Petrology and Geochemistry

Since 50 years copper-silver ores have been extracted from the Lubin-Sieroszowice deposit located on the border between the Lower and Upper Permian sediments. It is a world class stratoidal type deposit. In the whole world the Kupferschiefer unit is recognized as a black, clayey organic-rich shale. The Cu-Ag deposit is a part of the Fore-Sudetic Monocline, and is located on the border of the Lower and Upper Permian strata The monocline includes three rock complexes. The first is the basement, which comprises Proterozoic crystalline rocks and Carboniferous sediments. It is overlain by monoclinally dipping Permian and Triassic sedimentary rocks. In this work, study on ore mineralisation of the red variety of the Kupferschiefer are presented. Oxidation of the Kupferschiefer as an epigenetic phenomena.The oxidized zones reveal low concentrations of simple copper sulphides with the dominating chalcopyrite accompanied by bornite, pyrite, covellite, galena, clausthalite, chalcocite, digeni...

Resolution for a local earthquake arrival time and ambient seismic noise tomography around the Eyjafjallajökull volcano Á. Benediktsdóttir (1), Ó. Guðmundsson (2), A. Tryggvason (2), R. Böðvarsson (2), B. Brandsdóttir (3), K. Vogfjörð (4), and F. Sigmundsson (1)

Rescue excavations at an artefact manufacturing site at Pęgów, Poddębice district, dated to the modern period, have produced several dozens of lumps of flint. The flint exhibits greyish and brownish bands and is macroscopically similar to the well-known banded flint occurring in the area of Krzemionki Opatowskie, Ostrowiec Świętokrzyski district. Artefacts made from this tentatively named 'Pęgów flint' have been identified in archaeological assemblages of different chronological age in the Koło Basin. To verify whether macroscopically similar nodules and artefacts come from the same outcrop and if the artefacts made of banded flint are made of the Krzemionki Opatowskie flint, instrumental neutron activation analysis (INAA) was conducted on samples of Pęgów flint and banded raw material from Krzemionki Opatowskie. Although most of the obtained results fall below INAA detection limits the compostion of chromium content in each sample may reflect common origin of all the analysed pieces from Pęgów. INAA data suggest that the artifacts made of banded flint were mot made from Krzemionki Opatowskie material.

Arranged from oldest to youngest, the main granitic rock units exposed in Khour Abalea are metagabbros, cataclastic rocks, ophiolitic melange, granitic rocks, pegmatite and lamprophyre dykes. The presence of radioactivity associated with the heavy bearing minerals in construction materials-like granite-increased interest in the extraction process. As it turns out, granitic rocks play an important economic part in the examination of an area's surroundings. The radionuclide content is measured by using an NaI (Tl)-detector. In the mineralized pegmatites, U (326 to 2667 ppm), Th (562 to 4010 ppm), RaeU (495 to 1544 ppm) and K (1.38 to 9.12%) ranged considerably with an average of 1700 ppm, 2881.86 ppm, 1171.82 ppm and 5.04%, respectively. Relationships among radioelements clarify that radioactive mineralization in the studied pegmatites is magmatic and hydrothermal. A positive equilibrium condition confirms uranium addition to the studied rocks. This study determined 226 Ra, 232 Th and 40 K activity concentrations in pegmatites samples and assessed the radiological risks associated with these rocks. The activity concentrations of 226 Ra (13,176 ± 4394 Bq kg-1), 232 Th (11,883 ± 5644 Bq kg-1) and 40 K (1573 ± 607 Bq kg-1) in pegmatites samples (P) are greater than the global average. The high activity of the mineralized pegmatite is mainly attributed to the presence of uranium mineral (autunite), uranophane, kasolite and carnotite, thorium minerals (thorite, thorianite and uranothorite) as well as accessories minerals-such as zircon and monazite. To assess the dangerous effects of pegmatites in the studied area, various radiological hazard factors (external, internal hazard indices, radium equivalent activity and annual effective dose) are estimated. The investigated samples almost surpassed the recommended allowable thresholds for all of the environmental factors.

This paper presents a revised geological map at the 1/50,000 scale of the Central Sivas Basin together with a synthetic stratigraphic chart and cross-sections. The map covers an area of approximately 9840 km² within the Eastern Anatolian orogen. The structure of the studied area is dominated by three major tectonic domains: (i) to the south, a north-verging thrust wedge involving Maastrichtian-Eocene sediments deposited onto an ophiolitic basement, (ii) in the center an Oligo-Miocene domain shaped by salt tectonics detached above the thrust wedge, along a late Eocene salt layer, and, (iii) to the north the Pliocene depocenter onlapping onto the Kırşehir basement. The central halokinetic domain exhibits two generations of minibasins (respectively, early Oligocene and late Oligocene to late Miocene), separated by an evaporite canopy. The map includes new stratigraphic correlations for the pre-salt stratigraphy and improve the comprehension of the southern fold-and-thrust-belt.

Roman imperial portraits are commonly recognized and identified by relating specific sculptures to commonly accepted types. The feature that has played a central role in this regard has been hairstyle. Based on the portrayed emperor' s coiffure and facial hair (or lack thereof), scholars have connected portraits to known classifications and prototypes. However, by focusing mainly on hairstyle, this method runs the risk of excluding portraits that do not adhere to the recognized repertoire as possible representations of Roman emperors altogether. Advances in digital art history and computational methods, however, may help solve this problem. By using DCNNbased methods, this article investigates the possibilities of digital identification of Roman imperial portraiture at a quantitative level, without using hairstyle. It demonstrates that there are sufficient visual markers in imperial portraits, aside from hairstyle, that allow facial recognition software to classify portraits when hairstyle is excluded.

