Eruptive Processes Research Articles

Geology, Archaeology, and Historical Studies of the Late 16th Century Plinian Eruption of Raung Volcano: A Potential Case for Disaster Geotourism in Ijen UNESCO Global Geopark, East Java, Indonesia

The enigmatic major eruption in the late 16th century, believed to have originated from Raung, the most active stratovolcano in the Ijen UNESCO Global Geopark in East Java, Indonesia, has ignited significant debate among researchers and historians due to its profound impact on the region. This research aims to substantiate Raung as the likely source of the major eruption by integrating geological, archaeological, and historical data. This study synthesizes current findings and explores ongoing debates surrounding historical volcanic activities. Eruption parameters suggest that the late 16th century eruption exhibited a Plinian type, characterized by an explosive eruption column reaching the stratosphere, widespread pumiceous tephra fallout, and pyroclastic density current (PDC). Stratigraphic succession reveals that the eruption occurred in five phases, with deposits from 10 eruptive units. These deposits are mainly concentrated on the northwestern flank of Raung. Archaeological findings, historical records, and local legends converge to pinpoint the occurrence of this catastrophic event in the late 16th century. These diverse sources estimate that the eruption resulted in approximately 10,000 casualties, marking it as one of the most significant volcanic disasters in the past 500 years. The implications of this eruption extend beyond historical documentation, providing a critical case study for advancing disaster mitigation strategies through geotourism in the geopark area. Moreover, the eruption record outcrops identified in this study can be proposed as potential new geosites within the Ijen UNESCO Global Geopark, enhancing its educational and touristic value. We propose the Jebung Kidul, Alas Sumur, and Batu Sappar sites as potential disaster-based geosites, considering that these sites record the eruption process and preserve archaeological structures. This addition would not only commemorate the historical event but also promote awareness and preparedness for future volcanic activities in the region.

Explosive eruption processes inferred from high-frequency seismic waveforms of eruption tremor and explosion events

Summary We investigated the relation between high-frequency seismic signals and eruption size and duration using seismic data of eruption tremor and explosion events generated during sub-Plinian and Vulcanian eruptions, respectively, at various volcanoes. We estimated source amplitude functions from seismic envelope seismograms in the 5−10 Hz band, in which S-waves are assumed to radiate isotropically. Because seismic data associated with explosive eruptions can be contaminated by infrasound signals, we confirmed that contamination did not significantly affect the source amplitude functions quantified from our analysed waveforms. We approximated the source amplitude functions of eruption tremor and explosion events by quadrilateral and triangular shapes. For eruption tremor, the durations of the source amplitude functions increased with decreasing slope of the initial phase, i.e. between onset and maximum amplitude. For explosion events, both the maximum and cumulative amplitudes of the source amplitude functions increased with increasing slope of the initial phase, but the overall durations clustered around a typical value. Moreover, the initial phase durations of eruption tremor were longer than those of explosion events. Based on eruption models proposed by previous studies, Vulcanian and sub-Plinian eruptions have been thought to be triggered by accumulation of magma at a shallow part in a conduit and mixing of cool mushy magma with hot fresh magma in a reservoir, respectively. The above differences between the source amplitude functions of eruption tremor and explosion events can be explained by the distinct eruption triggering processes of sub-Plinian and Vulcanian eruptions. Our results suggest that source amplitude functions are useful for investigating eruption processes and estimating eruption sizes and durations for seismic eruption monitoring.

The Role of Autophagy on Osteogenesis of Dental Follicle Cells Under Inflammatory Microenvironment.

