Bulletin of the Mineral Research and Exploration (BMRE)
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Mineralogical examination of biomass ashes: A preliminary study for potassium enrichment and phosphoric acid (H3PO4) production
No full textIn this study, biomass fly ash was investigated and determined by XRD (XRay Diffractometer) to be predominantly langbeinite, aphthitalite, sylvine, apatite and hydroxyapatite. An alkaline leaching study was carried out on the material in a glass reactor at l/s ratio 4 temperature 60°C at pH 12.85 and after drying was analyzed by ICP (Inducted couple plasma). The crystal structure composition of K2SO4 72.28% and potassium content of 33.47% (w/w) was recovered. The elemental transformations in this leaching process were: K 74.16%, Mg 0.55% was found to be 0.8%. It was found that a minimum of 4.84 g H2SO4 per 100 g fly ash was required to precipitate the Ca(OH)2 migrated into the liquid solution and the overall leaching efficiency was found to be 29.85%. In the alkaline leaching process, potassium was found to be easily recovered from each biomass ash. By adding 40 g H2SO4/100 g biomass waste remaining after leaching, a phosphorus recovery of 74.9% was observed. In this preliminary study, unsatisfactory results were obtained in obtaining the industry standard H3PO4. The reason for this is that the Al, Mg and K in the fly ash are subject to selective dissolution as a result of working at high pH in the alkaline leaching process
Tectono-stratigraphy, formation and emplacement ages of the Beyşehir-Hoyran Nappes in the south of the Sultan Dağları (Isparta, SW Türkiye)
No full textThe Beyşehir-Hoyran Nappes (BHN), in the south of Sultan Dağları, consist of ophiolite, mélange and nappe slices of different lithologies and ages belonging to the oceanic crust and related rocks, which originated from the northern Neotethys and were thrusted southwards over the Taurus Platform. These nappes, namely the Marmaris Ophiolite Nappe, the Gülbahar Nappe and the Domuzdağ Nappe, are represented by three tectonically related Nappe-slices that extend as a narrow NW-SE trending belt to the south of the Sultan Dağları. The Marmaris Ophiolite nappe (Upper Cretaceous) is formed by three subunits namely the Marmaris Ophiolite, the Kızılcadağ Mélange and the Yenicekale metamorphics. Hornblende minerals from amphibolites of the Yenicekale metamorphic rock unit yielded a 40Ar-39Ar age of 93.9±0.34 Ma (Cenomanian-Turonian boundary). In addition, the Middle Triassic-Early Jurassic Orluca Formation of the Gülbahar nappe is mapped for the first time in the Sultan Dağları region. Paleontological and radiometric ages obtained from this study show that the formation of the BHN should began in the Turonian and ended in the Late Maastrichtian. The nappes, on the other hand, were emplaced over southern Sultan Dağları in the early-middle Paleocene and reached their present position as a result of late Eocene movements
The genesis of Mordenite occurrences: Diagenetic and hydrothermal alteration processes of Paleocene volcanics in Ilıca (Yıldızeli), Türkiye
No full textDifferent geological processes such as weathering, diagenesis in hydrological systems, hydrothermal processes and contact metamorphism have been proposed to explain the genetic relationships of mordenite occurrences. The mineralogical and genetic analyses in this study are essential for identifying alteration minerals and assessing reaction processes. The Yıldızeli region, located south of the İzmir-Ankara-Erzincan suture zone and northeast of the Kırşehir block, is significant for its mineral deposits. This area consists of Paleocene-Miocene volcano-sedimentary units. Analyse results of selected zone mordenite samples from the Paleocene volcanic units that host mordenite mineralization are linked to low-grade metamorphism, particularly associated with zeolite facies (150-300 °C, 1-3 kbar and pH 4-7), following tectonically controlled hydrothermal alteration. The zeolitization process involves interacting fluids crucial for mobilizing alkali elements, with compositional variations in mordenite indicating a continuous evolution toward equilibrium conditions under decreasing temperatures. The progression from mordenite to smectite, along with associated kaolinite occurrences, can be attributed to the hydrothermal circulation of alkaline waters and sodium extraction from underlying evaporites
Magmatic significance and hydrothermal alteration of layered chromitites from the Bracco Gabbro Complex, Ligurian Ophiolites, Italy