Wa nym problemem w stomatologii estetycznej jest wytworzenie materia ów o zbli onym do naturalnego z ba wygl dzie i odpowiednio wysokiej wytrzyma o ci mechanicznej. Materia y takie wykorzystuje si do rekonstrukcji koron Wa nym problemem w stomatologii estetycznej jest wytworzenie materia ów o zbli onym do naturalnego z ba wygl dzie i odpowiednio wysokiej wytrzyma o ci mechanicznej. Materia y takie wykorzystuje si do rekonstrukcji koron z bowych zarówno w formie pojedynczych jednostek, jak i uk adów z o onych (mosty protetyczne). Aktualnie do tego typu rekonstrukcji stosuje si w warunkach klinicznych szk o-ceramik z uk adu podstawowego Li 2 O-SiO 2 (IPS e. max CAD), w przypadku której podstawow faz krystaliczn , w ilo ci do 70% , stanowi dwukrzemian litu Li 2 Si 2 O 5 . Materia rekonstrukcyjny IPS e. max CAD ma barw naturalnych z bów, jest prze wiecalny i charakteryzuje si wytrzyma o ci na zginanie 360-400 MPa. Celem bada by o wytworzenie prze wiecalnej szk o-ceramiki opartej równie na krystalizacji dwukrzemianu litu, ale charakteryzuj cej si podwy szon wytrzyma o ci mechaniczn w stosunku do komercyjnie dost pnych materia ów; takie tworzywa o wysokich parametrach mechanicznych s bardzo przydatne do wytwarzania sta ych protez w formie mostów z o onych z dwóch i wi cej jednostek. Badania ukierunkowano na mody kacj sk adu chemicznego szk a wyj ciowego w taki sposób, aby otrzymane tworzywo szk o-krystaliczne zawiera o podobnie jak IPS e. max CAD dwukrzemian litu jako podstawow faz krystaliczn , przy jednoczesnej poprawie w a ciwo ci mechanicznych, termicznych i chemicznych pozosta ej w tworzywie fazy szklistej. W tym celu do szkie podstawowych wprowadzono wi cej, w stosunku do IPS e. max CAD, takich sk adników jak CaO, Al 2 O 3 i ZrO 2 . W przypadku tworzyw szk o-krystalicznych wzbogaconych w CaO lub Al 2 O 3 nie zaobserwowano istotnych zmian w asno ci w porównaniu z IPS e. max CAD; natomiast wyra n popraw parametrów wytrzyma o ciowych uzyskano w przypadku tworzyw wzbogaconych w ZrO 2 (wytrzyma o na zginanie oko o 470 MPa). Ponadto tworzywo wzbogacone w ZrO 2 charakteryzowa o si bardzo dobra mikrostruktur i wymagan dla tego typu zastosowa prze wiecalno ci . S owa kluczowe: tworzywo szk o-krystaliczne, kierowana krystalizacja szk a, dwukrzemian litu, IPS e. max. CAD An important issue in the dentistry is to produce materials both similar to natural tooth appearance and having high mechanical properties. Presently commercially available materials are used for reconstruction of tooth crowns, both as individual units and complex systems (bridges restorations). For this type of reconstruction the material of glass-ceramic system Li 2 O-SiO 2 base is used, where Li 2 Si 2 O 5 (lithium disilicate) in an amount of up to 70% is the primary crystalline phase. IPS e. max CAD is currently in use as the material for such reconstructions. It has the color of natural teeth: it is translucent and its bending strength is 360-400 MPa. The aim of our research is to produce translucent glass-ceramic also based on the crystallization of Li 2 Si 2 O 5 but with improved mechanical strength when compared to commercially available materials. Such materials with high mechanical properties are very useful for the preparation of permanent implants in the form of bridges consisting of two and more units. Our research was directed to modify the chemical composition of patent glass in such a way that the new material would also contain Li 2 Si 2 O 5 (lithium disilicate) as the primary crystalline phase, but in the same time improving the mechanical, thermal and chemical properties of the remaining glassy phase in the material. For this purpose, the dopes such as CaO, Al 2 O 3 and ZrO 2 were introduced to the chemical composition in amounts bigger than for IPS e. max CAD. In the case of glass-crystalline materials enriched in CaO or Al 2 O 3 there was no signi cant change of properties compared with IPS e. max CAD, while a marked improvement in the strength parameters was obtained for ZrO 2 -rich materials ( exural strength about 470 MPa). In addition, the material enriched in ZrO 2 was characterized with a very good microstructure and translucency required for this type of application.

This article deals with the interpretation of nude portrait statues from the late Republic in Central Italy. These sculptures combine a naked body with a veristic portrait in such a way that irritates the modern observer and has made it difficult for archaeologists to offer a fully convincing interpretation.
Based on a statue from Formia, which belongs to the so-called Formia-Misenum statue type, this paper examines how such statues can be adequately interpreted in their historical context. Starting from the object, the concept of “pictorial evidence” is used to explain in detail how the images could have been understood by a contemporary viewer. The decisive factor is that, contrary to modern viewing habits, one cannot assume a coherence of the manner of depiction and the depicted. Rather, con-temporary viewers of such statues had no problem in understanding the combined messages. In the historical context of the late Republic, statues as the one in Formia can thus be interpreted as the embodiment of complex role models. In an additive manner, they combine characteristics such as physical and military prowess with experience and determination, so that the statues embodied the image of an ideal politician in the context of the late Republic in Central Italy.

In this paper, focused on the Late Cretaceous Serow ophiolite related gabbros from the Torshab area, NW Iran, to enhance our understanding on the tectonic setting of ophiolite formation in terms of pressure-temperature and fluid conditions. The applied methods encompassed field geological observations, petrographic and mineralogical analyses, and whole-rock chemistry assessments. The findings revealed that the calcalkaline gabbros predominantly consist of hornblende gabbro, olivine gabbro, and minerals such as amphibole, ortho-/clinopyroxene, olivine, and plagioclase. According to geochemical signatures such as the depletion of high field strength elements (Hf, Zr, Nb, and Ta) and the enrichment of large ionic lithophile elements (Ba and K) the Serow-Torshab gabbro is considered in relation to an arc setting indicating their origin from a mantle wedge, potentially enriched by subducting crust-derived melts/fluids. The mineral chemical study on mafic phases also suggests a supra-subduction zone (SSZ, fore-arc) environment for the Serow ophiolite, offering valuable insights into the region's geodynamic evolution.

