Mineralogy and geochemistry studies on the Nusab El Balgum granitic batches,South Western Desert,Egypt

Igneous rocks of Nusab El Balgum are formed as an elongated complex mass covering an area of about 4 km?×?12.5 km (50 km²), in the NNE-SSW direction of the Tarfawi-Qena-South Sinai trend, which is a branch of the Trans-African shear zone at the intersection with the Kalabsha fault, which is a branch from Guinean-Nubian lineaments. The continuous reactivation of these two major weakness zones from the late Triassic to recent times has created many generations of the magma batches. The exposed granitic rocks of these batches at Nusab El Balgum were represented by the fresh peralkaline granite (youngest) and hydrothermally altered granites (oldest). The fresh peralkaline granite takes the form of a small stock composed essentially of perthites, quartz, sodic pyroxenes, amphiboles (secondary), and rare albite according to the proportion of presence, respectively. The accessory minerals are zircon, bastnaesite-(Ce), columbite-(Fe), magnetite, barite, and sphalerite. The geochemical study indicated that this granite is peralkaline, ferroan, A-type (specifically belongs to the A1-subgroup), anorogeny, emplaced in a within-plate, and crystallized at relatively shallow depth from the alkali basaltic magma similar to the OIBs. Furthermore, it is enriched in the HFSE (e.g., Th, U, Nb, REE, and Zr). The hydrothermally altered granites are formed as an incomplete ring shape and a small stock. They were formed during the late Cretaceous age and were altered due to the hydrothermal solutions from the continuous reactivation affected weakness zones and the new magmatic batches. The hydrothermally altered granites are extremely rich in HFSE found in the accessory minerals such as zircon (different in shape, size, and contains inclusions of bastnaesite and columbite), columbite-(Fe&Mn), rare gittinsite, pyrochlore minerals (ceriopyrochlore and plumbopyrochlore) carlosbarbosaite, changbaiite, bastnaesite-(Ce), monazite-(Ce), stetindite, cerianite-(Ce), thorite, and uranothorite. These rocks were subjected to many highly superimposed hydrothermal alteration types, including propylitic, sericitic, potassic, silicification, argillic, and Fe-Mn oxy-hydroxides. The hydrothermal solutions with low temperatures and containing F^1? and CO₃^2?, PO₄^3? and H₂O caused redistribution; transportation and redeposition of the HFSE in these rocks, in addition to the clay minerals and K-metasomatism, were formed. The relations between the silicification index (SI?=?SiO₂/(SiO₂ + Al₂O₃) and Zr, Nb, Th, U, LREE, and HREE are positive but they become negative with the K-metasomatism.     

Phosphorus dynamics and corn growth under applications of corn stalks biochar in a clay soil

Biochar prepared from corn stalks is used as a source of phosphorus in this study. The hypotheses were to investigate effects of biochar applications in clay soil on availability, changes of phosphorus pools and maximum adsorption of phosphorus as well as corn growth. The soil was placed in plastic pots with each contains 3 kg of this soil. Biochar was added at levels of 0 (control), 6.5 (B₁), 19 (B₂), and 38 (B₃) g pot^?1. In this experiment, the pot was planted with corn (Zea mays). The results of this study revealed that the biochar application enhanced available phosphorus (Olsen-P) from 11.51 to 17.10 mg kg^?1. Adding biochar significantly increased the amount of NH₄Cl-P, NaHCO₃-P_o, and NaOH I-P_o fractions (p?≤?0.05), but it significantly decreased HCl-P_i fraction (p?≤?0.05). Addition of biochar at the highest level increased the fresh and dry matter productions by up to about 75 and 48.7%, respectively, compared to the control. The phosphorus uptake by corn plants significantly increased with increasing levels of biochar. The removal efficiency (% sorption) and maximum adsorption (b) of phosphorus increased with increasing level of biochar addition compared to control. Consequently, it is recommended to add biochar produced from corn stalks to the soil in order to substitute phosphate fertilizers.     

A new look on Imperial Porphyry: a famous ancient dimension stone from the Eastern Desert of Egypt—petrogenesis and cultural relevance

International Journal of Earth Sciences - Imperial Porphyry, a famous dimension stone of spectacular purple color, was quarried in the Mons Porphyrites area north of Jabal Dokhan in the Eastern...     

Groundwater beneath the urban area of Khan Younis City,southern Gaza Strip (Palestine): hydrochemistry and water quality

Arabian Journal of Geosciences - This paper presents the results of a groundwater hydrochemical assessment in the urban area of Khan Younis City in the southern Gaza Strip by measuring its...     

