Urban sprawl analysis of Akhmim city (Egypt) and its risk to buried heritage sites: insights from geochemistry and geospatial analysis
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Abstract The present study employs a multidisciplinary approach to highlight the risks of urban expansion on buried cultural heritage sites. The buried temple of Ramses II in Akhmim city was chosen as a case study to assess the impact of urban expansion on its preservation. Support Vector Machine (SVM) classification was utilized to analyze satellite images from multiple sensors and evaluate the extent of urban growth surrounding the temple. The study also incorporated petrographic and mineralogical analyses of statues discovered in the temple, along with calculations of saturation indices, to assess the potential interactions between groundwater and archaeological materials. The findings indicate that urban development is encroaching upon the temple, posing potential risks to its preservation. Saturation indices for minerals in groundwater indicate a high tendency to dissolve dolomite (a common mineral in limestone) and to precipitate halite (sodium chloride). This is a concern because the artifacts unearthed from the temple are primarily composed of limestone. Consequently, there is a risk to the artifacts due to erosion and disintegration caused by mineral crystallization and expansion, as evidenced by the analysis of the rock and mineral characteristics of the statues discovered in the temple. The study proposes protective measures for the temple, including defining its dimensions beneath the urban area and establishing a dedicated protection zone around it.Keywords:
Temple
Urban sprawl
Halite
Halite precipitation with water and air temperature was observed in detail,and homogenization temperature of fluid inclusions in halite formed in ancient and modem Chaka Salt Lake was studied.Halite precipitates mainly in August every year and largely precipitates between 13 and 15pm at one day when water temperatures reach 20℃but can seldom reach 30℃.Homogenization temperatures of fluid inclusions in halite formed in Chaka Salt Lake range from 14℃to 38℃with an average of 23.7℃.The number of inclusions appears an obvious peak value at homogenization temperatures between 18～25℃,which probably represent the water temperature in which halite mainly precipitates when water temperatures reach 20℃.Therefore,homogenization temperatures of fluid inclusions in halite formed in Chaka Salt Lake can well reflect the water temperature.
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Homogenization
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The general aim of this project was to identify whether microorganisms from salt-saturated brines are preferentially entombed inside halite brine inclusions. This involved direct comparison of microbial communities (Archaea and Bacteria) in in-situ brine and halite samples collected from Trapani Salterns in Sicily, as well as, comparison between parent brines and experimentally-entombed halite communities over a course of 21-weeks.
Quantification of archaeal and bacterial numbers showed that Archaea are exceptionally more abundant in both brine and halite, and that Bacteria are about 0.25% of the overall community in both conditions. Remarkably, few differences were observed in terms of abundance and community structure between communities in 21-week-old halite and those found in the parent brines. Evidently, all organisms of a mixed microbial community are entombed equally and most that are trapped in this way are capable of surviving inside halite for short to moderate lengths of time. This is presumably due to a complex web of interspecies interactions, co-operations and the sharing of usable metabolites.
Nevertheless, some organisms are poor survivors inside halite and showed a decrease in their relative abundance in halite. In this study, this was highlighted by the decreased abundance of Haloquadratum, Candidatus Nanosalina and Cyanobacteria VII inside halite.
Finally, comparisons made between communities from different Pond (brine) origins showed some significant differences and suggests that communities in halite can vary considerably depending on the environmental conditions (e.g. ionic composition and water activity) at the point of halite precipitation.
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Brine
Salt lake
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To investigate the possibilities of utilization of dolomite large size fractions (dropouts) and their effect on plants a five-year experiment was set in 2015. A fertilization value of large fractions (5–7 and 7–10 mm) of dolomite in two doses was studied. The biomass yield of crops in dolomite dropout treatment was around 90% from the treatment using dolomite flour (control). Losses of bases from the soil treated with high doses of dropouts did not exceed the migration losses of the treatment with dolomite flour. Dynamics of dolomite flour dissolution in the soil was empirically modeled. The data prove that high doses of the large-sized dolomite fractions act similarly to standard dolomite flour and have more persistent effects on soil and plants.