This study investigated the role of autophagy on osteogenesis of DFCs under inflammatory microenvironment during tooth eruption. DFCs were isolated and identified. Lipopolysaccharide (LPS) was used to construct the inflammatory microenvironment invitro and invivo. Cell viability was examined by CCK-8 assay. Osteogenic differentiation was evaluated by alkaline phosphatase (ALP) staining, alizarin red S (ARS) staining. The gene and protein levels were examined using qRT-PCR and western blot analysis, respectively. We observed the process of tooth eruption after local LPS injection by micro-CT and HE staining. Osteogenesis and autophagy were monitored through qRT-PCR, western blot and histological staining of specific markers. LPS at the indicated concentrations did not produce toxic effects on DFCs, and significantly promoted the inflammatory gene expression. LPS inhibited osteogenic differentiation and activated autophagy in DFCs. Blocking autophagy with 3-MA reversed the expression of osteogenic markers in LPS-treated DFCs. Additionally, the eruption of LPS-treated teeth was accelerated and their DFs exhibited an increased expression of TNF-α and Beclin1, and decreased expression of ALP and RUNX2. Autophagy was involved in the suppression of the DFCs osteogenesis in an LPS-induced inflammatory condition, suggesting the pivotal role of autophagy in inflammation-induced premature tooth eruption.

Comparative Analysis of Electric and Conventional Vehicles Performance in the Evacuation Process of Mount Semeru Eruption Victims Based on Geographic Information Systems

The Lumajang Regency is highly vulnerable to various natural disasters, particularly the potential eruption of Mount Semeru. In disaster response efforts, the local government needs to prepare effective and efficient evacuation routes, taking into account the magnitude of the eruption impact in the Semeru disaster-prone area. This research focuses on evacuating vulnerable residents using electric and conventional vehicles. This study is categorized as a vehicle routing problem with energy constraint (VRPEC) because the electric vehicles utilized in this research do not require recharging during their operational process, ensuring rapid evacuation as it is essential. By utilizing Geographic Information Systems (GIS)-based optimization, the best route to evacuate all victims within 12 h is determined. This study involves developing scenarios considering the number of vehicles and their travel distances. There are also evacuation guidelines, including the implementation of priority points and evacuation zone usage. The research results indicate that scenarios EV 5, 8, and 10 are the most optimal for using electric vehicles. Meanwhile, the optimal scenario for conventional vehicles is scenario 5. This analysis shows that implementing electric vehicle scenarios is superior to conventional vehicle scenarios in terms of the total time required to evacuate all victims.

Investigating 10 Yr of Volcanoacoustic Activity at Tungurahua Volcano, Ecuador, Aided by Machine Learning

Abstract Here, we present the results of applying diverse data processing and machine learning tools to investigate a very large dataset obtained from single station infrasonic recordings from the last 10 yr of the most recent period of explosive activity at Tungurahua volcano, Ecuador. To increase the quality and quantity of information extracted from the large data set and enhance pattern recognition, we combined traditional techniques with more recent ones. We divided the investigation into sequential steps: detection, discrimination, cleaning, and clustering. For the detection step, we tested the classical short-term average/long-term average algorithm and an algorithm specific for explosions detection called “Volcanic INfrasound Explosions Detector Algorithm (VINEDA)” and detected 118,516 events. To clean the detected signals from potential false positives, we used supervised classification that reduced the events to 75,483, and a catalog cleaning procedure using shallow learners including support vector machines, random forests, and a single layer neural network, trained using data from a manual catalog, to a final number of 36,359 events. This led to a sixfold increase in detected explosions compared to the manual catalog. Then, we applied hierarchical clustering to a well-studied time window of activity using two independent difference metrics: dynamic time warping and waveform cross correlation and showed the insights and drawbacks from this approach. We showed that the different techniques were able to reveal repeating and striving events between selected different eruptive phases and associated them to possible changes in eruptive dynamics. Finally, to analyze the whole dataset at once we used a convolutional autoencoder network and obtained similar results to the classical clustering in a fraction of the time. We identified different families of explosions that appeared, sometimes intermittently, and revealed various potentially competing eruptive processes during the whole time period.

