46 research outputs found
The Origin and MgCl2–NaCl Variations in an Athalassic Sag Pond: Insights from Chemical and Isotopic Data
No full textThe examination of past and new chemical–isotopic data (2H/1H–18O/16O,11B/10B and87Sr/86Sr ratios) shows the meteoric origin of the Sawa Lake (Muthanna Governorate, Iraq) and its connection with the local aquifers, which feed the lake via the groundwater emerging from its floor through fault systems. The chemical and isotopic evaporation models are traced by geochemical computer codes by using a different composition of some potential inflows to the lake (e.g., the Euphrates River and Dammam aquifer). The main product of the chemical evaporation models is gypsum, as confirmed by the mineralogical examination of the sediment and the surrounding outcrops. A strong18O–2H enrichment is a consequence of the evaporation effect in arid regions; δ18O–Cl models and δ11B = + 23.4‰ exclude the contribution of any seawater-derived fluids. This latter value along with87Sr/86Sr = 0.707989 suggests a mixed origin from the Eocene–Miocene aquifers. The isotope and chemical evaporation paths from the meteorically recharged sources match the lake composition. However, compositional switches from NaCl toward MgCl2occurred in the last decade and are related to post-drought periods, showing that the interaction of the recharging waters with the local soils (Na–Mg exchange and/or the leaching of the top layer salts) have a role in the chemical composition. This demonstrates that the lake is significantly influenced by climatic variations
Mada'in Salih, a Nabataean town in north west Arabia: analysis and interpretation of the excavation 1986-1990
No full textThis research concerns Mada'in Salih, an archaeological site in north-west Saudi Arabia. Historically, it was part of the Nabataean kingdom which flourished in northwest Arabia (Jordan, parts of Syria, Palestine and some parts of Saudi Arabia), with Petra in Jordan as its capital. The Nabataeans were famous for their trading role, as they transported frankincense and myrrh and exported balsam and bitumen. They built monumental tombs in Petra and Mada'in Salih as well as other public buildings such as temples theatres and baths. They were also famous for their skills in hydraulic engineering and the production of very thin, distinctively painted pottery. Mada'in Salih was an important station on the trade route which linked south Arabia with Mediterranean countries. The main feature of the site is the monumental tombs, which are about eighty in number, some of them dated and bearing inscriptions. Those inscriptions are in Aramaic and usually contain information about the owner name, legal rights, and occasionally the mason's name. Little was known about the site's history and other aspects such as the economy, culture, society and religions prior to the excavation. Various questions were raised which the thesis attempts to address. The archaeological work conducted on the site included a survey, several trenches around the town wall and in front of some of the tombs as well as an excavation in the settlement area. The excavation revealed a private house which furnished us with information regarding house planning, building techniques and materials. A large amount of pottery, small finds and coins were recovered, studied and classified. The results added some information to what was already known about the Nabataeans in general and Mada'in Salih in particular. The site had witnessed its peak during the first century A.D. As most previous archaeological work had been carried out in the northern parts of the Nabataean kingdom, the results of this excavation are important for comparative studies between this, the largest Nabataean settlement centre in the south, to the centres of the north. The trade which had been an important factor in the establishment of the site declined when the trade route was shifted from land to sea by the Romans during the last half of the first century A.D
Chemical and isotope composition of the oilfield brines from Mishrif Formation (southern Iraq): Diagenesis and geothermometry