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ABSTRACT The experimental evaporation of brine in shallow vessels shows that layered halite can form by the overgrowth of crystals in mats that have foundered from their initial position of growth at the brine‐air interface; by the upward and lateral growth of crystals that have nucleated on the floor; and by the overgrowth on detrital halite. Each of these processes, and its resultant crystal fabric, is described in relation to the environmental factors which influence it. The fabrics of primary halite crystals in layered halite‐rock and associated deposits from the Lower Keuper Saliferous Beds of the Cheshire Basin are described and compared with those of the experimentally produced halite. Some of the ancient halite‐rock may be matched with floor‐nucleated crystals, and some with detrital halite; none can be shown to have grown from foundered mats. The halite‐rock is regarded as having formed in shallow brine bodies, perhaps only a few centimetres deep, but of unknown extent, whilst the presence of planar solution or deflation surfaces at the top of the layered units, and disruptions in bedding similar to buckled salt‐crust structures, point to periodic and perhaps prolonged emergence.
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Brine
Salt pan
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The subject of dolomite formation has always put researchers in the challenge. In this study, the origin of the dolomites of the Chorgali Formation near Chorgali Pass was explored through field observation, petrographic characteristics, mineralogical and geochemical analysis. Analytical analyses used in the present studies include XRD, SEM-EDS, and stable isotopes studies. The dolomites were categorized into three major genetic types based on their textural and structural features showing their distinct origins. These dolomites are named fine crystalline dolomite (Df), medium crystalline dolomite (Dm), and coarse crystalline dolomite (Dc). The analytical approaches linked with field observations and petrographic examinations identified that; the first type of dolomites (i.e., Df) is related to the early stage of diagenesis and contain the presence of mineral dolomite (40%), gypsum (27%), quartz (17%) and albite (16%) and are low stochiometric low ordered in character as recognized by XRD results. The SEM-EDS analysis identified low Mg, Ca, O, Na, Si, and Fe concentrations. Further, the stable isotopes (δ18O) values for Df (i.e., -5.95 to -396‰V-PDB) are less depleted. Moreover, Dm and Dc revealed 100% mineral dolomite and are stochiometric ordered dolomites. High concentrations of Mg, Ca and O are observed in Dm and Dc respectively. Stable isotopes (δ18O) result in exhibiting highly depleted values for Dm (-7.947‰V-PDB) and Dc (-9.227 to -8.302‰V-PDB) showing its formation with the elevated temperature at depth. In addition, δ13C values of Df, Dm, and Dc lie in the range of the original marine signature of Eocene times.
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Qinghai Lake is the largest inland saline lake in China.In order to search for the mechanism of dolomite formation,a sediment column with 25 cm long was collected from the bottom of the lake at approxmately 15 km north to the Erlangjian.It has been discovered that there is 2.2% dolomite in the sediments through the analysis of X-ray diffraction.Some researchers also reported a 10% dolomite content in the sediments.SEM images show that the dolomite take the shape of the spheric aggregations with the diameter of 1—2 μm,associated with the pyrite aggregations at the similar size.The characteristics of these dolomite and pyrite aggregations are very similar to those microbal origin of dolomite discovered in the modern high saline lagoons and tidal flats.This is the first discovery of this kind of dolomite in the inland lake with low salinity,which is high significant to search the mechanism of dolomite formation and to understand the famousdolomite problem.
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Primary fluid inclusions in halite crystallized in Saline Valley, California, in 1980, 2004–2005, and 2007, contain rod- and coccoid-shaped microparticles the same size and morphology as archaea and bacteria living in modern brines. Primary fluid inclusions from a well-dated (0–100,000 years), 90 m long salt core from Badwater Basin, Death Valley, California, also contain microparticles, here interpreted as halophilic and halotolerant prokaryotes. Prokaryotes are distinguished from crystals on the basis of morphology, optical properties (birefringence), and uniformity of size. Electron micrographs of microparticles from filtered modern brine (Saline Valley), dissolved modern halite crystals (Saline Valley), and dissolved ancient halite crystals (Death Valley) support in situ microscopic observations that prokaryotes are present in fluid inclusions in ancient halite. In the Death Valley salt core, prokaryotes in fluid inclusions occur almost exclusively in halite precipitated in perennial saline lakes 10,000 to 35,000 years ago. This suggests that trapping and preservation of prokaryotes in fluid inclusions is influenced by the surface environment in which the halite originally precipitated. In all cases, prokaryotes in fluid inclusions in halite from the Death Valley salt core are miniaturized (<1 μm diameter cocci, <2.5 μm long, very rare rod shapes), which supports interpretations that the prokaryotes are indigenous to the halite and starvation survival may be the normal response of some prokaryotes to entrapment in fluid inclusions for millennia. These results reinforce the view that fluid inclusions in halite and possibly other evaporites are important repositories of microbial life and should be carefully examined in the search for ancient microorganisms on Earth, Mars, and elsewhere in the Solar System. Key Words: Ancient prokaryotes—Death Valley—Fluid inclusions—Halite—Saline Valley—Starvation survival. Astrobiology 9, 467–482.