Volcanomagnetic signals related to the 2021 Tajogaite volcanic eruption in the Cumbre Vieja rift (La Palma, Canary Islands)

After almost 50 years of quiescence, the Cumbre Vieja rift in La Palma underwent a reactivation process that culminated in the eruption of the Tajogaite volcano from September 19 to December 13, 2021. In July 2021, a magnetic station (CFU) was deployed in the western flank of the Cumbre Vieja rift, 2 km away from the site where the eruptive vents would open two months later. In September 2021, a second magnetic station (SAN) was installed near the southern end of the rift. In this paper we study two months of geomagnetic data at CFU before the eruption and three months of geomagnetic data at SAN during the eruption. The analysis of these time series revealed a magnetic signal at the CFU station with an amplitude of 10 nT and a duration of 10 days by mid-August, one month before the eruption onset. We studied possible correlations with other physical parameters (ground deformation, long-period and very-long-period seismic activity) and concluded that this signal could be related to changes in the magnetization of rocks beneath the volcanic edifice caused by magma intrusion and volcanic/hydrothermal fluids circulation preceding the eruption. At the SAN magnetic station, the time series suggests that a slight decrease in the geomagnetic field could reflect the end of the eruptive process.

A fast-filament eruption observed in the Hα spectral line

Context. Solar filament eruptions usually appear to occur in association with the sudden explosive release of magnetic energy accumulated in long-lived arched magnetic structures. The released energy occasionally drives fast-filament eruptions that can be the source regions of coronal mass ejections. A quantitative analysis of high-speed filament eruptions is thus essential to help elucidate the formation and early acceleration of coronal mass ejections. Aims. The goal of this paper is to investigate the dynamic processes of a fast-filament eruption by using unprecedented high-resolution full-disk Hα imaging spectroscopy observations. Methods. The whole process of the eruption was captured in a wide spectral window of the Hα line (±9.0 Å), which allowed for the detection of highly Doppler-shifted plasma. By applying the “cloud model” and obtaining two-dimensional optical thickness spectra, we derived the Doppler velocity; the true eruption profiles (height, velocity, and acceleration); and the trajectory of the filament eruption in 3D space. Results. The Doppler velocity maps show that the filament was predominantly blueshifted. During the main and final process of the eruption, strongly blueshifted materials manifest, traveling with velocities exceeding 250 km s−1. The spectral analysis further revealed that the erupting filament is made of multiple components, some of which were Doppler-shifted approximately to −300 km s−1. We found that the filament eruption attains a maximum true velocity and acceleration of about 600 km s−1 and 2.5 km s−2, respectively, and its propagation direction deviates from the radial direction. On the other hand, downflows manifested as redshifted plasma close to the footpoints of the erupting filament move with velocities of 45–125 km s−1. We interpret these redshifted signatures as draining material and therefore as mass loss of the filament, which has implications for the dynamic and the acceleration process of the eruption. Furthermore, we have estimated the total mass of the Hα filament, resulting in ∼5.4 × 1015 g.

A coupled atmosphere-ocean source mechanism was a predictor of the 2022 Tonga volcanic tsunami

Volcanic tsunamis pose significant threats to nearby coastal communities. Despite extensive research, the mechanism behind tsunami generation remains unclear, and the ability to forecast a destructive tsunami has proven elusive. Here we present findings from the 2022 Tonga volcanic incident, showing that the leading air-pressure wave holds promise as a key predictor of tsunami behavior. We constructed an integrated atmosphere-ocean model to explain the underlying mechanism and validated it with various data, including satellite altimetry measurements. Contrary to prior hypotheses, our results reveal that: (1) the eruption process governs both the air-pressure and tsunami dynamics; and (2) the resulting crater volume controls the volcanic ejecta that produces the air-pressure waves, while the corresponding mass loss in the ocean triggers influxes of water into the crater, generating the tsunami. This study unveils a coupled atmosphere-ocean source mechanism in generating volcanic tsunamis and advocates for incorporating air-pressure sensors into early warning systems.