This report describes the synthesis of the coordination compounds indicated, both the experimental procedure and the techniques used for their respective characterization, the analytical methods for the qualitative and quantitative determination of each compound, as well as the infrared characterization Spectroscopy, diffraction of X-ray and Raman Spectroscopy.

The study area is near Goloumak village, 30 km south of Kerman. These rock units consist of acidic rhyolite and dacite, as well as intermediate andesite, basalt, and trachy-andesite. Mafic igneous rocks are alkaline, and intermediate rocks are calc-alkaline to transition range. Volcanic rocks exhibit depletion in Ba, Ti, Nb, and Ta, as well as enrichment in K, Rb, and Th. Basaltic rocks were formed by partial melting of the mantle, based on 87Sr/86Sr and 144Nd/143Nd isotopic ratios. Samples show relative enrichment of 87Sr/86Sr in the mantle array on the Sr-Nd isotope correlation diagram. Mafic rocks are affected by subduction of lithospheric slab or mantle crust metasomatism, as per the comparison of studied samples in the 143Nd/144Nd isotope correlation diagram versus 87Sr/86Sr. Based on Sr-Nd geochronological data, the rocks were formed at 12.5 ±2.0 Ma, corresponding to the Miocene for the basaltic rocks. All samples are in a continental arc margin and post-collision volcanic arc. The magma source is from low to intermediate partial melting of the mantle, as indicated by the LREE/HREE ratio of the mafic and intermediate rocks. LREE enrichment is due to low partial melting of mantle source and magma contamination by crust materials. Basalts show a low melting degree of the mantle for magma formation. Depletion of these rocks of HREE in the source shows garnet in genesis. La and Sm abundance in the studied composition is similar to magma derived from the enriched mantle, comprising about 1-5% of lherzolitic garnet.

The occurrence, storage, and distribution of groundwater in the Precambrian basement complex are influenced by different geological factors. Groundwater is never chemically pure; dissolution of substances takes place in the course of its percolation through the rocks leading to its acquisition of some of their chemical constituents. The purpose of the investigation is to determine the suitability of groundwater for domestic and industrial usage. Four samples were collected from boreholes and six from hand dug wells. Samples were analyzed chemically by using the DR/2010 Spectrophotometer and Digital Titrator while physical parameters where determine using the pH meter, and TDS meter. Hydraulic conductivity and transmissivity results range from 4.24 m/day to 72.63 m/day and 23.84 m 2 /day to 964.0 m 2 /day. The geochemical result obtained from the analysis of 10 water samples in the study area with an average values pH 6.82. Temp. 31 0 C, colour (TCU) 1.00, Turbidity 1.2, Conductivity 174.5𝝁𝒔/𝒄𝒎 , TDS 87.7 mg/l, which revealed that the water physical parameters are below the WHO permissible value. Total Hardness 161.7mg/l, Ca 2+ 64.3mg/l Na + 68.8mg/l, NO3 + 0.1 mg/l Fe 2+ 0.04 mg/l CO3 96.4 mg/l Sulphate 47 mg/l Cl -96 mg/l and F -0.3 mg/l. Results obtained of the water analysis reveals that the concentration of Total Hardness and F - in some parts of the study area are above the permissible standard for drinking water WHO Standard. Therefore, the water in the affected part of the study area should be subjected to proper treatment. The groundwater flow direction is from higher surface elevation to lower surface elevation.

Eruptive activity at Turrialba Volcano (Costa Rica) has escalated significantly since 2014, causing airport and school closures in the capital city of San José. Whether or not new magma is involved in the current unrest seems probable but remains a matter of debate as ash deposits are dominated by hydrothermal material. Here we use high-frequency gas monitoring to track the behavior of the volcano between 2014 and 2015 and to decipher magmatic versus hydrothermal contributions to the eruptions. Pulses of deeply derived CO2-rich gas (CO2/Stotal > 4.5) precede explosive activity, providing a clear precursor to eruptive periods that occurs up to 2 weeks before eruptions, which are accompanied by shallowly derived sulfur-rich magmatic gas emissions. Degassing modeling suggests that the deep magmatic reservoir is ~8-10 km deep, whereas the shallow magmatic gas source is at ~3-5 km. Two cycles of degassing and eruption are observed, each attributed to pulses of magma ascending through ...

Airborne and ground-based differential optical absorption spectroscopy observations have been carried out at the volcano Nyiragongo (Democratic Republic of Congo) to measure SO 2 and bromine monoxide (BrO) in the plume in March 2004 and June 2007, respectively. Additionally filter pack and multicomponent gas analyzer system (Multi-GAS) measurements were carried out in June 2007. Our measurements provide valuable information on the chemical composition of the volcanic plume emitted from the lava lake of Nyiragongo. The main interest of this study has been to investigate for the first time the bromine emission flux of Nyiragongo (a rift volcano) and the BrO formation in its volcanic plume. Measurement data and results from a numerical model of the evolution of BrO in Nyiragongo volcanic plume are compared with earlier studies of the volcanic plume of Etna (Italy). Even though the bromine flux from Nyiragongo (2.6 t/d) is slightly greater than that from Etna (1.9 t/d), the BrO/SO 2 ratio (maximum 7 × 10 À5 ) is smaller than in the plume of Etna (maximum 2.1 × 10 À4 ). A one-dimensional photochemical model to investigate halogen chemistry in the volcanic plumes of Etna and Nyiragongo was initialized using data from Multi-GAS and filter pack measurements. Model runs showed that the differences in the composition of volcanic volatiles led to a smaller fraction of total bromine being present as BrO in the Nyiragongo plume and to a smaller BrO/SO 2 ratio.

