BCE (cal. 2σ), aligning with the Iron Age II (1000–600 BCE) material culture. Together with stratigraphic observations, this indicates that the midden was intermittently occupied for at least 500 years. Additional evidence indicates that there was also activity in the area during the Late Iron Age, evidenced by the presence of a large rock art site, circular stone burial mounds and numerous clusters of trilith stone monuments along the wadi Nafūn route, with a source of drinking water 3 km from the coast. Such findings underscore the importance of Nafūn as a significant site for enduring socio-economic and cultural contacts, strategically located at the mouth of the wadi that connects with the Indian Ocean. The effective utilisation of marine resources by the local communities not only supported their economic and subsistence needs but also fostered strong economic, social and cultural connections with the inland regions. Furthermore, it facilitated their active engagement in long-distance trade and interactions along the coastal areas. The unique combination of sites and the fusion of elements from both northern Oman and Dhofar make Nafūn an intriguing and, so far, undocumented intersection along the long-distance routes connecting the northern and southern cultural circles.

Development of the rolling extrusion rock bolt with constant resistance and large deformation

With the increasing excavation depth of underground engineering, engineering problems such as large deformation and rock burst caused by high geo-stress brings new challenges to the excavation and reinforcement of surrounding rock in deep underground engineering. The traditional rock bolt is prone to brittle fracture under high geo-stress due to its low elongation. Therefore, this work aims to develop a novel energy-absorbing bolt with constant resistance and large displacement to reinforce the surrounding rock with a risk of large deformation or rockburst. The novel energy-absorbing bolt refereed as rolling extrusion rock bolt (RE bolt) is mainly consists of sleeve tube with a variable cross-section, energy absorption slider with steel balls embedded, steel bar connected with the energy absorption slider. The rolling extrusion is adopted to produce the resistance force of the RE bolt, which avoids the sudden attenuation of resistance force and the abrasion of the energy absorption slider. The static pull test is conducted to study the resistance force and deformation characteristics of the RE bolt with different specifications. Results imply that the RE bolt has higher resistance force, larger deformation capacity and energy absorption capacity. The work of this study provides an effective solution for the reinforcement of surrounding rock in deep rock engineering.

Discrete element simulation of vibration compaction of slag subgrade

In this study, to improve the compaction quality and parameters of slag, discrete element models of irregular rock particles (10–60 mm) and circular soil particles (5 mm) were established based on on-site slag screening results. The motion of the vibratory roller was captured by coupling the roadbed model with the roller model in a simulation in which the roller vibrated and compacted the slag subgrade. The results indicated that (1) the best compaction was achieved when the small particle content was 40%, the medium particle content was 20%, and the large particle content was 40%. (2) When the slag was dominated by small rock particles, the optimum compaction frequency was 28 Hz, and when large rock particles dominated, the optimum compaction frequency was 33 Hz. (3) Rock particles were the primary particles that experienced stress in the vibration compaction, and the compressive force and displacement depended on the particle size. (4) The longitudinal and vertical displacements and rotation angles of the soil and rock particles were examined. The results of this study are conducive for advancing the understanding of slag compaction and improving the working efficiency and compaction quality of rollers.

