Volcanic Material Research Articles

THE BABYNSKA SUITE TUFFS OF THE CONTINENTAL FLOOD BASALTS OF WESTERN VOLYN: MINERALOGY, PETROGRAPHY, PETROCHEMISTRY, GENETIC AND APPLIED SIGNIFICANCE

According to the data of comprehensive precision research, the spatial distribution and mineral composition were revealed, the petrographic and petrochemical features, and the genetic and practical significance of the Babynska effusive-pyroclastic suite tuffs of the continental flood basalts of Western Volyn were clarified in connection with the copper content. The thicknesses and hypsometry of the relief of the paleosurface of the pyroclastic formations of the Babynska suite were analyzed and the important elements of its vertical and lateral structure (by area) were clarified, the real picture of which is reflected in the constructed maps of the thicknesses and relief of the paleosurface of the pyroclastic formations of the suite, in particular, on the Ratnе–-Kamin-Kashyrsk Area. The formation of the Babynska suite tuffs in the regime of gravitational deposition of pyroclastic material with the accumulation of tuff deposits at the stage of incomplete solidification of volcanic material and the formation of coarse, non-rhythmic layering, without clear signs of redeposition, i.e. of volcanomictіс origin, has been proven. Differences in the mineral composition and petrochemistry of tuffs of different colors: gray-green and red-brown were found. Emphasis is placed on the enrichment of native copper in tuffs of gray-green color and possible explanations for this correlation are proposed. The obtained results from a genetic point of view provide important information for paleovolcanogenic and paleogeographical reconstructions, in practical terms they contribute to the improvement of the copper bearing prospects of volcanogenic layers of the continental flood basalts and can be proposed for use by production organizations of the geological profile.

Mineralogy and Selenium Speciation Analysis of Early Cambrian Selenium-Rich Black Shale in Southern Shaanxi Province, China

Selenium (Se) is an essential trace element for humans and animals, and an excess of or deficiency in Se is harmful to health. Research on the selenium enrichment zone began in the late 1970s in Shuang’an, Ziyang, southern Shaanxi Province. Naore village is only one selenosis area in Shuang’an, Ziyang, China. Different scholars have conducted systematic studies on the occurrence of selenium, its organic geochemistry and biomarkers, and its content and enrichment patterns in this area. This study applied the TIMA (TESCAN integrated mineral analyzer) for the first time to conduct detailed mineralogical work. The minerals included quartz, carbonate minerals (calcite and dolomite), feldspar (plagioclase, albite, and orthoclase), biotite and muscovite, clay minerals (chlorite and kaolinite), hematite, pyrite, and accessory minerals (almandine, olivine, zircon, and apatite) in Naore village, Ziyang, Shaanxi Province. The ATi index (100 × apatite/(apatite + tourmaline)) is used to determine the source of heavy minerals and the degree of heavy minerals’ weathering. The content POS (100 × (pyroxene + olivine + spinel)/transparent heavy mineral) of olivine, pyroxene, and spinel in heavy minerals can reflect the contribution of basic and ultrabasic rocks in the source area. The ATi and POS indexes for the heavy minerals in the research area were 91.83~99.96 and 0.01~18.75, respectively, reflecting the abundance of volcanic rock material in their source. In addition, the migration, transformation, bioavailability, and toxicity of selenium in the environment are closely related to its species. The species of selenium in various selenium-rich areas (Naore, Wamiao, and Guanquan) mainly include unusable residues and organic forms, followed by humic-acid-bound selenium. The proportions of water-soluble, exchangeable, and carbonate-bound selenium are relatively small, and the proportion of Fe-Mn oxide-bound selenium is the lowest.