Tooth Eruption Disorders: Literature Review and Clinical Case Reports

Introduction and purpose: Tooth eruption disorders are complex issues that can affect both primary and permanent teeth. The process of tooth eruption is a natural stage of development, but it can sometimes be disrupted. Common eruption disorders include delayed eruption, tooth impaction, premature eruption, and abnormalities in the location and direction of eruption. In each case, consultation with a specialist is required, along with early diagnosis and subsequent planning of appropriate treatment. State of knowledge: Impacted teeth are a common occurrence in dentistry and they occur in 0.8–3.6% of the general population The most frequently impacted teeth, in decreasing order of prevalence, are third molars, maxillary canines, mandibular premolars, and maxillary central incisors. Factors contributing to tooth impaction can be general, local, or genetic. Impacted teeth and difficulties with eruption may be associated with complications such as follicular cysts and a variant of these cysts known as eruption cysts. Summary: Tooth eruption disorders require an individualized diagnostic and therapeutic approach. Depending on the issue, treatment may involve observation, orthodontic interventions, and in some cases, surgical procedures. Early diagnosis and appropriate treatment are crucial to prevent complications such as malocclusion, damage to adjacent teeth, or unsatisfactory aesthetics. Radiographs can help confirm the presence of impacted teeth or in some cases, CBCT may be used for more detailed imaging.

Splitting and Eruption of an Active Region Filament Caused by Magnetic Reconnection

To gain a deeper understanding of the intricate process of filament eruption, we present a case study of a filament splitting and erupting by using multiwavelength data of the Solar Dynamics Observatory. It is found that the magnetic reconnection between the filament and the surrounding magnetic loops resulted in the formation of two new filaments, which erupted successively. The observational evidence of magnetic reconnection, such as the obvious brightening at the junction of two different magnetic structures, the appearance of a bidirectional jet, and subsequent filament splitting, were clearly observed. Even though the two newly formed filaments experienced failed eruptions, three obvious dimmings were observed at the footpoints of the filaments during their eruptions. Based on these observations, it is suggested that magnetic reconnection is the trigger mechanism for the splitting of the original filament and the subsequent eruption of the newly formed filaments. Furthermore, the process of filament splitting dominated by magnetic reconnection can shed light on the explanation of double-decker filament formation.

Estimation and uncertainty quantification of magma interaction times using statistical emulation

The evolution of volcanic plumbing systems, which controls the style and size of eruptions, is largely determined by processes at depths that are not observable. Scientists use numerical models to simulate these processes and compare the outputs with data on erupted products to understand the plumbing system and eruption processes. However, our ability to explore the parameter space in order to match petrological and geophysical observations is limited by the computational cost required for such simulations. As an alternative, we present a statistical emulator that can reproduce the numerical results as a function of a set of input parameters. This approach can be used to invert the observed distribution of whole rock chemistry to determine the duration of interaction between magmas preceding an eruption and identify the best matching input parameters. This method intrinsically includes error propagation, thus providing reliable confidence intervals for the relevant parameters of the numerical simulations.

The color systematics of volcanic ashfall samples in estimating eruption sequences: a case study of the 2017–2018 eruption at Shinmoe-dake, Kirishima volcano, Southwest Japan

The color of pyroclasts is fundamental, because it reflects various magma properties and eruption processes, including particle morphology, chemistry, and petrological characteristics. However, deriving the componentry ratio (CR) of pyroclasts for ongoing eruption monitoring remains challenging due to the lack of a robust quantitative standard. The derivation of the CR, as well as other petrological analyses, is too laborious and time-consuming to introduce as a sustainable monitoring method. To address this, we employed spectroscopic colorimetry to rapidly and quantitatively describe eruptive product colors, enabling CR derivation based on clear, objective standards for ash particle classification. Through color spectroscopy of bulk and sieved ash samples, we analyzed the major size fraction for time-series samples during the waxing stage of the 2017–2018 Shinmoe-dake eruption in Kirishima volcano, Southwest Japan. Our findings reveal that the color changes in bulk ash systematically changed with the evolution of componentry. This temporal color change was due to an increase in the amount of vesicular particles with clear glass against dark angular lava particles, as well as a grain size change, which we interpret as an indication of a transition from phreatic/phreatomagmatic to magmatic eruption. Subsequently, the color of the ash changed when the amount of different lava particles increased gradually, coinciding with a shift toward a more dominant effusion of lava. As the lava effusion continued, a slight reddening of the ash, indiscernible to the naked eye, was clearly detected by the spectrometer before the onset of intermittent Vulcanian eruptions. We interpreted this reddening as oxidation resulting from decreased ascent speed and caprock formation, which accumulates overpressure for Vulcanian explosions. These results highlight the potential of rapid, objective color value and componentry derivation for sustainable quasi-real-time monitoring of ongoing eruption materials.Graphical