The present work examines downwelling radiance spectra measured at the ground during 2013 by a Far Infrared Fourier Transform Spectrometer at Dome C, Antarctica. A tropospheric backscatter and depolarization lidar is also deployed at same site, and a radiosonde system is routinely operative. The measurements allow characterization of the water vapor and clouds infrared properties in Antarctica under all sky conditions. In this paper we specifically discuss cloud detection and the analysis in clear sky condition, required for the discussion of the results obtained in cloudy conditions. First, the paper discusses the procedures adopted for the quality control of spectra acquired automatically. Then it describes the classification procedure used to discriminate spectra measured in clear sky from cloudy conditions. Finally a selection is performed and 66 clear cases, spanning the whole year, are compared to simulations. The computation of layer molecular optical depth is performed with line-by-line techniques and a convolution to simulate the Radiation Explorer in the Far InfraRed-Prototype for Applications and Development (REFIR-PAD) measurements; the downwelling radiance for selected clear cases is computed with a state-of-the-art adding-doubling code. The mean difference over all selected cases between simulated and measured radiance is within experimental error for all the selected microwindows except for the negative residuals found for all microwindows in the range 200 to 400 cm -1 , with largest values around 295.1 cm -1 . The paper discusses possible reasons for the discrepancy and identifies the incorrect magnitude of the water vapor total absorption coefficient as the cause of such large negative radiance bias below 400 cm -1 .

Granites are widely distributed, phaneritic igneous rocks renowned for their high compressive strength and durability, making them a premier choice for dimension stone applications. This study aims to detect and map granitic complexes using geospatial data and spectral algorithms within the arid and semi-arid environment of northwestern Parwan Province, northeastern Afghanistan. Also, to establish an effective and optimized supervised classification approach specifically tailored for identifying granitic complexes in similar terrains. This study utilizes FCC imagery to highlight lithology and employs various machine learning algorithms, including ML, MD, SVM, and SAM, for mapping granitic complexes within the study area. Training and test data were collected from field observations, Google Earth imagery, and geological maps. Our analysis identified two primary granitic complexes within the study area, measuring approximately 19 km × 13 km 2 and 7 km × 3 km 2 , respectively. Ground truth data validation yielded an accuracy of 75%, indicating a positive correlation between the predicted and observed distributions. This enhanced understanding of granite distribution can serve as a valuable guide for future exploration endeavors targeting metallic and non-metallic resources, including aluminum, iron, manganese, rare earth elements, tungsten, etc.

The mantle peridotites of the Hadji-Abad ultramafic complex in Hormozgan province, show some petrological evolutions of the upper mantle of southern Iran. The complex includes harzburgite, lherzolite, dunite and chromitite. Evidences such as different generations of minerals, lobate boundaries between grains, elongation of cr-spinels and pyroxenes, incongruent melting related textures and exsolution lamellae of clinopyroxene in orthopyroxene show that the rocks in this peridotites have past a complex petrological history. The chemical composition of chromites in the Hadji Abad dunites and chromitites is similar to that of boninite melts, while, the mineral chemistry of the harzburgitic and lherzolitic show that the host peridotites belong to the upper mantle and have been depleted from incompatible elements due to 15 to 20 percent partial melting. Geo-thermometric calculations reveal that the studied peridotites equilibriated in upper mantle and spinel-peridotite stability field. Using tectonomagmatic discrimination diagrams shows that the Hadji-Abad ultramafic complex is part of an oceanic lithosphere above suprasubduction zone which has undegone partial melting, high temperature deformations and mantle metasomatism processes associated with this environment. These evidences along with the geological and tectonic setting of the Hadji Abad complex adjacent to the Zagros thrust indicate that the complex probably was created in a suprasubduction zone oceanic mantle section and then tectonically emplaced as part of Esfandagheh-Hadji-Abad mélange in the current situation during the upper Cretaceous. This information confirm the dependence of the Esfandagheh-Hadji-Abad ophiolite mélange on the Neotethyan oceanic lithosphere in southern Iran.

Artykuł przypomina ważny fakt zawarty w jego tytule: To Polak, Ignacy Łukasiewicz, dokonał jako jeden z pierwszych na świecie destylacji ropy naftowej, uzyskał benzynę (która wylewał, bo była zbyt palna) oraz naftę, którą wykorzystał w pierwszej zaprojektowanej przez siebie lampie naftowej. W artykule przypomniano życiorys Łukasiewicza, okoliczności rozpoczęcia aptekarskich eksperymentów z ropą naftową i sukces pierwszych lamp naftowych. Wspomniano też o sukcesach i dramacie pomocnika Łukasiewicza Jana Zeha.

The methodology of the paper is synthesizing information from various research studies on geopolymers and laterite-based geopolymers. The key findings of this paper will be thoroughly examined using all the references cited in the original study. 1. Activator Composition: Optimizing NaOH molarity (12 M) and silicate modulus (SiO₂/Na₂O ratio) to maximize compressive strength. 2. Curing Conditions: Elevated temperatures (80°C) and steam curing accelerate gel formation, reducing porosity and enhancing strength. 3. Precursor Characteristics: Calcining laterite at approx.600°C boosts reactivity, while avoiding sintering. 4. Additives: Incorporating rice husk ash, slag, or fibers (e.g., basalt) improves ductility and thermal insulation. 5. Mechanical Properties: Compressive strength ranges from 14-85 MPa, outperforming traditional cement (20-40 MPa). Flexural strength (3.3-40 MPa) is enhanced by reinforcement materials. 6. Thermal Performance: Low thermal conductivity (0.10-0.77 W/mK) suits insulation applications; foamed variants further reduce energy use in climate control. 7. Durability: Resists freeze-thaw cycles, acids, and chloride/sulfate corrosion, retaining >90% strength after 50 freeze-thaw cycles. The study highlights the potential of laterite-based geopolymers to advance sustainable construction by reducing carbon emissions and resource depletion, which will contributing to global climate mitigation efforts. Their adaptability across various structural applications, coupled with enhanced durability and environmental benefits, made them as a promising alternative for resilient and eco-efficient infrastructure development. 2 Task 2. Summary of references used in the main paper Disclosure: This summary was generated through a combination of AI assisted assessment using ChatGPT and a manual review of each referenced paper to ensure accuracy and reliability in capturing key findings.