Study on the preparation, performance, and mechanism for solid waste cementitious materials

Using granulated blast furnace slag (GGBS) as the volcanic ash material and fly ash (FA) as the supplementary material, the study was conducted to investigate the mix proportions of an alkali-activated solid waste cementitious material under the stimulating effect of alkali activator carbide slag (CS). This type of cementitious material could serve as a substitute for a portion of cement usage, contributing to resource conservation and mitigating environmental pollution caused by solid waste. This facilitates green and sustainable development. Firstly, an analysis of three raw materials was conducted, and the mix proportions were designed with reference to the CaO-Al2O3-SiO2 system of Portland cement. Then 28 groups of specimens were prepared based on the designed mix proportions. The flowability and setting time of each group of specimens were tested. It was observed that an increase in the amount of CS and a decrease in the amount of GGBS resulted in decreased flowability and earlier setting times of the specimens. Additionally, FA exhibited a retarding effect on setting time. Compressive strength tests were conducted on these specimens, revealing that the optimal CS content ranged between 20 % and 40 %. Overall, FA had minimal impact on compressive strength, but it contributed to increased compressive strength in the specimens at later ages. Subsequently, microscopic characterization of the hydration products was performed using X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Differential Thermal Analysis (DTA), Scanning Electron Microscope (SEM), and Energy Dispersive Spectrometer (EDS). The hydration products were identified as predominantly composed of calcium silicate hydrate. The quality and defects in the microstructure of gel products from various specimen formulations were compared to elucidate differences in macroscopic performance. Finally, the hydration process mechanism diagram of alkali-activated materials was presented to illustrate the stimulation and formation of gel products, primarily composed of C-S-H. This diagram revealed the principles behind the action of alkali-activated cementitious materials. The proposed design and testing methodology for the GGBS-FA-CS system in this study had certain reference significance for research in the direction of alkali-activated solid waste cementitious materials.

Compositional Characterization of Glassy Volcanic Material From VSWIR and MIR Spectra Using Partial Least Squares Regression Models

AbstractThe glass phase in volcanic rocks presents a challenge to obtaining compositional data from visible and short‐wave‐infrared (VSWIR) and mid‐infrared (MIR) spectral data of remote surfaces due to its amorphous structure and variable composition. Nonetheless, glass is a common phase in volcanic materials because it forms via the rapid quench of magma and can constitute up to the entirety of a volcanic deposit. Use of partial least squares regression (PLS) to predict glass contents creates models that are insensitive to viewing geometry and sample conditions such as grain size and spectrally inactive compositional variables, enhancing the ability to detect glasses with remote sensing. PLS models are used here to predict crystallinity and oxide composition of samples from VSWIR and MIR spectral data using training spectra from natural volcanic rocks and geologically relevant synthetic samples. Three spectral resolutions of VSWIR and MIR spectra (1, 10, and 100 nm/band, and 1.9, 19, and 190 cm−1/band, respectively) were tested to assess the effects of collection configuration on different spectrometers. PLS models trained on 1 nm and 1.9 cm−1 data sets have the lowest uncertainties of glass modal abundance for VSWIR and MIR, respectively. MIR models predicting sample wt. % SiO2 and FeO, and VSWIR models of wt. % FeO provide accurate estimates (e.g., RMSE‐P of 3.4 wt. % FeO) at all spectral resolutions. Results are based on training data sets skewed to mafic compositions, which affects model accuracies.

Obsidian in the Caribbean islands? Mysterious Ceramic Age glass artefacts in the Lesser Antilles

AbstractThe Caribbean islands witnessed a population expansion of ceramic‐using horticulturalists during the Early Ceramic Age (ca. 500 BC to 750 AD) from the Orinoco Valley to Puerto Rico. We examined 18 lithic artefacts from Guadeloupe and Dominica initially thought to be obsidian, a material believed to be absent from those islands. We investigated the volcanic or meteoritic origin of this unique and yet unknown material through observation (binocular, SEM, microtomography) and geochemical analyses (PIXE, SEM‐EDS, ED‐XRF, EPMA, LA‐ICP‐MS). Elemental analyses rule out the hypothesis of an origin from a meteoritic impact (i.e. identification as tektites). Most of the artefacts have an andesitic composition (<63% SiO2), which appears to be unique among ‘massive’ glasses. The only artefact with a rhyolitic composition has been traced back to the Guadeloupe's Volcan du Tuf, where glassy fragments have been collected and analysed. The geological source of the other vitreous artefacts that exhibit an andesitic composition could be from a sublocal subduction‐arc volcanism (maybe from Martinique), although no volcanic vitreous material of this kind has ever been reported worldwide. These results once again highlight the regional mobility of Early Ceramic populations and the production of standard lithic products using a highly original, albeit low‐quality, local lithic resource, and provide valuable references for future identification of similar materials.