No full textThe Bracco chromitites are hosted in the Mesozoic Ligurian Ophiolites (Italy) and provide key insights into the magmatic and post-magmatic (i.e. metamorphic and hydrothermal) evolution of gabbro-hosted chromitites in an oceanic mantle. Petrographic and mineralogical analyses reveal that the Bracco chromitites comprise cumulitic, massive to disseminated, layered chromitites overprinted by multi-stage alteration within altered olivine–clinopyroxene–anorthite cumulates. Detailed Cr–Al– Fe³+ systematics indicates that primary Cr- to Al-rich chromite, affected by metamorphic-hydrothermal processes under sub-greenschist facies conditions, locally escaped recrystallization and metasomatic modification. Consequently, chromite cores preserve their primary magmatic compositions consistent with crystallization from aluminous melts produced by low-degree partial mantle melting at a midocean ridge (MOR) setting. Metamorphic-hydrothermal alteration is marked by multi-stage ferrian chromite rims, whereas based on their Mg content the associated chlorite is classified as clinochlore. Chlorite geothermometry indicates alteration temperatures in the range of ~100-300 °C, consistent with oceanic serpentinization under prehnite-pumpellyite facies conditions. The hydrothermal fluids were oxidizing, enriched in SiO2 and MnO, and circulated through fracture networks in the shallow oceanic lithosphere. Elevated MnO amounts in alteration rims suggest widespread Mn-enrichment in these fluids, potentially linking them to seafloor Mn deposits in the Ligurian Ophiolites. Together, these findings indicate that the Bracco chromitites, their gabbroic hosts, and associated lherzolitic mantle rocks were at least partially exposed at the Tethyan seafloor prior to their final emplacement during the Alpine orogenetic phase, where serpentinization promoted complex chromite alteration
Investigation of local soil properties of Erzurum province (Eastern Türkiye) by Horizontal/Vertical Spectral Ratio method
No full textErzurum province is a basin developed under the effect of strike-slip faults in the Eastern Anatolia region. The province is generally influenced by the left strike-slip Erzurum Fault Zone, the leftstrike- slip Aşkale fault, and the Başköy-Kandilli reverse fault. It is also located approximately 80 km from the Karlıova joint, which is the intersection of the North Anatolian and East Anatolian Faults. When the earthquakes of the instrumental and historical periods are analyzed, it is seen that many damaging earthquakes of medium to large magnitude have occurred in the Erzurum province. The Erzurum Basin is generally covered with old alluvium at the edges of the plains, while the flat areas in the central parts are covered with new alluvium. Determination of local soil properties in regions with high seismic hazard plays an important role in reducing earthquake risk. For this purpose, single station microtremor measurements were applied at 25 sites in Palandöken and Yakutiye districts of Erzurum province. The measurements were taken for at least 30 minutes and evaluated by using the Horizontal (H)/ Vertical (V) Spektral Ratio (HVSR) method. As a result of the analysis, the dominant period, H/V ratio and vulnerability index (Kg) values of the measurement points were calculated. The period values obtained vary between 0.15 s and 3.7 s, while the H/V ratios are between 2.2 and 8.5. The Kg value obtained using these parameters is defined as the vulnerability of the soil. It is concluded that high period, high H/V and high Kg values are obtained in areas with recent alluvium and multidisciplinary analyses should be performed in soil investigations in these regions
Pegmatites and alkali feldspar granites as sources of industrial K-feldspar: A study from Borucu, Aksaray, Central Türkiye
No full textThe Borucu (Aksaray) region, within the Central Anatolian Crystalline Complex, comprises a variety of rocks, including granite, alkali feldspar granite (AFG), pegmatite, and aplite dikes. The granite and AFG host some veins or lenses of pegmatites, with lengths reaching approximately 70 m in the N10-25W direction. The AFG and pegmatitic rocks are characterized by variable mineral assemblages, including K-feldspar (orthoclase), quartz, plagioclase, and to a lesser extent, biotite, garnet, and opaque minerals. Inner zones feature the mega-grained pegmatite, whereas outer zones consist of the coarse-grained K-feldspar and quartz pegmatite. In this study, integrated surface and vertical (trenching and drilling) exploration, mineralogy-petrography, geochemical, and magnetic separation analyses were employed to assess the industrial raw material potential of the AFG and pegmatites. The total alkali (Na2O+K2O) contents reach 15.56-16.82% for the mega-grained pegmatite, 8.07-9.76% in the coarse-grained pegmatite, and 9.20-9.66% in the AFG. However, the Fe2O3 contents (0.30-1.15%) constrain their industrial raw material quality. Magnetic separation improved the AFG material to second-quality ceramic industry standards. Despite Fe2O3 limitations, Borucu’s pegmatites and AFG represent usable industrial raw material resources
Effect of degree of saturation on consolidation parameters of fine-grained soils