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Time-of-Flight–Secondary Ion Mass Spectrometry (ToF-SIMS) using a bismuth liquid metal ion source was utilized to characterize and image microbial biomarkers within dolomite from early-middle Miocene coastal mud volcano outcrops in Kuwait. ToF-SIMS analysis revealed biomarkers of ancient microbial consortia of sulfate reducers and methane oxidizers participating in the anaerobic oxidation of methane. The identified lipid biomarkers comprised 17α(H),21β(H)-Norhopane, Hop-17(21)-ene or Hop-22(29)-ene (diploptene), non-isoprenoidal dialkyl glycerol diethers (DAGEs), and Diacylglycerol esters (DGs). The ion µ-scale images of carbonate rocks showed two characteristic styles: (1) high signal intensity of dolomite, halite, and biomarkers, where the biomarkers demonstrate a distinctive co-localization pattern with both dolomite and halite; and (2) a lack of dolomite, halite low signal intensity, and an absence of biomarker co-localization patterns. Our results highlight three remarkable observations. Firstly, the concomitance of dolomite and halite suggests a common source of magnesium and sodium supply, likely from the hypersaline Al-Subiya sabkha. This emphasizes the importance of hypersaline seawater for dolomite formation. Secondly, microbial biomarkers correspond to methane- and sulfate-rich conditions under which dolomite was formed. Lastly, the high intensity of biomarker signals and their association with dolomite and halite indicate that the consortia involved in dolomite formation have preferences for high-salinity conditions. The three observations align with previous studies that have highlighted the importance of methane-sulfate redox, high salinity, and halophilic microbes for dolomite formation. This work is the first to acknowledge ancient microbial biomarkers within Miocene dolomite in Kuwait, which aims to broaden the understanding of the biogeochemical processes triggering dolomite formation in similar environments and ancient geologic settings.
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Sabkha
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Halite has crystallized at the 30℃ and 52℃ isothermal evaporations in lab from brine of Lop Nor salty lake, Xinjiang, China. And the plenty of liquid-phase inclusions occur in the halites. The homogenous temperatures of liquid-phase inclusions in halite is measured. The results show that only few temperature data of liquid-phase inclusions are close to 30℃ and 52℃ temperatures of brine, but most of the temperatures are by 20 - 90 ℃ higher than the fixed temperatures, a few are by 6 - 30℃ lower than those. In addition, the homogenous temperatures of natural halite from salty lake of Lop Nor also show the similar case, i. e. , most of them are obviously away from the possible temperature of the halite-crystallizing brine. These materials show that they are influenced by a few factors. Therefore, the homogenous temperature of liquid-phase inclusions in halite must be carefully applied in determining the temperatures of paleo-lake water or medium; only through the synthetic analysis, are the reliable information obtained.
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Brine
Isothermal process
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Abstract The inhibition of halite mineral scale formation in oil and gas production is notoriously difficult. High concentrations of halite inhibitors always provide limited inhibition performance. In addition, it is extremely difficult to test halite formation and inhibition in the lab. In this paper, the dynamic halite loop has been developed to test halite formation and inhibition. Halite formation and inhibition were tested under both traditional static conditions and newly developed dynamic conditions. The results showed inconsistencies based on static jar tests and dynamic loop tests. The possible mechanisms of halite inhibition are discussed. The following conclusions have been drawn: Compared with the traditional static jar test, dynamic halite loop tests are more representative of halite formation in the field conditions and showed good reproducibility.The newly developed scale inhibitor demonstrated dynamic inhibition performance towards halite formation. Efficiency loop tests showed that the minimum inhibitor concentration (MIC) is less than 200ppm to inhibit halite formation effectively under the test conditions.
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Static testing
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