The Nieve volcanic cluster: A Pliocene - Pleistocene lava dome cluster in the Michoacán-Guanajuato volcanic field (México)

The Nieve monogenetic volcanic cluster is located in the central–eastern region of the Michoacán–Guanajuato volcanic field, along the Huiramba fault zone, a relay ramp in the Morelia–Acambay fault system produced by oblique north-northwest transtension. This volcanic cluster includes at least 17 middle Pliocene to late Pleistocene lava domes, two small shield volcanoes, and two scoria cones. Between 4 and 3.8 Ma, two effusive eruptions built two small shield volcanoes overlying one another, with a magma volume of 3.93 km3. Between 2.9 Ma and 21.4 ka, 17 lava domes and two scoria cones were emplaced on the flanks of these volcanoes. The entire cluster resulted in a total erupted volume of 17 km3, covering an area of 326 km2 and reaching a thickness of emplaced volcanic material of 1200 m, resulting in a magma eruption rate equivalent to 0.004 km3/ka. All the rocks associated with this cluster are within a relatively restricted range in composition, between 53.9 and 64.2 wt% SiO₂, from andesite enriched in silica to basaltic andesite. The presence of intrusive-rock xenoliths and xenocrysts with dissolution textures reveals that assimilation processes modified the magmas. Based on the regional geological record, we suggest that the establishment of the Nieve volcanic cluster has been controlled by tectonic structures and the basement of the region, which has allowed the chemical evolution of these magma batches that probably had sources in at least two deep reservoirs as reflected by the Nb/Th versus Ta/U ratio.

Genesis mechanism of laumontite cement and its impact on the reservoir of siliciclastic rock: A case study of Jurassic Shaximiao Formation in central Sichuan Basin, China

Laumontite cement's genesis and impacts on reservoir quality in sedimentary basins have long been studied in sedimentology and petroleum geology. This study aims to analyze the petrological and geochemical properties of laumontite in the Shaximiao Formation, Sichuan Basin, China, and to determine the evolutionary process behind the formation of laumontite. Approximately 175 million years ago, huge volume of volcanic materials filled the Sichuan Basin. During the burial diagenesis phase, the hydrolysis of volcanic particles and alteration of plagioclase provided the necessary ions—Ca2+, Al3+, Si4+, Fe3+—facilitating the formation of laumontite. Simultaneously, the hydrolysis of volcanic substances released ions like Ca2+, Mg2+, and Na+, elevating the PH of pore fluids, and fostering the requisite alkaline conditions for laumontite. Additionally, the dehydration of smectite to illite in nearby mudstones generated Ca2+-rich fluids, migrating into sandstones. The hydrolysis of volcanic particles combined with the Ca2+-rich fluids migrating into sandstones led to the abundant formation of laumontite within temperatures ranging from 60 to 100 °C. During this phase, the formation of laumontite accelerates the densification of the reservoir, leading to a reduction in porosity. In the meso-diagenetic period, organic acids from the underlying formations penetrate the sandstones through fractures, creating secondary pores and dissolution-related grain-edge fractures, significantly enhancing reservoir permeability.