Purang Ultramafic Complex and Their Geological Origin, Southwest Tibet

<正>Neoproterozoic ophiolitic Serpentinites are common in the Arabian–Nubian Shield(ANS)of the Eastern Desert(ED)of Egypt,which were formed in arc stage in different tectonic setting.Thus they might subject to exchange with the crustal material derived from recycling subducting oceanic lithosphere.This caused metasomatism enriching     

The Pan-African Ophiolites and Related Mineralization in Egypt

<正>Precambrian ophiolites are abundant in the ArabianNubian Shield of NE Africa and Arabia and range in age from 690 to 890 Ma.In Egypt,they are widely distributed in the central and southern Eastern Desert and occur as nape complexes along sature zone or dismembered masses in metavolcano-sedimenatry assemblages.The ophiolite     

Monitoring of Dead Sea water surface variation using multi-temporal satellite data and GIS

Remote sensing (RS) and geographic information systems (GIS) are very useful for environmental-related studies, particularly in the field of surface water studies such as monitoring of lakes. The Dead Sea is exposed to very high evaporating process with considerable scarcity of water sources, thus leading to a remarkable shrinkage in its water surface area. The lake suffers from dry out due to the negative balance of water cycle during the previous four decades. This paper discusses the application of RS, GIS, and Global Positioning System to estimate the lowering and the shrinkage of Dead Sea water surface over the period 1810–2005. A set of multi-temporal remote sensing images were collected and processed to show the lakes aerial extend shrinkage from 1973 up to 2004. Remote sensing data were used to extract spatial information and to compute the surface areas for Dead Sea for various years. The current study aims at estimating the fluctuation of Dead Sea level over the study period with special emphasis on the environmental impact assessment that includes the degradation level of the Dead Sea. The results indicated that there is a decrease of 20 m in the level of the Dead Sea that has occurred during the study period. Further, the results showed that the water surface area of the Dead Sea has shrunk from 934.26 km² in 1973 to 640.62 km² in 2004.     

Effect of animal borings on geotechnical properties of coralline limestone in NW Jeddah City, Red Sea Coast, Saudi Arabia

The coralline limestone covers large areas in the western and northern parts of Jeddah City. This coralline limestone is composed mainly of shelly limestone with pencil-sized animal borings. These borings increase the primary porosity and make the rock weak enough to have low-bearing capacity. The dry density (γ _dry) values of the study coralline limestone ranges from 1.54 to 2.09 g/cm³. The total porosity varies from 12.34 to 28.42 %. The absorption percentage fluctuates between 6.49 and 17.75 %. More than 95 % of the tested rock core samples have compressive strength less than 15 MPa. The compressive strength commonly decreased with the increase of animal borings. The obtained results cause the study coralline limestone weak enough to support heavy structures.     

Trend analysis of maximum,minimum, and average temperatures in Bangladesh: 1961–2008

The present study is about the analysis of mean maximum and mean minimum temperatures carried out on annual, seasonal, and monthly timescales examining the data from 15 meteorological stations in Bangladesh for the period 1961–2008. Various spatial and statistical tools were used to display and analyze trends in temperature data. ArcGIS was used to produce the spatially distributed temperature data by using Thiessen polygon method. The nonparametric Mann–Kendall test was used to determine whether there is a positive or negative trend in data with their statistical significance. Sen’s method was also used to determine the magnitude of the trends. The results reveal positive trends in annual mean and mean maximum temperatures with 95 % significance. Trend test reveals that the significant positive trend is found in June to November in case of mean maximum temperature, but according to the mean minimum temperature, the situation is different and a significant positive trend was found from November to February. The analysis of the whole record reveals a tendency toward warmer years, with significantly warmer summer periods and slightly colder winters. These warming patterns may have important impacts on energy consumption, water supply, human health, and natural environment in Bangladesh.     

Modified DRASTIC assessment for intrinsic vulnerability mapping of karst aquifers: a case study

Groundwater in karstic aquifers can be dangerously sensitive to contamination. In this paper, DRASTIC assessment was modified and applied, for the first time, to address the intrinsic vulnerability for karst aquifers. The theoretical weights of two of DRASTIC’s parameters (aquifer media and hydraulic conductivity) were modified through sensitivity analysis. Two tests of sensitivity analyses were carried out: the map removal and the single parameter sensitivity analyses. The modified assessment was applied for the karst aquifers underlying Ramallah District (Palestine) as a case study. The aquifer vulnerability map indicated that the case study area is under low, moderate and high vulnerability of groundwater to contamination. The vulnerability index can assist in the implementation of groundwater management strategies to prevent degradation of groundwater quality. The modified DRASTIC assessment has proven to be effective because it is relatively straightforward, use data that are commonly available or estimated and produces an end product that is easily interpreted.