New occurrence of potential phosphate resource in northeast Jordan

An exploration program aided by field investigation, exploration drilling, detailed sampling, lithological and petrological studies, geochemical investigation, and resource calculation leads to the discovery of a potential phosphate resource in northeast Jordan close to the international border with Saudi Arabia and Iraq. The studied phosphate is of the Middle Eocene age that belongs to the Wadi Shallala Formation. It is equivalent to the phosphate deposits recorded in the lower part of the Umm Wual Formation in the Turayf region of Saudi Arabia and the Eocene Ratga Formation in the Ethna phosphate deposit west of Iraq. The phosphorites in the region are broadly similar in mineralogical composition and geochemical affinities. X-ray diffraction indicates the presence of francolite with variable amounts of calcite and quartz. Most samples consist of phosphate clasts embedded in carbonate and silica matrix and cement. P₂O₅ content is up to 32.3 % with an average equal to 18.6 %. The impurity is caused by the presence of variable amounts of SiO₂ and CaO. The F% and F/P₂O₅ ratio in studied phosphates is lower compared with that in phosphates from Jordan and Saudi Arabia. The geological and geochemical results were integrated for resource estimation. Three high-grade phosphate layers with ≥23 % P₂O₅ were considered in the calculations. The phosphate resource is classified as an inferred resource. The total volume of the resource is about 649 million tons. The average P₂O₅ content is 24.57, and the stripping ratio is 1:5.8.     

Groundwater potential assessment in a sedimentary terrain,southwestern Nigeria

Geoelectrical resistivity techniques are increasingly being applied in addressing a wide range of hydrological, environmental, and geotechnical problems. This is due to their effectiveness in near-surface characterization. In the present study, a suite of vertical electrical soundings (VESs) was integrated with 2D geoelectrical resistivity and time-domain induced polarization (IP) imaging to characterize the near-surface and delineate the underlying aquifer in a sedimentary terrain. The geophysical survey was conducted as part of preliminary studies to evaluate the potential of groundwater resource in Iyana-Iyesi and Canaan Land area of Ota, southwestern Nigeria. A high-yield confined sandy aquifer overlain by a low-yield aquitard was delineated; overlying the aquitard is a very resistive and thick layer that is predominantly composed of kaolinitic swelling clay intercalated with phosphate mineral.     

Relationships among volcanic and hydrothermal activity and faults from the Shunnan 3-D well zone in the Tadong Area (Tarim Basin,China)

Tarim Basin distributed widely two stages of Permian volcanic rocks. However, the location and timing of these rocks pinching out and the relationship between Ordovician carbonate hydrothermal reservoirs and fault activity remain unclear. The Shunnan (Shunnan here in after referred to as SN) 1 3-D well zone in the eastern Tarim Basin contains volcanic rocks, and the Ordovician layer contains a hydrothermal reservoir. This paper describes the lithology, stage, volcanic rock distribution, crater position and deposition pinch-out line of volcanic rocks based on drilling and 3-D seismic data. The Permian strata in the well zone contain only one stage of Kupkuciman Formation basalt and tuff, the Kaipeleicike Formation contains terrigenous clastic rock and the adjacent volcanic rocks of wells SN2 and GL (Gulong here in after referred to as GL) 2 exhibit an absence of deposition. Although the craters are distributed on both sides of the NNW faults that cross well SN4, their positions are also controlled by the intersection of earlier NEE and NW faults and later NNE faults. Furthermore, the Ordovician strata in the SN1 well zone developed abundant tubular high-amplitude anomalies and tabular high-amplitude anomalies via hydrothermal corrosion, and the anomaly distributions are similar to the positions of the craters, which are controlled by the intersection of multi-group faults and the density of the faults.     