ANALYSIS OF LIMESTONE QUARRY SLOPE STABILITY, NIMBOKRANG DISTRICT, JAYAPURA REGENCY, PAPUA, INDONESIA

Slope stability analysis generally uses the concept of factor of safety (FoS) value using several whole rock parameters. The slope stability analysis method that will be used in this research is the slope stability analysis method in open pit mines based on rock mass classification with the Rock Mass Rating (RMR) system and the Geological Strength Index (GSI) system and analyses the potential for landslides that can occur on slopes at that location with kinematics and limit equilibrium methods so that the type of landslide can be determined based on the intensity of the geological structure on the slope of the CV. Inti Jaya open pit limestone mine, in Wahab Village, Nimbokrang District, Jayapura Regency. This research aims to provide information on the current condition of the slope whether it is by safety standards, make slope engineering improvements and redesign safe slopes if unstable slope conditions are found. Research on the stability of limestone slopes begins with the collection of field data and rock samples. Furthermore, sample testing was carried out to obtain physical and mechanical properties and weighting of rock masses, which were then analysed to obtain the characteristics and quality of rock masses that would be applied using the finite element method with Slide 6 from Rocscience to determine the Factor of Safety (FK) and the design of safe slope geometry. The RMR value for slope 1 is 62, slope 2 is 61, and slope 3 is 62. So it can be concluded that the rock is included in rock mass class 2 with good quality. Based on the analysis of potential avalanche types, the three slopes have non-arc avalanche types. From the analysis carried out using Rocscience Slide 6.0 software, the FoS value for slopes in original, dry, and saturated conditions is obtained, where on slope 1: FoS in original conditions is 0.935, FoS in dry conditions is 1.619, and FoS in saturated conditions is 0.671. Then slope 2: FoS in original condition is 0.896, FoS in dry condition is 1.457, and FoS in saturated condition is 0.806. Slope 3: FoS in original condition is 3.490, FoS in dry condition is 4.199, and FoS in saturated condition is 3.368. So it can be concluded that slopes 1 and 2 are unsafe or unstable in original and saturated conditions so that landslides can occur. In the analysis of the FoS value of the actual condition of the slopes in the field using the Hoek & Brown method, the FoS value of slope 1 is 0.387, the FoS value of slope 2 is 0.579, and the FoS value of slope 3 is 1.272, it can be seen that the actual condition of the slopes in the field is slopes 1 and 2 in an unsafe or unstable state. Improvements must be made to the slope geometry to maintain the stability of the slope to remain safe or stable. The recommended improvement is to create a new working level for slopes 1 and 2, with steep height and large rock porphyry.

Development of non-hydrophilic similar materials for weakly cemented rocks and its experimental application in water conservation mining

Abstract The mining of coal mines in western China needs to focus on protecting groundwater. A non-hydrophilic similar material for simulating the development and hydraulic conductivity of weakly cemented overlying strata fractures was developed. Fine sand, coarse sand, and gypsum are used as aggregates. Paraffin and Vaseline are used as binders. The non-hydrophilic material ratios of weakly cemented sandy mudstone and medium-grained sandstone were determined by orthogonal experiments, and used for similar simulation tests. The results show that the non-hydrophilicity of rock-like materials can be adjusted to prevent them from softening and collapsing under the action of water. Non-hydrophilic materials of higher strength and brittleness of rocks can be achieved by adjusting the content of paraffin, fine sand, and gypsum. The non-hydrophilic materials of soft and large particle rocks can be achieved by adjusting the content of paraffin, fine sand, and gypsum. After the coal seam in a similar simulation experiment was extracted, the large area of weakly cemented rock above it underwent overall settlement and fracture. Although this part was located within the failure zone, there was no macroscopic water-conducting cracks generated. The height of the water-conducting fracture zone was lower than the height of the fracture zone classified by the traditional ‘three zone’ theory, which is consistent with the on-site measurements. This indicates that the prepared non-hydrophilic material is reliable. The similarity simulation method based on non-hydrophilic materials can enrich the means for studying the fracture and permeability of weakly cemented overlying rocks in coal mines.

Material balance evaluation method for water-bearing gas reservoirs considering the influence of relative permeability

In this paper, we developed a material balance method based on a two-phase flow equation for evaluating the development efficiency in gas reservoirs. The calculating results show that the theoretical curves of development performance simulated by material balance fit well with early production data and can be used to evaluate the development efficiency of the field. The influence parameters of the theoretical curves were analyzed by simulating a constant production gas reservoir. The results show that the numerical differences between the initial water saturation and the water saturation at the isotonic point of the relative permeability curve greatly influence the theoretical curves. The higher the ratio of water phase relative permeability to gas phase relative permeability, the higher the water-gas ratio in the early and middle periods of well production. It is beneficial to exploit the underground fluid with a large average rock compressibility coefficient which means a strong formation elastic energy. Besides, the value of initial water saturation will also influence the loss of formation elastic energy. This study extends the applicability of material balance and avoids the cost risk of field well testing. Therefore, it has a good practical significance.