No full textThis paper focuses on the geochemical composition and isotope geochemistry of brines in the Cenomanian–Turonian carbonate Mishrif reservoir of southern Iraq. Main dissolved constituents, trace elements, δ2H and δ18O, 87Sr/86Sr, mineral saturation indices and thermodynamic calculations were investigated in formation waters from the Mishrif Formation to obtain a better understanding of brine evolution and diagenetic effects over geological time. Previous published δ11B data were also reinterpreted as a geothermometer tool. The results are compared with previous published data for local oilfields and coeval formations in the Arabian Gulf. The Mishrif brine has a marine origin and is diagenetically modified to Ca-excess and Na-deficit. Formation waters are quartz supersaturated and are in equilibrium with chalcedony and calcite-dolomite in the temperatures range of 50–75 °C, which is also confirmed by calcite-water oxygen isotope fractionation and δ11B geothermometer. The potential role of clays in conditioning brine chemistry during diagenetic processes was highlighted by activity diagrams; in particular, their adsorption/exchange effect on sodium could explain the lower temperature obtained by the Na/Li geothermometer (42 ± 6 °C). The δ2H and δ18O values show that oxygen isotope composition of the brines was isotopically more affected by interaction with limestone during diagenesis than seawater evaporation. The main effect is an 18O-enrichment on the brine starting from the SMOW value. Locally, dilution by present-day meteoric water was also detected (Rumaila South), which is shifted towards the local meteoric water line. The strontium isotope ratios range from 0.707713 to 0.707749 and correspond to a marine strontium of late Cenomanian–early Maastrichtian age, except for the Majnoon sample, which shows a more radiogenic value (0.708043). Radiogenic strontium and gypsum and anhydride saturation indices of the Majnoon sample could indicate the contribution of calcium and sulphate from the strontium-rich sulphate minerals of the Cambrian salt domes occurring in the oilfields of southern Iraq. The higher manganese concentration (4 mg/l) and the slightly higher temperature inferred by geothermometers (up to 74 °C) in comparison with present-day could indicate that the Majnoon brine is a hot fluid, probably related to a deeper structure such as the Zagros Foredeep Fault
“Amal-I Salih” As an Important Historical Source
No full textManuscripts play an important role to fill the gaps and disclose uncertain pages of history. They provide us with the information of witnesses and stories had happened prior to the author who had heard from contemporaries. Besides that, there are some manuscripts that were written by several authors and generations. The manuscript of “Amal-i Salih” is a two-volume source written by Muhammad Salih Kambu of Baburid period in India. The manuscript provides valuable information about political and diplomatic relations between Ashtarkhanids and India, information about the genealogy of the Ashtarkhanid dynasty, information about the representatives of the political, cultural, and spiritual spheres of Central Asia
Impact of North African Sand and Dust Storms on the Middle East Using Iraq as an Example: Causes, Sources, and Mitigation
No full textThis study aims to determine the reasons for the increase in the frequency of sand and dust storms in the Middle East and to identify their sources and mitigate them. A set of climatic data from 60 years (1960–2022) was analyzed. Sand storms in Iraq are a silty sand mature arkose composed of 72.7% sand, 25.1% silt, and 2.19% clay; the clay fraction in dust storms constitutes 70%, with a small amount of silt (20.6%) and sand (9.4%). Dust and sand storms (%) are composed of quartz (49.2, 67.1), feldspar (4.9, 20.9), calcite (38, 5), gypsum (4.8, 0.4), dolomite (0.8, 1.0), and heavy minerals (3.2, 6.6). Increasing temperatures in Iraq, by an average of 2 °C for sixty years, have contributed to an increase in the number of dust storms from 75 to 200 times annually. North African storms affect the Middle East, with a monthly average exceeding 300 g/m3 in peak dust seasons. To reduce the negative impacts on public health, property, and infrastructure, the study suggests solutions to mitigate them, including reducing carbon dioxide gas emissions to prevent the expansion of drought and the afforestation of the desert with plants adapted to drought using advanced techniques and avoiding land overuse
Geochemistry of Termite Hills as a Tool for Geochemical Exploration of Glass Sand in the Iraqi Western Desert
No full textA preliminary assessment of the geochemical factors affecting groundwater and surface water quality around the rural communities in Al-Anbar, Western Desert of Iraq
No full textGeochemistry and mineralogical composition of the airborne particles of sand dunes and dust storms settled in Iraq and their environmental impacts
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