Shock‐metamorphic microfeatures in chert from the Jebel Waqf as Suwwan impact structure,Jordan

Abstract– The petrographic investigation of a shocked, chalcedony‐, quartzine‐, and quartz‐bearing allochthonous chert nodule (probably Upper Cretaceous) recovered from surficial wadi gravels in the inner parts of the central uplift of the approximately 6 km in diameter Jebel Waqf as Suwwan impact structure, Jordan, reveals new potential shock indicators in microfibrous–spherulitic silica, in addition to well‐established shock‐metamorphic effects in coarser crystalline quartz. The microcrystalline chert groundmass exhibits a macroscopic dendritic and suborthogonal fracture pattern commonly associated with thin “recrystallization bands” that intersect the pre‐existing diagenetic chert fabric. Fibrous aggregates of quartzine spherulites in chalcedony‐quartzine‐quartz veinlets locally have a shattered appearance and show conspicuous “curved fractures” perpendicular to the quartzine fiber direction (and parallel to [0001]) that commonly trend subparallel to planar fractures (PFs) in neighboring shocked quartz. Quartz exhibits PFs, feather features (FFs), and mainly single sets of planar deformation features (PDFs) parallel to the basal plane (0001) (Brazil twins) and, rarely, additional PDFs parallel to {101¯3}. Shock petrography indicates shock pressures of ≥10 GPa and high shock‐induced differential stresses that affected the chert nodule. The internal crosscutting relationships of primary diagenetic and impact‐related deformational features together with shockpressure estimates suggest that the curved fractures across quartzine spherulites might represent specific (low‐ to medium‐pressure) shock‐metamorphic features, possibly in structural analogy to basal plane PFs in quartz. The dendritic–suborthogonal fractures in the microcrystalline chert groundmass and recrystallization bands are likely related to impact‐induced shear deformation and recrystallization, respectively, and cannot be considered as definite shock indicators.     

On the development of a seismic source zonation model for seismic hazard assessment in western Saudi Arabia

A new seismic source model has been developed for the western part of the Arabian Peninsula, which has experienced considerable earthquake activity in the historical past and in recent times. The data used for the model include an up-to-date seismic catalog, results of recent studies of Cenozoic faulting in the area, aeromagnetic anomaly and gravity maps, geological maps, and miscellaneous information on volcanic activity. The model includes 18 zones ranging along the Red Sea and the Arabian Peninsula from the Gulf of Aqaba and the Dead Sea in the north to the Gulf of Aden in the south. The seismic source model developed in this study may be considered as one of the basic branches in a logic tree approach for seismic hazard assessment in Saudi Arabia and adjacent territories.     

Aeromagnetic data over Harrat Lunayyir and surrounding areas,western Saudi Arabia

Harrat Lunayyir is one of the smaller lava fields in western Saudi Arabia that is of current interest due to a dike intrusion episode in 2009, an ongoing swarm of earthquakes and the possible hazard that pose. In addition to seismology, other geophysical data have been used to study the structure of the area, and the available aeromagnetic information is shown and discussed here. The reduced to the pole (RTP) magnetic grid and its enhancements have been used to define some of the main anomalies, and these have been correlated with the known geology, including the Red Sea coastal dike system. There are numerous linear features that are possibly related to the dikes or faulting, but within the area of the harrat, details due to the underlying structure are largely obscured by the magnetic surface lavas. Northeasterly trends in the magnetic data may indicate old zones of weakness that intersect one of the main coastal dikes at the location of the recent seismic activity and surface fissure, suggesting that this is a point of weakness resulting in the volcanism and seismicity that also appears to be largely limited to two of the NE trends. The association of the recent seismicity with a known geological and aeromagnetic feature is important in determining the seismic hazard for the region, especially if the location of future activity can be used to reduce overall uncertainty in the analysis by identifying potential fault sources. Here, the seismicity appears to lie on one of the NNW-trending coastal dikes that have been reactivated recently along a section between two NE-trending older faults.     

Assessment and Control of Ore Dilution in Long Hole Mining: Case Studies

Unplanned ore dilution has a direct and large influence on the cost of a stope, and ultimately on the profitability of a mining operation. This paper presents the results of an examination of factors influencing ore dilution in a blasthole stoping environment. For the study, a comprehensive database was established, incorporating information related to the design, construction, excavation and cavity surveys of 172 sequentially mined long hole stope case histories from two orezones. Through a review of the case studies, it was demonstrated that, in addition to stope dimension, the amount of unplanned dilution differed according to stope type. Five stope types were identified, based on their position within a tabular blasthole mining sequence. Measured overbreak varies with stope type, with secondary stopes generating a greater volume of hanging-wall dilution than do primary stopes. Furthermore, a case study is presented to demonstrate the role cablebolts installed in the stope hanging-wall play to control ore dilution. The study illustrates relationships between measured hanging-wall overbreak, cablebolt orientation and stope type.     