Application research on composite support technology of concrete-filled steel tube support in high stress and large deformation soft rock roadway: A case study

Aiming at the surrounding rock control problem of high stress and large deformation soft rock roadway. This article takes the 141712 coal haulage uphill as the engineering background in Guizhou Panjiang Mining Area. Through field investigation, theoretical calculation, numerical simulation, and industrial tests, the deformation characteristics of surrounding rock and the mechanism of roadway instability and failure were revealed. And a composite support scheme of "bolt (cable) + grouting + concrete-filled steel tube support" was designed. A strengthening support mechanical model of “Three-arch” based on the concrete-filled steel tube support technology was established. The ultimate bearing capacity of the design scheme above is calculated, which meets the support load and can maintain the stability of the soft rock roadway. Through numerical simulation analysis, the distribution characteristics of the plastic zone, stress field and displacement field of the design scheme are obtained, and the rationality of the scheme is verified. The industrial tests were successfully applied and the field monitoring results show that the deformation is within the controllable range, effectively controls the deformation of the 141712 roadway. The research results can provide a reference case for the control of soft rock roadway with high stress and large deformation under similar complex conditions.

Large rock and ice avalanches frequently produce cascading processes in High Mountain Asia

Rock and ice avalanches – or combinations thereof – are among the most far-reaching types of hazards in the mountain cryosphere. Here, we report a first complete inventory of rock and ice avalanches in High Mountain Asia (HMA) and assess 60 events predominating from steep glacial and periglacial zones, including 29 cascading processes, resulting in 1366 casualties and >500,000 people displaced. Overall, these hazards are clearly not rare in HMA and are both lethal and destructive.

Life in a fishbowl: Space and environmental enrichment affect behaviour of Betta splendens.

The public has expressed growing concern for the well-being of fishes, including popular pet species such as the Siamese fighting fish (Betta splendens). In captivity, male Bettas behave aggressively, often causing injuries and death if housed together. As a result, they are typically isolated in small fishbowls, which has been widely criticised as cruel. To investigate the impact of keeping Bettas in these conditions, we recorded the behaviour of individual males in containers of different sizes that were either bare or enriched with gravel, large rocks, and live plants. When male Bettas were housed individually in small bowls (0.5 L) they spent less time swimming than they did when they were kept in larger aquaria (10, 38, and 208 L). Fish that were kept in enriched containers exhibited more instances of swimming. To determine if two male Bettas housed together might coexist peacefully if given enough space and cover from plants and large rocks, we quantified the behaviour of pairs of male Bettas in bare or enriched aquaria of different sizes (10, 38, 208, 378 L). Fish performed fewer approaches and aggressive displays, but not attacks, and more bouts of foraging, when in larger aquaria. This study shows that the small fishbowls typically used in pet stores suppress swimming behaviour in male Bettas and at least a 10-L aquarium is required to ensure full expression of swimming behaviour. Furthermore, even the use of very large aquaria cannot guarantee peaceful cohabitation between two males.

A Comprehensive Review on Sediment Transport, Flow Dynamics, and Hazards in Steep Channels

The hydrological channel networks of the steep mountains are extensively designated and organized geographic systems and are very complicated. They are composed of granular beds that are uneven and are subjected to fluid forces that fluctuate spatially and temporally. The flow and movement of sediment in these streams are significantly shaped by large rocks such as boulders. However, it is difficult to comprehend these mountain streams because significant information is unavailable regarding these channels as compared to plane bed streams. To address this issue, a critical review of the numerical, computational fluid dynamics, and machine learning mechanisms underlying sediment transport across different flow conditions in steep channels is presented while considering the current and foreseeable conditions for various sediment transport phenomena. The present study emphasized to carry out further analysis on these steep channels using advanced available techniques to get an insight into the morphology of these channels. Furthermore, the hazards associated with steep mountain channels are reviewed as they have a significant impact on infrastructure and habitation in mountainous regions.

Collective action problems led to the cultural transformation of Sāmoa 800 years ago.