Soils on Recent Tephra of the Somma–Vesuvius Volcanic Complex, Italy

The Somma–Vesuvius volcanic complex emitted huge quantities of volcanic materials over a period from before 18,300 years BP to 1944. The activity during the last period, from post-AD 1631 to 1944, primarily produced lava and pyroclastics via effusive and strombolian eruptions. We investigated the pedogenesis on rocks formed from post-AD 1631 to 1944, occurring on the slopes of Mt. Vesuvius up to Gran Cono Vesuviano and in the northern valley separating Vesuvius from the older Mt. Somma edifice. Pertinent morphological, physical, chemical, and mineralogical (XRD and FT-IR) soil properties were studied. The results indicated the existence of thin and deep stratified soils on lava, as well as the presence of loose detritic covers formed via pyroclastic emplacement and redistribution. The soils showed minimal profile differentiation, frequently with layering recording the episodic addition of sediments. We found that the dominant coarse size of primary mineral particles was preserved, and there was a low level of clay production. The main mineralogical assemblage present in sands also persisted in clays, indicating the physical breaking of the parent material. Chemical weathering produced mineral modifications towards the active forms of Al and Fe and was also attested in selected soils by glass alteration, allophane production, and the presence of analcime in clay as a secondary product from leucite. The differences in glass alteration and analcime production found in the selected soils on lava were related to soil particle size and soil thickness. Concerning the youngest soil present on Gran Cono Vesuviano, other factors, such as the substratum’s age and site elevation, appeared to be implicated.

Magnetic response contrast of Oligo-Miocene basaltic magmatism and structural control during its ascent at the northern tip of the Red Sea Rift

Oligo-Miocene volcanic activity has occurred along the northern Egyptian margin of the Red Sea Rift system, leading to the creation of small-volume monogenetic volcanoes. This research delves into the morphology and setting of these rift-related volcanics by combining aeromagnetic data, remote sensing, and field verification. Basaltic exposures in the study area were mapped using False Color Composite (FCC) and band ratios in Landsat 8 OLI data. In a map view, these mappable volcanic rocks appear as discrete semi-circular basaltic bodies and as discontinuous dikes. The basaltic bodies are aligned along ENE and NW-oriented zones, with most dikes orientated NW-SE. Multiple isolated high magnetic zones with NE and NW orientations were identified. Most basaltic outcrops coincide with high magnetic zones except for Gabal Abu Treifiya along the Cairo-Suez Road. The integration and combination of three layers of surface and subsurface structure patterns reveal an array of variance. The dominant trend of surface and deeper structural lineaments is NW-SE and NE-SW respectively. In contrast, shallow structural lineaments have NW-SE, NE-SW, E-W, and N–S trends. Long linear grabens result from the pairing of NW-SE normal faults. The basaltic occurrences such as Qattamiya and Abu Treifiya are located at the intersection of the NW-SE and E-W normal faults along the NW-SE linear grabens. The field investigation at both locations reveals a polyphase magmatic feeding system manifesting in the surface today as coherent and volcaniclastic rock units. This suggests a diverse range of eruptive styles through a complex feeder system that involves more than one volcanic cone. Though the two areas have good basaltic exposures, yet they have different magnetic responses. The severe alteration of Abu Treifiya's volcanic rocks into nonmagnetic minerals assemblage of zeolite, smectite, calcite, and hydrolysis of basaltic glass diminishes the expected high magnetic anomaly. This study contributes to our knowledge of Rift-related volcanism and the factors influencing the distribution of these volcanic materials.

Salty chemical cocktails as water quality signatures: Longitudinal trends and breakpoints along different U.S. streams

Along urban streams and rivers, various processes, including road salt application, sewage leaks, and weathering of the built environment, contribute to novel chemical cocktails made up of metals, salts, nutrients, and organic matter. In order to track the impacts of urbanization and management strategies on water quality, we conducted longitudinal stream synoptic (LSS) monitoring in nine watersheds in five major metropolitan areas of the U.S. During each LSS monitoring survey, 10–53 sites were sampled along the flowpath of streams as they flowed along rural to urban gradients. Results demonstrated that major ions derived from salts (Ca2+, Mg2+, Na+, and K+) and correlated elements (e.g. Sr2+, N, Cu) formed ‘salty chemical cocktails’ that increased along rural to urban flowpaths. Salty chemical cocktails explained 46.1% of the overall variability in geochemistry among streams and showed distinct typologies, trends, and transitions along flowpaths through metropolitan regions. Multiple linear regression predicted 62.9% of the variance in the salty chemical cocktails using the six following significant drivers (p < 0.05): percent urban land, wastewater treatment plant discharge, mean annual precipitation, percent silicic residual material, percent volcanic material, and percent carbonate residual material. Mean annual precipitation and percent urban area were the most important in the regression, explaining 29.6% and 13.0% of the variance. Different pollution sources (wastewater, road salt, urban runoff) in streams were tracked downstream based on salty chemical cocktails. Streams flowing through stream-floodplain restoration projects and conservation areas with extensive riparian forest buffers did not show longitudinal increases in salty chemical cocktails, suggesting that there could be attenuation via conservation and restoration. Salinization represents a common urban water quality signature and longitudinal patterns of distinct chemical cocktails and ionic mixtures have the potential to track the sources, fate, and transport of different point and nonpoint pollution sources along streams across different regions.