Research on thermal runaway characteristics and mechanism of NCM811 Lithium-ion batteries under cross-seasonal and wide-temperature condition at −10 °C ∼ 33 °C: A case study in Qingdao, China

Multiple heat sources and extreme ambient temperatures pose more severe challenges to the safety performance of lithium-ion batteries (LIBs), and the kinetic characterization of thermal runaway (TR) of LIBs at extreme temperatures has yet to be improved. Through the establishment of a dual heat source coupled stimulation experimental platform, this study investigates the TR mechanism and flame jet dynamics of LIBs under broad temperature ranges corresponding to spring, summer, autumn, and winter (−10 °C ∼ 30 °C). The results indicate that the increase in ambient temperature leads to a gradual reduction in the TR onset time (tonset), in the order of Tonset-Winter>Tonset-Spring>Tonset-Autumn>Tonset-Summer; for example, with 100% SOC (State of Charge), Tonset-Winter = 2528 s, Tonset-Summer = 2211 s, which was accelerated by 14.3%. However, TR maximum temperature (Tmax) showed the opposite trend, Tmax-summer = 687.2 °C, Tmax-winter = 796.5 °C, which decreased by 15.9%. When SOC ≥ 75%, the average warning time for TR disaster of LIB (from venting to the beginning of TR) is 254 s less than that of winter in the summer with higher temperature, which makes the adoption of emergency measures and escape more urgent. When SOC ≥ 50%, the TR process was accompanied by flame generation, and the flame eruption process was the most intense at 100% SOC, with a maximum flame area of about 4400 cm2, and its flame temperature was likewise the highest at 986.4 °C. Carbon and metal oxides were detected in the TR ejecta, and the lower the ambient temperature, the finer the ejecta particles were. The results of the study provide an important scientific reference for improving the theory of TR of LIBs, guiding the investigation of TR and fire in new energy vehicles, and formulating relevant standards.

Root resorption of primary molars and dental development of premolars in children with Osteogenesis Imperfecta medicated with bisphosphonates, grouped according to age and gender

BackgroundOsteogenesis imperfecta (OI) is an inherited disorder characterized by bone fragility and skeletal alterations. The administration of bisphosphonates (BPs) to patients with OI reduces pain, thereby improving their quality of life. The main mechanism of action of BPs is the inhibition of osteoclast action. In the oral cavity of children with OI during growth and development, physiological processes that require the function of osteoclasts occur. The aim of this investigation was to study the dental development of premolars and the root resorption of primary molars in children with OI medicated with BPs according to age and sex.MethodsAn observational and analytical study was designed. The study sample consisted of 26 6- to 12-year-old children with a confirmed diagnosis of OI treated with BPs with available panoramic radiographs. The control group consisted of 395 children with available panoramic radiographs. Both groups were divided into subgroups according to sex and age. The third quadrant was studied, focusing on the first left temporary molar (7.4), the second left temporary molar (7.5), the first left permanent premolar (3.4) and the second left permanent premolar (3.5). The Demirjian method was used to study the dental development of 3.4 and 3.5, and the Haavikko method was used to study the root resorption of 7.4 and 7.5. The Mann‒Whitney U test was used for comparisons, and p < 0.05 indicated statistical significance.ResultsThe mean chronological age of the 421 patients was 9.21 years (95% CI 9.05–9.37). The sample was reasonably balanced by sex, with 52.5% (221 patients) boys versus 47.5% (200 patients) girls. Delayed exfoliation and tooth development were described in children with OI (p = 0.05). According to sex, the root resorption of primary molars and tooth development were significantly lower in boys in both groups and in girls in the OI group, but the differences between the age groups were not significant.ConclusionsChildren with OI treated with BPs exhibit delayed dental development of the premolars and delayed root resorption of the primary molars. Boys exhibited delays in both variables, but the differences by age subgroup were not significant. These clinical findings support the importance of clinically and radiographically monitoring the dental development and root resorption of primary teeth in children with OI treated with BPs to avoid alterations of the eruptive process.