Bioadsorption by sugarcane bagasse for the reduction in oil and grease content in aqueous effluent

Several techniques have been used to reduce the oil and grease content in aqueous streams; one excellent is bioadsorption. With a view to provide a sustainable method for the treatment of oily effluents, the aim of this study was to evaluate sugarcane bagasse as bioadsorbent to reduce the oil and grease content of aqueous effluents. Analysis of the material was performed, and the adsorption experiments were in a batch system, using a synthetic effluent. The results showed that the kinetic equilibrium occurred in 0.08 h of contact. The study of influence of pH of the aqueous phase and the temperature showed that the adsorption capacity was proportional to the pH value, but inversely proportional to the temperature. The adsorption isotherm was obtained at a temperature of 298.15 K using the Langmuir and Langmuir–Freundlich models, and the maximum adsorption capacity obtained was 6.65 kg of hydrocarbon per kg of bioadsorbent. It was verified that sugarcane bagasse represents an excellent material for application in the treatment of oily aqueous effluents, since it is associated with low cost and a high adsorption capacity. The variation in the adsorption capacity observed as a function of pH of the aqueous phase was not found to be significant. This is an important characteristic of the material in terms of its industrial application, verifying the possibility for its implementation in any treatment process, demonstrating the great potential of sugarcane bagasse for use as a sustainable alternative in the reduction in oil and grease in aqueous effluents.     

Research on comprehensive carrying capacity of Beijing–Tianjin–Hebei region based on state-space method

Based on state-space method and component analysis, this paper builds a comprehensive evaluation system of carrying capacity for the Beijing–Tianjin–Hebei region from four aspects, namely economy, environment, ecology and energy. The results show that the comprehensive carrying capacity in this region gradually rises in recent years and the economic carrying capacity plays an important role in this situation. Ecological and environmental carrying capacity are gradually enhanced but still affected by water shortages. The energy carrying capacity of this region is low, which is the major factor restricting its sustainable development. Based on the empirical results, following policy suggestions should be adopted: Firstly, local government should accelerate technological progress, promoting the optimization and upgrading of industrial structure; Secondly, the contradiction between supply and demand of water resource should be solved gradually; thirdly, government should develop recycling economy, realizing the coordinated development of economy and environment; last but not least, saving energy and improving energy efficiency.     

Automatic identification of fake patterns caused by short-width wavelets in seismic data

Despite the popularity of using the Haar wavelet filter in many applications, it sometimes introduces fake patterns into the multi resolution analysis (MRA) of seismic data. In this work, we compared different wavelet filters to demonstrate that these patterns are fake and not part of the original waveforms and to show that they are a result of using the Haar wavelet filter as a short-width wavelet. To achieve this, many seismic waveforms from two different sources: the Egyptian National Seismic Network (ENSN) and the High Sensitivity Seismograph Network Japan (Hi-net) are used with different wavelet filters. We propose an algorithm based on an autoregressive (AR) model to detect these patterns automatically and fully.     

Geochronological and isotopic records of crustal storage and assimilation in the Wolverine Creek–Conant Creek system,Heise eruptive centre,Snake River Plain