Volcanic and climatic impacts on silicon abundance in shale: Implications for the expansion of Permo-Carboniferous terrestrial plants in North China

Silicon (Si) is known as an important regulator of the global carbon cycle via its effect on silicate weathering in continents and phytoplankton productivity in the oceans. It is also beneficial to plants by improving their resistance to biotic and abiotic stresses. Detailed analysis of geological record of Si in sediments underpins our understanding of ecosystem evolution over geological time. Here, we unravel the mystery of low Si content in Permo-Carboniferous shales from the central North China and link the terrestrial Si fluxes to the thriving forest ecosystems at that time. Provenance fluctuations as indicated by Zr/TiO2 are well explained by episodic volcanic input which are identified by elevated Zr/TiO2 and lowered V/Al2O3 and Cr/Al2O3. CIA and Ga/Rb and K2O/Al2O3 ratios imply cyclic changes of climate in an overall warm and humid condition. The covariation between the volcanic indicators and climatic proxies indicates that the volcanism forced the climate cycles. Despite the felsic sources (high Zr/TiO2 and Th/Sc ratios and low Zr/Sc ratios), the Si-poor shales are universal in Permo-Carboniferous across the North China Block. The enhanced continental weathering of mineral silicates and the hydrolysis of volcanic materials released silica into the environment and led to the eventual deposition of Si-poor shales. The shales lacking in Si tend to have larger TOC contents except for the most distal shales. It implies that the sufficient supply of dissolved-Si in environments may benefit the expansion of terrestrial plants in Permo-Carboniferous and therefore the accumulation of organic matter in the shales. This work provides new insight into feedback linking volcanism, climates, terrestrial dissolved silica flux, and terrestrial ecosystems in Permo-Carboniferous North China Block.

GEOCHEMICAL CHARACTERISTICS OF MAFIC ROCKS IN THE STRUCTURE OF THE YENISEI-KHATANGA TROUGH AND THEIR BELONGING TO THE SIBERIAN TRAP PROVINCE

Consideration is being given to the geochemical composition of the rocks, representing the hidden part of the volcanic and intrusive material in the structure of the Yenisei-Khatanga Trough (YKT), in relation to its belonging to a large igneous province (LIP) of Siberia. The geochemical characteristics of mafic rocks, presenting in the sedimentary complexes of the YKT, correspond to three types of mafic rocks allocated to the Siberian LIP: Nadezhdinsky (low Ti), Morongovsky (low Ti), and, in limited quantities, Ivakinsky (rift-related high Ti). Based on the seismic data, there was constructed a deep structural-tectonic cross-sectional model, and there was considered the position of mafic intrusions in the sedimentary section in the western junction zone of the Siberian Platform and the Kara (Taimyr-Severozemelsky) orogen. The seismic data show an anomalous area in the lower crust and at the crust–mantle boundary immediately below the YKT depocenter, whose seismic section is characterized by a chaotic scattered wave field with no reflective boundaries.