Abnormal dental follicle cells: A crucial determinant in tooth eruption disorders (Review).

The dental follicle (DF) plays an indispensable role in tooth eruption by regulating bone remodeling through their influence on osteoblast and osteoclast activity. The process of tooth eruption involves a series of intricate regulatory mechanisms and signaling pathways. Disruption of the parathyroid hormone‑related protein (PTHrP) in the PTHrP‑PTHrP receptor signaling pathway inhibits osteoclast differentiation by DF cells (DFCs), thus resulting in obstructed tooth eruption. Furthermore, parathyroid hormone receptor‑1 mutations are linked to primary tooth eruption failure. Additionally, the Wnt/β‑catenin, TGF‑β, bone morphogenetic protein and Hedgehog signaling pathways have crucial roles in DFC involvement in tooth eruption. DFC signal loss or alteration inhibits osteoclast differentiation, affects osteoblast and cementoblast differentiation, and suppresses DFC proliferation, thus resulting in failed tooth eruptions. Abnormal tooth eruption is also associated with a range of systemic syndromes and genetic diseases, predominantly resulting from pathogenic gene mutations. Among these conditions, the following disorders arise due to genetic mutations that disrupt DFCs and impede proper tooth eruption: Cleidocranial dysplasia associated with Runt‑related gene 2 gene mutations; osteosclerosis caused by CLCN7 gene mutations; mucopolysaccharidosis type VI resulting from arylsulfatase B gene mutations; enamel renal syndrome due to FAM20A gene mutations; and dentin dysplasia caused by mutations in the VPS4B gene. In addition, regional odontodysplasia and multiple calcific hyperplastic DFs are involved in tooth eruption failure; however, they are not related to gene mutations. The specific mechanism for this effect requires further investigation. To the best of our knowledge, previous reviews have not comprehensively summarized the syndromes associated with DF abnormalities manifesting as abnormal tooth eruption. Therefore, the present review aims to consolidate the current knowledge on DFC signaling pathways implicated in abnormal tooth eruption, and their association with disorders of tooth eruption in genetic diseases and syndromes, thereby providing a valuable reference for future related research.

Reaction Rims on Ilmenite and Chromite: Implications for Volatile Behavior and Crystallization Conditions of Kimberlite Magma