In this research we identify the processes leading to hierarchical society in a region of Sāmoa, the often-labelled 'birthplace' of the Polynesian chiefdoms. Our analyses in the Falefa Valley on 'Upolu island combine lidar mapping and ground survey to reveal an extensive system of archaeological features: rock walls, ditches, and platforms. Excavation and radiocarbon dating underpin a feature chronology and characterize feature variation. Soil nutrient analyses and geoarchaeological coring indicate spatial differences in the agricultural potentional of the valley and human modification of the environment over time. Our results demonstrate that the construction of large rock walls, some several hundred meters long, began approximately 900-600 years ago, shortly after rapid population rise in Sāmoa. This was followed by the building of small rock walls, often enclosing rectilinear fields or platforms. Both rock wall types are concentrated in the western and northern regions of the valley and greater rock wall densities are associated with areas of higher agricultural potential. The earliest wall construction was penecontemporaneous with partial forest removal that created a more productive wetland environment in the southeastern region of the valley, an area later a focus of agricultural ditching. We propose that with population rise the variable fertility of agricultural land became a significant resource gradient, influencing the population in two ways. First, areas of more fertile agricultural land promoted territorial behaviour, including large rock walls, and led to a collective action problem. Second, niche construction in the form of human-induced environmental change created a productive wetland agricultural system that was enhanced with a reticulate ditch network, the maintenance of which also led to a collective action problem. We conclude that in the Falefa Valley, the second largest catchment in Sāmoa, collective action problems were the cause of increased social hierarchy and may underlie the origins of chiefdoms throughout Polynesia.

Detailed Bathymetry and Seafloor Backscatter Image Dataset for Monitoring Ecosystem Environment: Southern Ulleungdo

We obtained a detailed bathymetry dataset using multi-beam echo sounder around Neunggeol located at Southern part in Ulleungdo. The survey period was from September 1, 2019 and the bathymetry survey was carried out by RV Jangmok No2 of Korea Institute of Ocean Science and Technology. The instrument equipment used for the survey were Kongsbergs’s EM2040 (multi-beam echo sounder). The detailed bathymetry of the study area shows gradually depth change from about 4 to 190 m. The study area has relatively gentle slopes from the coast to 25 m and below about 125 m in depth, but a steep slope from about 25 to 125 m. The rocky bottom zones identified from detailed bathymetry and backscattered seafloor images are distributed in the northeastern sea of the coastal area, the central sea, and around Neunggeol. In particular, Neunggeol and the near large outcropping rock are tumulus-like submarine landforms, forming big vertical walls. The submarine cable buried between Ulleungdo and the Korean mainland appears in the northern seafloor of the survey area. Stopper stones and gravels sediment are distributed around it. The rocky bottom zone has a strong and irregular reflection intensity in the seafloor backscattered image and the sandy sediment zone has a relatively weak reflection intensity and a uniform pattern, so the two zones are well divided. We classified the sediment zones into fine-grained sediments, sandy sediments, and gravel-like sediments by using the different reflection intensities due to differences in sediment particle size in the seafloor image. Detailed bathymetry and seafloor backscattered image dataset around Neunggeol can be used as a basic data for habitat environment mapping.

Exploring the potential of smartphone photogrammetry for field measurement of joint roughness

Rock joints play a crucial role in determining the behavior and stability of rock masses. Despite their importance, there is a lack of devices for easily and accurately measuring joint roughness in field conditions. This research explores the potential of smartphone photogrammetry as a solution for large-scale joint roughness mapping. A large natural rock joint from an open pit mine in Yunnan, China, served as the specimen. Both two dimensional (2D) and three dimensional (3D) roughness parameters were utilized to characterize joint roughness. The study found that the accuracy of smartphone photogrammetry is acceptable when operated with guidance. The measurement errors were 1.7%, 4.7%, 7.8%, and 6.1% for the Z1, Ai, Z2, and PSD-D roughness parameters, respectively. In conclusion, this study demonstrates that using smartphone photogrammetry as a portable and cost-effective method for measuring joint roughness in field conditions has the potential to significantly benefit engineering geological investigations.