The North Coast Schist of Tobago is part of the leading edge of the Caribbean Plate, which has been in oblique collision with northern South America for much of the Cenozoic. The North Coast Schist is dominated by two volcanic "formations" metamorphosed under greenschist-facies conditions during later deformation. The Parlatuvier Formation mostly consists of mafic to intermediate tuffs and tuff breccias with a U-Pb zircon ID-TIMS age of Ma. Trace element data and radiogenic isotopes reveal that the Parlatuvier Formation is derived from 128.66 ‫ע‬ 0.23 a heterogeneous subduction-modified, locally incompatible trace element-enriched, mantle source with some rocks containing the highest 176 Hf/ 177 Hf ratios found in the offshore Caribbean. The Mount Dillon Formation comprises silicified tuffs and tuff breccias that are derived from a more isotopically enriched mantle source with a significant slab fluid-related component. A thin belt of amphibolite-facies dynamothermally metamorphosed metavolcanic rocks lies in contact with a younger island arc pluton. Some of these amphibolites have an isotopically similar source to the Parlatuvier Formation but lack a clear subduction-related component. The age, geochemical heterogeneity, and proximal nature of eruption confirm that the North Coast Schist lay within an east-dipping proto-Greater Antilles arc. We propose that the arc system at the time of North Coast Schist magmatism was actively rifting, possibly during development of a back-arc basin. This arc system shut down during the Cretaceous, making way for southwestdipping Greater Antilles subduction and relative eastward motion of the Caribbean Plate.

Mayo-Belwa Local Government Area has been reported to have deposits of Uranium; hence this study was carried out to measure radionuclide activities in Mayo-Belwa soils and to monitor their potential impact on human health. Soils from a depth of 10 cm were collected from each location, using CANBERA NaI (Tl) detector, the activity concentration of radionuclides of 10 soil samples was measured. The radionuclide concentration ranged between 72.7069-116.8504 Bq.kg-1 for 238 U (measured by 226 Ra activity), 148.9168-981.4994 Bq.kg-1 for 40 K and 22.3332-108.5203 Bq.kg-1 for 232 Th. The gamma absorbed dose rate, annual effective dose rate, ranged between 61.3932-138.1076 nGyh-1 , 0.0830-0.211 mSvy-1 with mean values of 95.1762 ± 21.5257 and 0.1216 ± 0.0359 respectively. The values obtained were compared with the reported data from UNSCEAR, 2000 and ICRP 2005. The excess lifetime cancer risk ranged between 0.00026-0.00061 with an average value of 8.44×10-4. The gamma, internal and external hazard indices ranged between 0.4631-1.0975, 0.5969-0.9978 and 0.3601-0.8087 respectively. However, dose rates recorded in all locations were above the 60 nGyh-1 recommended limits by UNSCEAR 2000. Furthermore, Ganglare had a gamma index above 1, implying a significant radiation hazard. Also, the average excess lifetime cancer risk (ELCR) of 0.844 × 10-3 was relatively high (t < 0.05) and compared to the world average value of 0.29 ×10-3. With the help of this study, we were able to establish the fundamental facts about the levels of radioactivity and related radiological dangers that exist in the soil of Mayo-Belwa Local Government.

Transverse ridges are large topographic anomalies running adjacent to slow-slip oceanic transforms. They form due to different processes, including thermal stresses, hydration-dehydration of peridotites, non-linear viscoelastic rheology of the oceanic crust and vertical tectonic motions of lithospheric slivers induced by changes in ridge/ transform geometry, causing transpression and/or transtension along the transform boundary. A prominent transverse ridge on the southern side of the Vema transform (Central Atlantic) rose probably between 12 and 10 Ma along the entire length (≈320 km) of the transform, exposing a relatively undisturbed section of oceanic lithosphere. We used pelagic limestones encrusting serpentinized peridotites sampled from the lower slopes of the uplifted lithospheric section to date this uplift and define mechanisms of its emplacement. Ages were obtained both by micropaleontology (foraminifera and nannofossils) and by 87 Sr/ 86 Sr isotope ratios. No ages older than ≈12 Ma were obtained, even in samples recovered at sites with crustal ages (determined by magnetic anomalies) well over 12 Ma; on the other side, ages as young as 5.6-8.3 Ma were found in clusters of samples collected from the eastern part of the transverse ridge, probably due to mass-wasting episodes that rejuvenated the substratum. These results support the hypothesis that the Vema Transverse Ridge rose between 12 and 10 Ma due to flexural uplift related to transtension along the transform, in line with a general model whereby transverse ridges rise during discrete events as a consequence of changes in ridge-transform geometry.

The increase in temperature due to global warming is affecting forest ecosystems worldwide. At the treeline ecotone growth is usually restricted by low temperatures. Recently, the impacts of climate change have been visible with the upward shift of the Himalaya fir (Abies spectabilis) in Nepal. Rhododendron campanulatum D. Don grows at the treeline ecotone and subalpine forest. Hardly any studies have been carried on this species in Nepal. The local people have reported that this species has been seen colonizing upper altitude in recent years, however, these needs to be verified with dendroecological studies. The study aims to assess the response of R. campanulatum to climatic variability and to evaluate the relationship of its basal diameter (Groundline) and age using dendroecological methods. Results reveal that the basal diameter was found to be significantly correlated with age (r2= 0.824, p&lt;0.00001). Using the basal diameter age equations, attempts were made to study the age...