μ-Raman spectroscopy as a useful tool for improving knowledge of ancient ceramic manufacturing technologies

In recent decades, μ-Raman spectroscopy has become a powerful technique for studying ceramics, with the advantage of performing fast, reproducible and reliable analyses that provide effective information on ceramic technology. In the present paper, the potential of μ-Raman spectroscopy was evaluated by comparing the results of spectroscopic analyses with a wide range of conventional compositional and mineralogical analyses. Particular fragments of pottery from the archaeological site of Pollena Trocchia (Campania, Italy), characterized by a variegated color zonation, a symptom of uncontrolled firing conditions, were subjected to in-depth analytical investigation. Data from the μ-Raman measurements were in very good agreement with the analytical set of conventional analyses and permitted to better constrain the firing temperatures, evaluate changes in the oxidative steps, and assert the provenance of volcanic raw materials. The results illuminated that pottery was crafted by mixing a low-CaO base clay with volcanic temper from the environs of Vesuvius and fired in a not well-controlled firing atmosphere, which determined the development of Fe(III) oxides at rims of sherds and Fe(II)-bearing phases at cores. Moreover, even in the absence of newly-formed minerals, firing temperatures were estimated between 900 and 950 °C, as suggested by the mineralogical and spectroscopic evidence of the prograde 10 Å dehydroxylated phyllosilicates.

Chemistry Contribution to Stratospheric Ozone Depletion After the Unprecedented Water‐Rich Hunga Tonga Eruption

AbstractFollowing the Hunga Tonga–Hunga Ha'apai (HTHH) eruption in January 2022, stratospheric ozone depletion was observed at Southern Hemisphere mid‐latitudes and over Antarctica during the 2022 austral wintertime and springtime, respectively. The eruption injected sulfur dioxide and unprecedented amounts of water vapor into the stratosphere. This work examines the chemistry contribution of the volcanic materials to ozone depletion using chemistry‐climate model simulations with nudged meteorology. Simulated 2022 ozone and nitrogen oxide (NOx = NO + NO2) anomalies show good agreement with satellite observations. We find that chemistry yields up to 4% ozone destruction at mid‐latitudes near ∼70 hPa in August and up to 20% ozone destruction over Antarctica near ∼80 hPa in October. Most of the ozone depletion is attributed to internal variability and dynamical changes forced by the eruption. Both the modeling and observations show a significant NOx reduction associated with the HTHH aerosol plume, indicating enhanced dinitrogen pentoxide hydrolysis on sulfate aerosol.

Contribution of Asian dust into the sediment budget of the Parece Vela Basin over the last 1 Ma: Implications for the climate change in East Asia

By quantifying the deposition of Asia-derived dust in the Western Pacific Ocean it is possible to constrain the consequences of climate change in East Asia. However, the rates of eolian dust deposition and its transport mechanism in the low-latitude Pacific remain uncertain. Core CP19 recovered sediment dating from ∼1 Ma to the present in the Parece Vela Basin (PVB). In this study we present bulk-rock major and trace element geochemistry, and Sr and Nd isotopic compositions from this sediment. The results reveal that these clastic sediments are a mixture of volcanic materials derived from the adjacent island arcs and eolian dust material originating from the arid regions of East Asia. Within the PVB, the proportion of Asian dust in the detrital sediment ranges from 30% to 50%, with an average of 44%. The majority of the dust originated from Eastern Asian deserts. Sr and Nd isotopes indicate that there is a significant increase in the overall proportion of eolian dust in the PVB starting at ∼0.64 Ma, influenced by an enhanced East Asian winter monsoon. In contrast, strengthening of the East Asian summer monsoon led to a decrease in the proportion of the eolian dust from the Ordos deserts. The notable alteration in eolian dust flux to the PVB corresponds to an abrupt intensification of aridity and monsoon climate in the East Asian continent at ∼0.64 Ma, caused by the Middle Pleistocene Climate Transition.