European plaice movements show evidence of high residency, site fidelity, and feeding around hard substrates within an offshore wind farm

Abstract Offshore wind farms (OWFs) are expanding rapidly in the North Sea, often creating spatial conflicts with fisheries. Managing such conflicts requires knowledge on the impact of OWFs on the spatial distribution and movement behaviour of fished species. However, such knowledge is still lacking, especially for soft sediment fish such as flatfish, which are vital fisheries resources in the region. Therefore, we used acoustic telemetry to examine the spatial behaviour of European plaice in relation to an OWF and its structures. In a small study area (1.37 km2), we observed high residency for plaice around the turbines and scour protection layer (SPL), which consists of large rocks around the turbine foundation. The fish primarily resided on sandy sediments near the hard substrates, but showed a diurnal pattern of proximity to the turbine, being closer during the day. Considering their trophic ecology, these findings suggest that plaice moves towards the SPL for feeding opportunities on the hard substrate, potentially leading to increased ecological fish production within OWFs. Although most plaice moved away from the OWF in winter, likely towards spawning grounds, many exhibited high site fidelity returning to the study area after the winter migration. OWFs thus offer protection from fishing mortality as “closed” feeding grounds in spring and summer, but not during winter spawning migrations, which may result in spillover effects. These insights should inform local fisheries management in relation to plaice movement within and around OWFs.

A further new species of Palaemonella Dana, 1852 from the coasts of the Arabian Peninsula (Malacostraca: Decapoda: Palaemonidae).

Palaemonella yalla sp. nov. is described based on two ovigerous females: the holotype from Thuwal, Red Sea coast of Saudi Arabia, and a non-type specimen from Masirah Island, eastern Oman. The new species is very close to P. okunoi Komai & Yamada, 2015, from which it is essentially distinguishable by the distoventrally armed merus of the second pereiopods. The Saudi Arabian specimen was extracted from a burrow of an unknown host, whereas the Omani specimen was found in a muddy depression created after flipping a large rock deeply embedded in the sediment.

Determination of in situ hydrocarbon contents in shale oil plays: Part 3: Quantification of light hydrocarbon evaporative loss in old cores based on preserved shales

Petroleum resource assessment obtained from laboratory tests on old core samples shelved in the open environment tend to underestimate in situ resources. Therefore, hydrocarbon loss and its restoration need to be investigated. The hydrocarbon loss was studied via the difference of programmed pyrolysis parameter (Rock–Eval derived S1) between preserved/fresh cores and their replicas that had been long-term exposed to ambient conditions. However, the in situ hydrocarbon potential is still seemed to be underestimated, because the effect of sample crushing and crucible waiting on pristine S1 detection did not receive enough attention. To solve this issue, 50 preserved shale core samples with Ro from 1.00% to 1.51% were collected from the K1qn1 Formation of northern Songliao Basin, Eastern China. All the samples were subjected to four parallel experiments: Dean–Stark extraction and nuclear magnetic resonance (NMR) T1–T2 mapping, using large rock pieces 3–5 cm in size, and thermal desorption gas chromatography (TD–GC) and Rock–Eval analysis, using 60-mesh powdered samples. In addition, a time series of TD–GC and Rock–Eval analyses were conducted on a preserved shale sample to investigate hydrocarbon loss during sample crushing, Rock–Eval crucible waiting process, and elapse-time exposure to the open environment. Rock–Eval pyrolysis was also conducted on one month-exposed shale cores and solvent-extracted samples. The results show that the total hydrocarbon content of large rock pieces is significantly greater than that of powdered samples. Sample crushing or grinding leads C8− light hydrocarbons to evaporate, and results in a loss of approximately 35% of S1. Rock–Eval crucible waiting process causes C14− hydrocarbons to evaporate, and results in an additional 25% loss of S1. To compensate for the sample crush induced S1 loss, an exponential distribution model was proposed based on the C8+ hydrocarbons in the TD–GC S1 fingerprints. Sample maturity, pristine light hydrocarbon (C14−) proportions, organic matter richness, and oil-bearing pore size primarily control the hydrocarbon loss of old shale samples. The higher the proportion of C14− and the lower the abundance of organic matter, the higher the amount of hydrocarbon loss. Finally, S1 restoration coefficient charts for large rock pieces and powdered samples with Ro ranging from 1.00% to 1.42% are provided. It highlights that previous studies have severely underestimated the in situ S1 when using the Rock–Eval method. This research has great implication for estimating in situ hydrocarbon potential using conventional coring samples.