This paper is aimed to study the tree line dynamics of Himalayan silver fir (Abies spectabilis D. Don) based on its tree-ring data and age stand distribution at Langtang National Park, Central Nepal. Climatic response on radial growth, recruitment of A. spectabilis and its age distribution are carried out. The average tree density of the species in the study area (total 48 plots of 20 m x 20 m) was 236 no/ha while that for sapling and seedling in the study area was 255 and 350 no/ha, respectively. The stand character and age distribution of the species showed a high level of recruitment in the recent decades, with decreased in average age along with increased altitude. Tree-growth climate relationship showed negative response with temperature of March-May. Upward advancement of tree line is expected in the coming recent decades though not necessarily uniform through the line.DOI: http://dx.doi.org/10.3126/njst.v12i0.6506 Nepal Journal of Science and Technology 12 (2011) 220-229 

In order to improve the understanding of the configuration and breakup history of the Rodinia supercontinent, a paleomagnetic study has been carried out on the 807 ± 12 Ma Aksu dyke swarm (ADS) in Aksu area, northwestern Tarim Block (NW China). The magnetic mineralogical investigations show that the magnetic remanence is principally carried by automorphous titanium-poor magnetite. The measured samples from nine dykes present stable magnetic directions with both normal and reversed magnetic polarities. Because of the monoclinal bedding of overlying sedimentary rocks, no fold test can be provided. However, a positive reversal test is obtained. The magnetic site-mean direction in geographic coordinates is close to, but significantly different from, the present earth field (PEF). A tiltcorrected paleomagnetic pole, therefore, is computed: 19°N, 128°E, DP = 6°, DM = 7° with N = 9. This new paleomagnetic observation reveals that the Tarim Block was located at an intermediate latitude of 43 ± 6°N. Integrating the geochronological studies of dyke swarms from Australia and the Aksu area and referring to the configuration of the Rodinia supercontinent proposed by Moores [Geology 19 (1991) 425] and Li and Powell [Earth Sci. Rev. 53 (2001) 237], the Tarim Block was placed north of Australia with the Aksu dykes being a possible northward continuation of lamprophyre dykes and kimberlite pipes in the northeast part of the Kimberley Craton, Western Australia.

Supergene enriched iron ore deposits in Brazil are typically blanketed by goethite-cemented breccias that form a protective duricrust known as canga. Moderately hard, well consolidated, permeable and resistant to erosion and chemical weathering, the canga blanket protects the relatively friable iron ore below. The protective canga horizons in the Carajás and Quadrilátero Ferrífero mineral provinces represent some of the longest-lived, continuously exposed land surfaces on Earth, and their formation is essential to supergene iron ore enrichment and preservation. Remarkably, the iron-rich duricrusts that have developed in Brazilian tropical rainforest environments, i.e, Carajás, yield geochronological results that indicate that these ancient erosion-resistant surfaces continue to evolve today. Active biogeochemical iron cycling is essential for the 'self-healing' cementation/re-cementation occurring in canga, suggesting that recurrent iron reduction and subsequent oxidation are responsible for canga evolution. Macroscopic biological features in canga including ferruginised plant roots and termite tracks have been linked to the biogeochemical cycling of iron. The 'organic' textures in canga can be traced to the microscopic scale, preserving fossilised bacterial cell envelopes and permineralised biofilms. At the canga surface, naturally rare and endemic rupestrian plant species carve out an existence, commonly in the absence of soil. Growth of grasses also promotes metal cycling highlighting that the rhizosphere contributes to canga evolution. The fossilisation of microbial biofilms and rhizosphere horizons consolidates canga, affecting its permeability, limiting water transport and enhancing biogeochemical cycling. The development of canga has been essential for the formation, preservation, and discovery of iron ore deposits, and its restoration will ultimately be required for mined land remediation of these unique ecosystems. canga; geomicrobiology; iron cycling; biogeochemistry c Elements determined by fused disc (lithium borate fusion) X-ray fluorescence spectroscopy on a PANalytical MagiX FAST, in conjunction with loss-on-ignition at 1000 °C, at Advanced Laboratory Services, Stafford, QLD, Australia. d Al-substituted goethite. 10μm Biogeochemical processes in canga ecosystems: Protection of iron ore and importance in iron duricrust restoration in Brazil Highlights * Canga is a unique iron duricrust that caps and protects supergene enriched iron ores * Geochemical evidence suggests surface processes contribute to ongoing canga evolution * Iron cycling by plants and microbes is likely a significant process in canga * Iron mine restoration will benefit from understanding these biogeochemical processes

We introduce a new method to construct integrated 3‐D models of density, temperature, and compositional variations of the crust and upper mantle based on a combined analysis of gravity, seismic, and tomography data with mineral physics constraints. The new technique is applied to North America. In the first stage, we remove the effect of the crust from the observed gravity field and topography, using a new crustal model (NACr2014). In the second step, the residual mantle gravity field and residual topography are inverted to obtain a 3‐D density model of the upper mantle. The inversion technique accounts for the notion that these fields are controlled by the same factors but in a different way, e.g., depending on depth and horizontal dimension. This enables us to locate the position of principal density anomalies in the upper mantle. Afterward, we estimate the thermal contribution to the density structure by inverting two tomography models for temperature (NA07 and SL2013sv), assumin...

Eruptions at shield volcanoes often occur from radially aligned linear fissures fed by blade‐like magma‐filled cracks (dykes). The fissures of the 2018 Sierra Negra eruption were scattered on the flank of the volcano. Space‐borne radar interferometric data (interferometric synthetic aperture radar) revealed that, unexpectedly, part of the eruption was fed by a 15 km long, tortuous and flat‐lying crack (sill). Here we develop a framework that captures the full three‐dimensional (3D) kinematics of non‐planar intrusions. This includes both an analytical and comprehensive numerical scheme. We constrain the models such that they match the observed ground deformation at Sierra Negra. We show that the peculiar sill trajectory is due to the competing stress gradient magnitudes being close to one another throughout its propagation. By accounting for the interaction of all these factors, these 3D models open the possibility to understand and simulate the geometry of magma transport at volcani...

Research on potentially toxic elements chromium and nickel and laboratory testing of theirconcentrations was carried out in the wider area of Maglaj, with the aim to detect and determine theirquantities, which gave basis for discussion about origins of these pollutants in soil. Field and laboratoryobservations included 45 soil samples, taken by the network, which is dictated by geomorphologicalconditions. The most frequently sampled type of soil are fluvisol and humofluvisol. Concentration ofchromium (Cr) and nickel (Ni) are obtained by the most sophisticated laboratory method (ICP-MS),with a highly sensitive detection threshold (0.1 to 10,000 ppm).Evaluation of test results showed that concentrations of Cr (max. 954 ppm, min 154 ppm, average 457.5pmm) and Ni (max 504.5 ppm, min 103.5 ppm; average 275.57 pmm) are significantly increasedcompared to the concentrations prescribed in the Regulations on determination of allowed amounts ofharmful and hazardous substances in soil (Cr max =...