Abstract Significant uncertainty surrounds the crystallization conditions and the composition of kimberlite melts, including the role of volatiles (H2O and CO2) due to their hybrid nature, intense alteration, and volatile loss during emplacement. In this study, we address these uncertainties by investigating the interaction between oxides (ilmenite and chromite) and kimberlite magma. During kimberlite ascent, mantle minerals react with the magma and develop dissolution textures, compositional zoning, and rims of secondary mineral phases in response to crystallization conditions and the composition of kimberlite magma. We examined oxides from several lithologies within the BK1 and AK15 kimberlites of the Orapa cluster in Botswana, where diamonds demonstrate distinct dissolution styles in each lithological unit owing to differences in magma saturation with volatiles. Here we discovered a strong correlation of the reaction products on ilmenite and chromite with the dissolution style of diamonds in the same kimberlite unit. Diamonds with glossy, low-relief surface features indicative of fluid-rich magma occur in the kimberlite units where ilmenite and chromite develop reaction rims of Ti-bearing phases. Diamonds with corrosion sculptures implying a volatile-undersaturated magma occur in kimberlite units with heavily resorbed chromite and ilmenite completely replaced by a MUM (magnesio-ulvöspinel-magnetite)–perovskite symplectite. Furthermore, the composition of ilmenite reaction rims depends on kimberlite lithology, where MUM co-exists with perovskite or its break-down product anatase in the two coherent kimberlite units, or with perovskite and titanite in the massive volcaniclastic unit. We examine how decompression, cooling, degassing, or assimilation of crustal rocks by kimberlite magma could have shifted conditions from perovskite to titanite stability in the volcaniclastic kimberlite unit. We propose perovskite replacement by anatase-calcite pseudomorphs in the top coherent unit, from which diamonds exhibit an overprint of fluid resorption with a melt resorption. Composition of ilmenite reaction rims provides estimates of kimberlite crystallization temperatures of 730–1275 °C and oxygen fugacities of +0.5 to −3.5 relative to the nickel-nickel oxide buffer, which are validated through controlled experiments. Our study shows that preservation of ilmenite, the type of Ti-phase in its reaction rim, the relative rate of chromite dissolution, and compositional re-equilibration with kimberlite can help model the eruption process as well as the style and rate of diamond dissolution.

3D modelling of subsurface ancient volcanic successions: a workflow developed during regional reconstructions of the Cowal Igneous Complex in the Ordovician Macquarie Arc of NSW, Australia

Mineral deposits are commonly associated with and hosted in volcanic successions. Volcanic facies analysis as applied in mineral exploration is powerful for characterising host stratigraphy to understand volcanological and eruption processes, depositional setting, and tectonic processes before, during and after ore-forming events. However, the specialist experience required in studying ancient, deformed successions impedes the uptake of facies analysis as a routinely applied technique in mineral exploration. This challenge is reflected in the literature with a paucity of examples where 3D models are developed directly from facies analysis and is worth addressing, as stratigraphic approaches are commonly inadequate for understanding and modelling the complexities within ancient volcanic terrains. We address this gap by demonstrating a technique that uses digitised graphic logs to construct correlation charts in a graphics editor to interpret ‘restored’ volcanic successions within fault blocks. This approach is validated with concurrent cross-sections that depict the structural-stratigraphic framework. The work is iteratively revised until the interpretation is internally consistent across both the correlation chart and the cross-section. This technique is presented within a four-phase workflow that guides the reader from initial scoping, through to graphic logging, interpretation of volcanic successions by locality (or fault block) and finally a synthesis and 3D model. This workflow was developed from our experiences in the buried and deformed Ordovician Cowal Igneous Complex that hosts world-class gold deposits that are currently being mined at E42 (open pit) and GRE46 (underground mine). A case study of the Cowal Igneous Complex is presented to demonstrate the value and real-world application of this workflow.

Sulfur isotopic variations in the products of the 1895 CE eruption at Zao volcano (NE Japan): Implications for connecting eruption source and syn-eruptive magmatic-hydrothermal processes