Improving the Performance of Porous Concrete by Utilizing the Pumice Aggregate

The performance of porous concrete, widely used for storm-water management, can be compromised due to the limitations of conventional aggregates. This research investigates the potential of pumice aggregate, a lightweight volcanic material, to enhance the mechanical strength, durability, and permeability of porous concrete. A series of experimental tests were conducted to evaluate the effects of varying pumice aggregate content on the properties of porous concrete. The results demonstrate that the inclusion of pumice aggregate significantly improves the compressive strength, flexural strength, and freeze-thaw resistance of porous concrete. Moreover, the permeability of the concrete mixtures is enhanced, allowing for better storm-water infiltration. The favorable porous characteristics of pumice aggregate contribute to increased void content within the concrete, enhancing its water storage capacity and reducing runoff. These findings suggest that utilizing pumice aggregate can lead to the development of more sustainable and efficient porous concrete systems for storm-water management. The incorporation of pumice aggregate not only improves the mechanical and hydraulic performance of porous concrete but also offers environmental benefits by utilizing a lightweight and natural material. The findings of this research have significant implications for sustainable construction practices and the effective management of storm-water runoff.

Pyroclastic component influence on the weathering indices assessment in marine sediments – Lessons from Upper Ordovician of the Baltic Basin

The chemical weathering indices of the sediments can serve as tools for estimating the intensity of weathering in the sediment source rock area and its changes in response to the dynamic interplay of climate, tectonics, and bioevolution. The siliciclastic terrigenous component, comprising sediment particles formed during weathering, carries information regarding weathering. Nevertheless, the presence of volcanic material with silicate composition in the sedimentary record can introduce bias to the weathering estimate by incorporating pyroclastic material that has not undergone weathering but is susceptible to diagenetic alteration. Therefore, a comprehensive understanding of the nature and significance of the volcanic component in sediments is imperative for accurately interpreting weathering derived from sedimentary successions. Our study focuses on investigating the presence of the volcanic component and its influence on weathering indices calculation in the Upper Ordovician sedimentary succession of the Baltic Basin. The results from geochemical massbalance mixing modelling reveal that volcanic material is not confined solely to discrete altered volcanic ash beds (bentonites), and a substantial amount of volcanic material is dispersed or re-deposited into the host rock. Within the interval containing discrete bentonite beds, the volcanic component in the carbonate host rock sections ranges from 50% to 90%, and significantly impacts the terrigenous fraction weathering index calculations. This underscores the necessity of considering the nature and significance of the volcanic component when interpreting geochemical-mineralogical signals.

Disaster Management for Geopark-Based Tourism in Yogyakarta, Indonesia

Yogyakarta in Indonesia is on the south flank of the Merapi Volcano and is bordered by the Southern Mountain, West Progo Mountain, and the Indian Ocean. Many geological and archaeological phenomena are found here, making geological and cultural diversity part of the wealth of Yogyakarta. One of these was Hindu-Buddhis temples developed during the 8th-10th century that were buried by volcanic materials dated between 1910 y BP and 2010 AD and resulted in cracks, wavy paleosols, liquefactions, and bumpy buildings. The catastrophe eruption of 4 VEI in October 2010 and the earthquake with 6,2R on May 27th, 2006, took thousands of lives. Apart from the disastrous effects, the natural disasters built unique geodiversity with education and utilization potentials. Using the values of education, conservation, early warning, utilization, uniqueness, and the improvements of the economic community developments, 15 geoheritages have been appointed, to be an Aspiring Jogja Geopark. This paper aimed to assess qualitatively and quantitatively whether the geological, biological, and cultural diversities can be prepared. The method used was questionnaires filled by visitors, local people, academicians, local tourist managers, small and medium enterprises (UMK), and micro small and medium enterprises (UMKM). The data was processed using RapidMiner software for clustering. The results discovered that people around the 15 destinations did not know about the Aspiring Jogja Geopark, but the academicians, local governments, POKDARWIS (local tourist managers), and the UMK and UMKM knew. Because of their limited knowledge, the local people were unaware of the park. However, they were surprised and enthusiastic about the geopark. Visitors very happy and proud of it. The community had been waiting for a geopark. It is a symbol of the unity of Yogyakarta’s people and the ruler, an embodiment of the slogan of “life in harmony with disasters”, and the optimisation of the geoheritage’s utilization to improve the local economy.&#x0D; Keywords: disaster management, geopark tourism, Yogyakarta