Seafloor anomalies along mid-ocean ridges with exceptionally thick and compositionally distinct basaltic crust, for example, at Iceland, suggest that the underlying mantle is hotter and chemically different from the adjacent subridge mantle. Here we present hafnium and neodymium isotope ratios of peridotites from the Charlie Gibbs Transform Zone, which is located at the southern end of the Reykjanes Ridge southwest of Iceland. These peridotites are strongly depleted in incompatible elements with extremely high hafnium isotope ratios, suggesting that they had already melted to a large extent before being incorporated into the plume, at least 1 billion years ago, and thereby also became less dense. We argue that seismic velocity anomalies, geodynamic models and geochemical affinities of ridge basalts connect the peridotites from the Charlie Gibbs Transform Zone to the 'Iceland plume'. The thermochemical buoyancy of the moderately hot Iceland plume, but also that of other plumes worldwide, may therefore be strongly influenced by composition. Variable peridotite depletion along the rising Iceland plume could also cause the transient, density-driven pulses in plume flux, which have formed the V-shaped Reykjanes Ridge south of Iceland. Overall, expansion of a ridge-centred plume along adjacent ridges and melting of heterogeneous plume material explains the topographic swell, the seismic anomaly and the formation of V-shaped ridges, as well as the regional distribution of basalts with Icelandic affinity. Abyssal peridotites are mantle rocks from which melt has been extracted during one or more previous melting events, primarily under mid-ocean ridges. Most abyssal peridotites are therefore incompatible element (ICE) depleted, and clinopyroxene (cpx)-poor peridotites or harzburgites (<5 wt% cpx) with high Sm/Nd and Lu/Hf ratios. Over time, such residual peridotites develop extremely high Nd and Hf isotope ratios, much higher than those observed in mid-ocean ridge basalts (MORBs) 1-3. The expected high Hf isotope

Welders undoubtedly experience significant health issues. The question arises: could ionizing radiation from radioactivity be responsible for these health problems, rather than solely attributing them to welding fumes and non-ionizing radiation? This study investigated the activity of primordial radionuclides, including 40 K, 238 U, and 232 Th, and examined the health impacts of exposure to these elements within welding and fabrication environments. Using a gamma spectrometric system consisting of a NaI(Tl) detector, the study revealed significant variations in radioactivity levels such as; 40

Synthesis of sedimentologic, paleocurrent, and organic geochemistry data of the Lower Permian Ga'ara Formation from the Western Desert, western Iraq, shows good hydrocarbon potentiality and deposition by high sinuosity and mixed-load channels, likely by a meandering river system. The Ga'ara Formation includes kaolinitic mudstone beds of various colors and channelized quartzitic sandstone beds. Based on the lithofacies identification, five lithofacies associations have been recognized: channel-floor, point-bar, abandoned channel plug, crevasse splay, and interchannel flood basin. In addition, the paleocurrent analysis and sandstone percentage map indicate a variation of the paleoflow spatially and temporally with a general direction range between NE and Sw, and the depositional environment has been interpreted as a meandering river system. To unravel the hydrocarbon potentiality of the Ga'ara Formation deposits, Pyrolysis and TOC% analyses were conducted on selected samples. The studies indicated that the Ga'ara Formation in western Iraq could be a moderate to excellent rock source. The PCI agrees with TOC content, suggesting that the generation potentiality of the mudstones as a source rock is poor and poor to excellent. All the analyzed samples show that their hydrocarbons are indigenous. The Ga'ara mudstones of the Nijili and West Tayyarah have very good generative potential, whereas the Ubairan samples have excellent generation potentiality. The Nijili and Ubairan samples are at an early stage of oil generation, i.e., immature. In contrast, the Tayyarah sample represents a postmature phase at the end of oil generation. Collectively, these new data on spatial distribution, geologic characters, and organic geochemistry propose that the Ga'ara Formation in western Iraq could be a valuable economic asset with good hydrocarbon potentiality .

Synthesis of sedimentologic, paleocurrent, and organic geochemistry data of the Lower Permian Ga'ara Formation from the Western Desert, western Iraq, shows good hydrocarbon potentiality and deposition by high sinuosity and mixed-load channels, likely by a meandering river system. The Ga'ara Formation includes kaolinitic mudstone beds of various colors and channelized quartzitic sandstone beds. Based on the lithofacies identification, five lithofacies associations have been recognized: channel-floor, point-bar, abandoned channel plug, crevasse splay, and interchannel flood basin. In addition, the paleocurrent analysis and sandstone percentage map indicate a variation of the paleoflow spatially and temporally with a general direction range between NE and Sw, and the depositional environment has been interpreted as a meandering river system. To unravel the hydrocarbon potentiality of the Ga'ara Formation deposits, Pyrolysis and TOC% analyses were conducted on selected samples. The studies indicated that the Ga'ara Formation in western Iraq could be a moderate to excellent rock source. The PCI agrees with TOC content, suggesting that the generation potentiality of the mudstones as a source rock is poor and poor to excellent. All the analyzed samples show that their hydrocarbons are indigenous. The Ga'ara mudstones of the Nijili and West Tayyarah have very good generative potential, whereas the Ubairan samples have excellent generation potentiality. The Nijili and Ubairan samples are at an early stage of oil generation, i.e., immature. In contrast, the Tayyarah sample represents a postmature phase at the end of oil generation. Collectively, these new data on spatial distribution, geologic characters, and organic geochemistry propose that the Ga'ara Formation in western Iraq could be a valuable economic asset with good hydrocarbon potentiality .