Georeferencing of terrestrial radar images in geomonitoring using kernel correlation

ABSTRACT Terrestrial radar interferometry (TRI) provides accurate observations of displacements in the line-of-sight (LOS) direction and is therefore used in various monitoring applications. However, relating these displacements directly to the 3d world is challenging due to the particular imaging process. To address this, the radar results are projected onto a 3d model of the monitored area, requiring georeferencing of the 3d model and radar observation. However, georeferencing relies on manual alignment and resource-intensive on-site measurements. Challenges arise from the significant disparity in spatial resolution between radar images and 3d models, the absence of identifiable common natural features and the relationship between image and spatial coordinates depending on the topography and instrument pose. Herein, we propose a method for data-driven, automatic and precise georeferencing of TRI images without the need for manual interaction or in situ installations. Our approach (i) uses the radar amplitudes from the TRI images and the angle of incidence based on the 3d point cloud to identify matching features in the datasets, (ii) estimates the best-fitting transformation parameters using Kernel Density Correlation (KDC) and (iii) requires only rough initial approximations of the radar instrument’s pose. Additionally, we present the correct relation between cross-range and azimuth for ground-based radar instruments. We demonstrate the application on a geomonitoring case using TRI data and a point cloud of a large rock cliff. The results show that the positions of the radar image can be localized in the monitored 3d space with a precision of a few metres at distances of over 1 k m . This is an improvement of almost one order of magnitude compared to what had been achieved using standard approaches and direct observation of the radar instrument’s pose. The proposed method thus contributes to the automation of TRI data processing and improved localization of small-scale deformation areas detected in radar images.

Engineering geological characteristics and failure mechanics of Jure rock avalanche, Nepal

IntroductionThe rock avalanches are a frequent and disruptive phenomenon in the Himalayas and other mountain chains. To minimize future losses, it is essential to investigate the engineering geological causative factors and mechanism of these mass wasting events.Study areaThe present work is aimed at assessing the failure mechanism of the disastrous 2014 Jure rock avalanche along Araniko Highway, Northern Nepal. The event had blocked the Sunkoshi River and blocked an economically significant route to China.Geotechnical properties and analysisInitially, rockmass characterization and intact strength attribute were determined for the site to classify the failure zone. The parameters measured and obtained from the field and laboratory were integrated into the analytical models to obtain a conclusive interpretation of the failure mechanism. Structural, kinematic, and key block theory analyses have been carried out for decipher the evolution of the failure zone.Results and discussionRock mass was found to be of fair quality, however, the structural instabilities and the presence of water has led to a progressive failure. Movement of the key block and subsequent sliding of wedges and foot failure appears to be a possible failure mechanism.ConclusionThe present research explores the contributory engineering geological aspects of the Jure rock avalanche. The investigation results can be used to tackle similar large scale rock avalanches in similar geological terrains and thus minimizing the losses.

Early-Middle Acheulean Occupation of the Northern Transcaucasian Highland

In the northern part of the Transcaucasian Highland (Lori Depression, Armenia), three stratifi ed sites dating to the Early-Middle Acheulean—Karakhach, Kurtan I, and Muradovo—have long been subject to archaeological studies. On the basis of absolute dates and paleomagnetic records relating to the fi rst two sites, their age falls in the interval between the mid-Early and initial Middle Pleistocene. All three sites yielded a uniform industry with a peculiar toolset (various choppers, picks including chisel-ended ones, handaxes, large scrapers, macro-chisels, and macro-knives), manufactured mostly on natural tabular fragments of local volcanic rocks. Certain indicators of this industry, such as subrectangular and fan-shaped choppers, slab-like chisels, etc., are described. Information on 28 other localities with Acheulean artifacts, including 11 stratifi ed ones, recently discovered in various parts of the Lori Depression and in adjacent areas of the Shirak Depression and the Debed River valley, is provided. It is demonstrated that the lithics from all these sites belong to the Karakhach tradition. Data are cited suggesting that three sites (Yagdan, Agvi-canyon, and Agvorik) are over 2 mln years old, and two more (Kurtan II and Dzhradzor) are at least 1.5 mln years old. It is concluded that people associated with the Karakhach Acheulean tradition had appeared in the northern Transcaucasian Highland ~2.0 Ma BP, then settled widely in this area, and remained there for several hundred thousand years. In my view, this may be explained by the very favorable environmental conditions of the region during the Early Pleistocene, and by the abundance of large rock fragments suitable for tool manufacture.