Fabrication and Mechanical Evaluation of Eco-Friendly Geopolymeric Mortars Derived from Ignimbrite and Demolition Waste from the Construction Industry in Peru

Ignimbrite rock is a volcanic material located in the Arequipa region (Peru), and for centuries, it has been used as a construction material, giving a characteristic light pastel, white to pink color to the city of Arequipa, with white being the most common. In the present study, the potential use of three types of Arequipa raw materials (ignimbrite rock powder, calcined clay powder, and demolition mortar powder) as the main source of new binders or the manufacture of environmentally friendly mortars, without the addition of ordinary Portland cement (OPC) is discussed. In this work, an in-depth characterization of the materials used was carried out. The proposed fabrication route for geopolymeric materials was considered for the manufacture of binders and mortars using an alkaline solution of NaOH with values between 12 and 18 molar, as a trigger for the geopolymerization process. Geopolymeric mortars were obtained by adding a controlled amount of fine sand to the previously prepared mixture of binder raw material and an alkaline solution. Conventional OPC and geopolymeric mortars manufactured under the same conditions were mechanically evaluated by uniaxial compression tests at a constant compression rate of 0.05 mm/min and under normal conditions of temperature and atmosphere, where the most optimal values were obtained for 15 molar alkaline solutions of ignimbrite without the addition of aggregates, with values of compressive strength of 42 MPa and a modulus elastic of 30 GPa. The results revealed a significant increase in the maximum strength and modulus of elasticity values when the volumetric fractions of OPC are completely replaced with geopolymeric binders in the study conditions of this work, demonstrating the enormous potential of the ignimbrite rock and construction waste studied, as raw material of alternative mortar binders without the addition of OPC. With this work, the ignimbrite rock, of great value in the region and also found in other areas of the Earth’s geography, was characterized and valued, in addition to the calcined clay and demolition mortar of the region.

Architecture and sedimentary evolution of the Ladinian Kobilji curek basin (External Dinarides, central Slovenia)

The study area is located in cental Slovenia, and geologically located at the junction between the Alps and the Dinarides. The Middle Triassic of this region is characterised by intense rifting manifested by differential subsidence and volcanism. This led to a major paleogeographic reorganisation of the region, where three paleogeographic domains formed in the Upper Triassic: The Julian Carbonate Platform in the north, the intermediate Slovenian Basin, both parts of the Southern Alps, and the Dinaric (Adriatic, Friuli) Carbonate Platform in the south, which today is a part of the External Dinarides that host the area of investigation. Prior to the installation of the Dinaric Carbonate Platfrom, i.e. in the Ladinian, the entire area of the preset-day External Dinarides broke up into numerous tectonic blocks that were exposed to either erosion or continental, shallow-marine, and deep-marine sedimentation. In this study, we analyse at small scale a complex transitional area between a local carbonate platform and the Kobilji curek basin (depositional area dominated by deeper marine sediments), located in the Rute Plateau in central Slovenia south of Ljubljana. During enhanced subsidence, the basin was filled with volcanic material (tuffs and volcanogenic clays and subordinate extrusive material), while the adjacent platform aggraded. The slope was positioned above active paleofaults. During relative sea level lowstand, the platform prograded across the basin. The study area is divided into four major tectonic paleoblocks. The NW paleoblock experienced the most enhanced subsidence, and the platform prograded twice in this area and was submerged again by the rejuvenated subsidence and/or sea-level rise. The second and third paleoblocks subsided only during discrete major subsidence events, and the carbonates of the platform and slope were soon reinstated therein. In the fourth paleoblock to the east the platform persisted during the Ladinian. In the Carnian, the entire study area became emerged, and continental clastics were deposited. These were then replaced by a uniform shallow marine/intertidal Hauptdolomit (Dolomia Principale) formation at the onset of the Norian. This study provides the first detailed reconstruction of the sedimentary evolution of small-scale Ladinian basin and platforms system in the northern External Dinarides.