No full textTerzaghi (1943)’s theory of consolidation phenomenon has some limitations for unsaturated geological environments in nature. Additionally, soils are subjected to consolidation tests under partially saturation conditions. The scope of this study is to illustrate the effect of degree of saturation (Sr) on the consolidation parameters using remolded soil samples. For this purpose, swelling pressure, compression index (cc), re-compression index (cr), coefficient of consolidation (cv), and pre-consolidation stress (σp’) were determined for the samples having different degrees of saturation and plasticity (PI). The consolidation parameters obtained from “undersaturated” remolded samples with varying degrees of saturation were compared with the consolidation parameters obtained from “fully saturated” remolded samples to illustrate which parameters of consolidation are affected most by the degree of saturation. The effect of swelling of partially saturated samples was eliminated prior to conducting oedometer tests. Results indicated a meaningful relationship between the compression index and the degree of saturation, though the relationship with the recompression index was less certain. Pre-consolidation stress generally decreased as saturation increased, while no definitive trend was observed between the degree of saturation and the consolidation coefficient. Overall, most consolidation parameters were found to be somewhat affected by the degree of saturation
Soil remediation at coastal plains with the help of DC Resistivity Method
No full textThe coastline of the Dardanos, a district of Çanakkale, Türkiye, suffers from saltwater intrusion due to excessive extraction of groundwater for domestic usage and also agricultural activities. Thus, the salinity level increased, and much of the land became unusable. The electrokinetic remediation method was employed to reduce the salinity level in the soil samples in laboratory conditions. The sample used in remediation is silty agricultural soil, with pH value and electrical conductivity (EC) of which are 8.33 and 1282 μS/cm respectively. In the lab-scale experiments, three different types of electrodes, aluminum, copper, and galvanized steel, were used in the tests. For each type of metal, electrode pairs were placed in the soil that was filled in a plastic container. Current variation was monitored while 1 VDC/cm was applied to electrodes. Average electrical conductivity reduces to 13.5%. As a side effect, all electrodes suffered from heavy corrosion which may be prevented by using anti-corrosion additives to reduce damage for future applications
Rare Earth Element Potentials of Red-Colored Eocene Kazmaca and Late Eocene–Early Miocene İncik and Bayındır Formations (Kırıkkale, Türkiye)
No full textThered-colored sedimentary rocks of the Kazmaca, İncik, and Bayındır formations, particularly the red mudstones, exhibit noteworthy enrichment in Rare Earth Elements (REEs) and uranium. These finegrained units were deposited in low-energy lacustrine to shallow-marine environments, where redoxsensitive geochemical processes played a central role in elemental mobilization and accumulation. Mineralogical and geochemical analyses, including XRD, XRF, and ICP-MS, identified the uraniumbearing mineral Fourmarierite, confirming the presence of uranium mineralization. This finding is supported by elevated Cu/Al ratios, increased Fe concentrations, and trace-element distributions indicative of a redox-controlled diagenetic environment. The high Fe concentrations and Cu/Al ratiosact as geochemical proxies for REE-hosting phases. The depositional setting, characterized by low dissolved oxygen levels, likely reflects a warm and humid paleoclimate that enhanced chemical weathering and facilitated the mobilization and subsequent precipitation of uranium and REEs. Notably, dark-colored mudstone interbeds within the sandstone sequences exhibit localized uranium accumulation, which may represent precursor zones for secondary REE mineralization. These findings underscore the importance of redox conditions and climatic factors in controlling REE and uranium enrichment in red bed sequences. The presence of Fourmarierite, in conjunction with distinctive geochemical signatures, suggests a significant potential for REE exploration in these formations
Evaluation of radioactive properties and microfaunal evidence in the Bosphorus and the Dardanelles straits and Golden Horn sediments
No full textThe aim of this study is to investigate radioactive pollutants from pollution loads transported from the Black Sea to the Aegean Sea by the Turkish Straits System and their effects on microfauna (benthic foraminifer and ostracod) assemblages. In the study, the effects of gross alpha and beta activity on the species number, species diversity, dominant species and species richness of benthic foraminiferal and ostracod assemblages were investigated in 16 bottom sediments taken from different depths in the Golden Horn, Bosphorus and Dardanelles straits. In the studied sediment samples examined 61 genera and 64 species of benthic foraminifera, 23 genera and 26 species of ostracoda were identified. In addition two migratory foraminifera species were observed as Spiroloculina antillarum of Atlantic-Pacific origin and Peneroplis pertusus of Indo-Pacific origin. A relationship between the abundance of microfauna and high gross alpha and beta values was found in the Dardanelles samples, but not in the Bosphorus and Golden Horn samples. In this study, the highest radioactivity value was observed in the deepest bottom sediment samples. Consequently, the gross alpha and beta values were seen to be close to each other in the Dardanelles Strait and Golden Horn samples, and they had a broad-spectrum in the Bosphorus samples