Understanding the processes of differentiation of the Yellowstone–Snake River Plain (YSRP) rhyolites is typically impeded by the apparent lack of erupted intermediate compositions as well as the complex nature of their shallow interaction with the surrounding crust responsible for their typically low O isotopic ratios. A pair of normal-δ¹⁸O rhyolitic eruptions from the Heise eruptive centre in eastern Idaho, the Wolverine Creek Tuff and the Conant Creek Tuff, represent unique magmatic products of the Yellowstone hotspot preserving abundant vestiges of the intermediate differentiation steps leading to rhyolite generation. We address both shallow and deep processes of magma generation and storage in the two units by combining high-precision ID–TIMS U–Pb zircon geochronology, trace element, O and Hf isotopic studies of zircon, and Sr isotopic analyses of individual high-Mg# pyroxenes inherited from lower- to mid-crustal differentiation stages. The zircon geochronology confirms the derivation of both tuffs from the same rhyolitic magma reservoir erupted at 5.5941 ± 0.0097 Ma, preceded by at least 92 ± 14 ky of continuous or intermittent zircon saturation approximating the length of pre-eruptive magma accumulation in the upper crust. Some low-Mg# pyroxenes enclosing zircons predate the eruption by at least 45 ± 27 ky, illustrating the co-crystallisation of major and accessory phases in the near-liquidus rhyolitic melts of the YSRP over a significant period of time. Coeval zircon crystals are isotopically heterogeneous (two populations at εHf ~?5 and ?13), requiring the assembly of isotopically distinct melt pockets directly prior to, or during, the eruption. The primitive Mg# 60–90 pyroxenes are out of isotopic equilibrium with the host rhyolitic melt (⁸⁷Sr/⁸⁶Sr_i = 0.70889), covering a range of ⁸⁷Sr/⁸⁶Sr_i = 0.70705–0.70883 corresponding to ratios typical of the most radiogenic YSRP basalts to the least radiogenic YSRP rhyolites. Together with the low εHf in zircon, the Sr isotopic ratios illustrate limited assimilation dominated by radiogenic Archean crustal source materials incorporated into variably evolved YSRP melts as they progress towards rhyolitic compositions by assimilation–fractional crystallisation.     

Comprehensive analyses of the initiation and landslide-generated wave processes of the 24 June 2015 Hongyanzi landslide at the Three Gorges Reservoir,China

Reservoir landslides pose a great threat to shipping safety, human lives and properties, and the operation of the hydropower station. In this paper, the 24 June 2015 Hongyanzi landslide at the Three Gorges Reservoir is considered as an example to study the initiation mechanism and landslide-generated wave process of a reservoir landslide. The finite difference method and limit equilibrium analysis are used to analyze the deformation and failure characteristics of the Hongyanzi slope. Simulation results show that a large deformation (about 358 mm) happens in the shallow deposits under intermittent rainfall condition, and the slope is in a limit state. At the same time, continuous rapid drawdown of the water level (about ?0.55 m/day during 8–24 June 2015) reduced the support and accelerated the drainage of the water for the bank slope. A coupling effect of intermittent rainfall and rapid drawdown of the water level was the triggering factor of the 24 June Hongyanzi landslide. Landslide-generated wave process was simulated using a fluid–solid coupling method by integrating the general moving object collision model. Simulation results show that the landslide-generated wave is dominated by the impulse wave, which is generated by sliding masses entering the river with high speed. The maximum wave height is about 5.90 m, and the wave would decay gradually as it spreads because of friction and energy dissipation. To prevent reservoir landslides, the speed for the rising or drawdown of the water level should be controlled, and most importantly, rapid drawdown should be avoided.     

Indirect unstructured hex-dominant mesh generation using tetrahedra recombination

Corner-point gridding is widely used in reservoir and basin modeling but generally yields approximations in the representation of geological interfaces. This paper introduces an indirect method to generate a hex-dominant mesh conformal to 3D geological surfaces and well paths suitable for finite-element and control-volume finite-element simulations. By indirect, we mean that the method first generates an unstructured tetrahedral mesh whose tetrahedra are then merged into primitives (hexahedra, prisms, and pyramids). More specifically, we focus on determining the optimal set of primitives that can be recombined from a given tetrahedral mesh. First, we detect in the tetrahedral mesh all the feasible volumetric primitives using a pattern-matching algorithm (Meshkat and Talmor Int. J. Numer. Meth. Eng. 49(1-2), 17–30 2000) that we re-visit and extend with configurations that account for degenerated tetrahedra (slivers). Then, we observe that selecting the optimal set of primitives among the feasible ones can be formalized as a maximum weighted independent set problem (Bomze et al. 1999), known to be \(\mathcal {N}\mathcal {P}\)-Complete. We propose several heuristic optimizations to find a reasonable set of primitives in a practical time. All the tetrahedra of each selected primitive are then merged to build the final unstructured hex-dominant mesh. This method is demonstrated on 3D geological models including a faulted and folded model and a discrete fracture network.