Geochemical characterization of groundwater from shallow aquifer surrounding Fetzara Lake N. E. Algeria

Hydrogeochemical investigations were carried out around Fetzara Lake, Northeast Algeria, to assess the quality of groundwater for its suitability for drinking and irrigation purposes. The groundwater chemistry is mainly controlled by the water?Crock interactions, but also influenced by other processes such as evapotranspiration and ion exchange. Groundwater samples collected, during two periods (1993 and 2007) from wells in the area were analyzed for pH, EC, TDS, Ca²⁺, Mg²⁺, Na⁺, K⁺, CO ₃ ^2? , HCO ₃ ^? , Cl^?, SO ₄ ^2? , and NO ₃ ^? . The chemical relationships in Piper??s diagram and Gibbs??s diagram suggest that groundwaters mainly belong to noncarbonate alkali type and Cl^? group and are controlled by evaporation dominance, respectively, due to the sluggish drainage conditions, greater water?Crock interaction, and anthropogenic activities. A comparison of the groundwater quality in relation to drinking water quality standards proves that most of the water samples are not suitable for drinking. US Salinity Laboratory??s and Wilcox??s diagrams and %Na⁺ used for evaluating the water quality for irrigation suggest that the majority of the groundwater samples are not good for irrigation.     

Utilization of bituminous limestone ash from EL-Lajjun area in production of lightweight Masonry block

The following work aims at minimizing the environmental impact of the solid wastes (ash) that is produced after the utilization of the bituminous limestone in thermal power stations and/or retorting processes. The laboratory tests have been selected with respect to construction needs and possible post construction conditions. Utilization of the various types of ash in the production of lightweight concrete block has revealed optimum results. The compressive strength of various ash–glass sand mixes has ranged between 19 and 76 kg/cm² at 28 days. The compressive strength of ash–tuff mixes has ranged between 54 and 63 kg/cm² at 28 days. Ultra light mixtures using ash–polyester with a density of 0.88 kg/m³ and a compressive strength of 21 kg/cm² at 28 days are produced at normal room curing temperature without the use of ordinary Portland cement. The high alkalinity of El-Lajjun ash is considered a disadvantage when utilized in normal concrete mixes for structural purposes. Ash only can be mixed with aggregates to produce lean concrete for blinding purposes for use in foundations.     

Competence-based and game-based capacity development for sustainable water management in Germany

Sustainable water management is one of humanity’s most important challenges—today and in the future. Germany does not face a significant water shortage problem, but it has three main challenges: protection of water quality, ensuring public water supply and public wastewater disposal, and protecting the public and infrastructure from floods. Capacity development is a key issue to overcome the challenges of water resources in any country including Germany. Engineers, technicians, and mechanics need to upgrade their knowledge on a regular basis to deal with the complex management and rapid technological developments. In order to create efficient training schemes, the Vocational Training Working Group of Global Water Partnership (GWP), part of the GWP Capacity Development Task Force, has worked on the definition of fundamental job profiles for the Water and Sanitation Sector (WASS). To cover all technical functions of the industrial water cycle, it was necessary to identify around thirty occupations. Then, a competence-based training approach was adopted. Additionally, an assessment approach was also developed based on comparing the level of competence of the workers to a standard level of competence for each job. The RWTH Aachen University with its partners have developed another game-based approach (SeCom2.0) based on serious gaming technology to enable water professionals dealing with flood risk management to be trained on different flood situations in a virtual environment. SeCom2.0 has three main components that are connected by a database layer. In addition to the serious games component, there is a collaboration component and a learning management system. For nearly 100 members from the flood competence centre (HochwasserKompetenzCentrum) in Cologne, Germany gave input to simulate the real flooding scenarios, and the learners will have to deal with a flood scenario by protecting the city in a given time and using a given resources and tools. This work concluded that both competence-based and game-based approaches could be significantly improved by blending both approaches. This will improve the process of training; for example, the competence-based approach can be enriched by using game-based simulation by introducing the trainees to a simulation of different technologies in water utilities. This can save resources and money and enrich the training. More importantly is modifying the game-based approach using the approach of competence-based to focus on specific competencies and to make use of the competence standards in its assessment component. The first section of this introduces and categorizes water challenges in Germany. In the second and third section, the two approaches are introduced in details. The competence-based approach is introduced to the WASS while the games-based to the flood risk management. Finally, a conclusion and recommendations are illustrated.     

GIS-based approach for evaluating a community intrinsic resilience index

Natural Hazards - Community resilience refers to the degree to which a community can survive and recover following a disaster. While resilience itself is well understood, decisions that would...