In island arcs, the latest stage of subduction-related processes is commonly followed by an extensional tectonic regime. The Stikine terrane of the Canadian Cordillera records one such transition in the rocks of the Early to Middle Jurassic upper Hazelton Group, in northwestern British Columbia. These rocks are host to the world-class Eskay Creek volcanogenic massive sulphide (VMS) deposit. Recent targeted studies of the upper Hazelton Group have documented a number of characteristics which confi rm that the upper Hazelton Group represents a shift from arc building during the Early Jurassic to an extensional environment during the late Early to Middle Jurassic. These characteristics include 1) the presence of original rift bounding faults; 2) unconformities that are associated with rift fi lling conglomerates, including one that grades into more distal facies argillite; 3) a shift in the geochemical signature of mainly intermediate Early Jurassic calc-alkaline volcanic rocks to Midd...

The Hazelton Group comprises the youngest pre-accretionary rocks of the Stikine terrane in NW British Columbia. The group is dominated by several successions of Early to Middle Jurassic subaerial and submarine calc-alkaline island-arc volcanic and sedimentary rocks. One of them, the Salmon River Formation (SRF), which represents a brief period of volcanic activity at the boundary between the Aalenian and Bajocian, is compositionally distinct. The SRF is host to three economic VMS deposits, including the world class Eskay Creek Ag-Au and base metal deposit, as well as over 60 other VMS prospects. The Formation is preserved as several fault-bounded erosional remnants or separate sub-basins along a 200 km belt. The ba-

Rare-earth element abundances of calc-alkaline andesitic rocks from southern Peru ,how that these rocks cannot be produced by a single stage process. The high content of LILE, particularly LREE requires their derivation from a source already enriched in ~hese elements and having a distinctly fractionated REE pattern. It is suggested that ascending hydrous fluids, released from the subducted c~:eanic lithosphere, enriched the upper manHe in LILE by zone refining. The partial melting of such an enriched upper raantle, follo~ed by fractional crystallization, could produce andesitic rocks. REE data indlcetc that shosl-.o-. nitic rocks from southern Peru can be derived from an unfractionated garnet-bearing peridotite by a low degree of partial melting.

The U content of major rock-forming minerals in a suite of calc-alkaline volcamc rocks from Sardinia is very low and their partition coefficient of U (D c =CS/C l') is smaller than 0.1. The values of D U of the mineral phases decrease from basalt to dacite and, in all rocks, the bulk of U and K is present in the groundmass. The apparent close association between K and U in basic and intermediate rocks probably reflects the fact that most of their rock-forming minerals are relatively 'inert' with respect to both of these elements.

The Upper Tertiary to Quaternary volcanic complex of Kouh-e-Shahsavaran in southeastern Iran is composed of calc-alkaline rocks of island arc type (high-alumina basalts, basic andesites, andesites and dacites) even though it was emplaced on the continental basement. The volcanic rocks of the complex are genetically related and were probably derived by low-pressure fractional crystallization of high-A] basalts. The anomalously high content of Sr in some rocks probably reflects an accumulation of plagioclase. The trace element data are consistent with the origin of the parental magma by partial melting of an "enriched" upper mantle peridotite.

The chemical variations in the continental-margin andesitic suite from northwestern Sardinia are compatible with a mechanism involving both fractional crystallization and contamination. Contamination is probably related to interaction with ignimbrites formed by crustal anatexis, which are spatially and temporally associated with andesitic rocks. A similar process may have also affected other calc-alkaline andesitic suites such as those of New Zealand and southern Peru where the contents of lithophile elements and the Sr isotope ratios appear to be related to the composition of associated ignimbrites.

REE abundances in gabbros and peridotites from Site 334 of DSDP Leg 37 show that these rocks are cumulates produced by fractional crystallization of a primitive oceanic tholeiite magma. They may be part of a layered oceanic complex. The REE distributions in the residual liquids left after such a fractionation are similar to those of incompatible element-depleted oceanic tholeiites. The REE data indicate that the basalts which overlie the gabbro-peridorite complex, are not genetically related to plutonic rocks.

The Upper Proterozoic volcanism of northwestern Africa is characterized by the predominance of calc-alkaline rocks. Volcanics with tholeiitic affinities and alkali basalts are rare. The geochemistry and the relative proportions of calc-alkaline rocktypes in the Silet zone (Algeria) and the Ouarzazate formation (Morocco) are similar to those of recent island arc suites where basalts are most abundant while in the Tassendjanet and Gara Akofo zones (Algeria) they resemble contintal margin volcanic suites with a predominance of andesites. The volcanic rocks have undergone low-grade metamorphism which strongly affected alkali and alkali-earth elements and also to a smaller degree, the less mobile elements such as REE, Zr, Hf, Nb, and P. The geochemistry of the calc-alkaline rocks point to a complex origin involving low-pressure fractional crystallization, crustal contamination and derivation from a source already enriched in LILE.

The NW-SE trending mafic dykes intrude the Amgaon gneisses and Dongargarh granite in Wairagarh area of the Western Bastar Craton (WBC). These dykes consist of mainly the clinopyroxene, plagioclase feldspar and minor amphiboles and titano-magnetite. These are metamorphosed to green schist facies. The mafic dykes show tholeiitic trend on multivariate geochemical plots and moderate range of variation in SiO (50.15 to 52.84 wt.%), MgO (5.13 to 7.64 wt.%), Fe O (12.97 to 15.08 wt.%), Al O (12.74 to 14.48 wt.%) and the Mg value ranges from 37.74 to 51.21. Strong positive correlation of Sr, Th, Hf, U, Ga, Ta, Pb, Cs, Rb and HREEs negate the effect of post magmatic alteration. Negative Nb, Ta and Ti with positive Zr and Hf anomalies suggest the effect of assimilation and crustal contamination, which is also supported by Ce/Nb (0.23-0.33) equivalent to the crustal value. Negative ΔNb value suggests depleted mantle source for the mafic dykes of the WBC. Restricted range of (Gd/Yb) (1.05-1.67), (Dy/Yb) (0.94-1.25) and (Sm/Yb) (1.22-2.26) advocate that these mafic dykes were derived from spinel lherzolite source. About 5-15% degrees of partial melting of depleted mantle source is envisaged for the generation of the mafic dykes. The field and geochemical evidences suggest that the mafic dykes of Wairagarh area, WBC were emplaced within continental rift environment.