Sulfur isotopic ratio in sulfate and sulfide in subvolcanic hydrothermal systems is a valuable tracer to study the magmatic-hydrothermal processes from the magma source through to volcanic eruptions. Zao volcano is among the most active volcanoes in NE Japan, with historical explosive eruptions occurring during the last thousand years and unrest episodes since 2013. This necessitates a detailed assessment of the potential risk of future volcanic hazards. We investigated the magmatic-hydrothermal processes that occurred during the 1895 CE eruption sequence at Zao volcano by conducting mineralogical and sulfur isotope analyses in the exposed well: (i) six volcanic units (Layers 1–6) of the 1895 CE eruption products (clayish ash deposits with andesitic bombs, lapilli of scoria, and minor altered lithic fragments) deposited on the rim of Okama crater lake; and (ii) clay-altered and silicified rocks from the Nigorikawa alteration zone (NGA) surrounding the Goshikidake cone. Mineralogical data show that the samples mainly consist of alunite, pyrite, and gypsum. Alunite and pyrite occur as fine crystal mixtures associated with mineral assemblages of both advanced argillic alteration (i.e., those of cristobalite and kaolinite) and silicification (i.e., those of cristobalite, tridymite and native sulfur). Gypsum typically appears as isolated euhedral crystals of several millimeters in size. Samples of the 1895 CE eruption products have a narrow range of δ34S values from +3 ‰ to +5 ‰ for gypsum, from +9 ‰ to +13 ‰ for alunite, and approximately −10 ‰ for pyrite. For the NGA samples, the δ34Sgypsum, δ34Snative sulfur, and δ34Spyrite values range from −12 ‰ to −9 ‰, whereas for alunite, these range from +8 ‰ to +18 ‰. This indicates that alunite and pyrite in the 1895 CE eruption products were derived from the advanced argillic alteration and silicification zones that developed under Okama crater, which is exposed as the NGA. Estimated alteration temperatures based on the sulfur isotopic equilibrium between alunite and pyrite pairs are 200 °C–300 °C. By contrast, δ34Sgypsum values in the 1895 CE products are significantly higher than those in the NGA (which are derived from oxidation of pyrite or H2S, or both), ranging between an estimated parental fluid of δ34Sbulk-initial = ca. +1 ‰ and the Quaternary volcanic rocks of the Japan arc. This suggests that gypsum in the 1895 CE eruption products derived from magmatic vapor condensate (anhydrite) formed in the volcanic conduit during the eruption, thus becoming replacement of anhydrite by gypsum after or during the tephra deposition on the Zao summit surface. Our results on sulfur-bearing minerals provide new clues for better understanding (and monitoring) the syn-eruptive processes of volcanic eruptions focused on subvolcanic hydrothermal systems.

Etiological Mechanisms and Genetic/Biological Modulation Related to PTH1R in Primary Failure of Tooth Eruption.

Primary failure of eruption (PFE) is a rare disorder that is characterized by the inability of a molar tooth/teeth to erupt to the occlusal plane or to normally react to orthodontic force. This condition is related to hereditary factors and has been extensively researched over many years. However, the etiological mechanisms of pathogenesis are still not fully understood. Evidence from studies on PFE cases has shown that PFE patients may carry parathyroid hormone 1 receptor (PTH1R) gene mutations, and genetic detection can be used to diagnose PFE at an early stage. PTH1R variants can lead to altered protein structure, impaired protein function, and abnormal biological activities of the cells, which may ultimately impact the behavior of teeth, as observed in PFE. Dental follicle cells play a critical role in tooth eruption and root development and are regulated by parathyroid hormone-related peptide (PTHrP)-PTH1R signaling in their differentiation and other activities. PTHrP-PTH1R signaling also regulates the activity of osteoblasts, osteoclasts and odontoclasts during tooth development and eruption. When interference occurs in the PTHrP-PTH1R signaling pathway, the normal function of dental follicles and bone remodeling are impaired. This review provides an overview of PTH1R variants and their correlation with PFE, and highlights that a disruption of PTHrP-PTH1R signaling impairs the normal process of tooth development and eruption, thus providing insight into the underlying mechanisms related to PTH1R and its role in driving PFE.

Management of compound odontoma associated with unerupted maxillary permanent incisors: A case report

Introduction: Odontomas, the most common odontogenic tumors, result from developmental abnormalities where epithelial and mesenchymal cells grow, forming functional ameloblasts and odontoblasts. Typically asymptomatic, they are often associated with unerupted or impacted teeth. Odontomas are categorized as complex or compound, based on their tissue composition and structure. The preferred treatment is conservative surgical excision, followed by histopathological analysis for confirmation. Case History: A 13-year-old female patient came to the Pedodontic Clinic at RSGM Airlangga University with the chief complaint of unerupted upper front teeth. Intraoral eximination revealed no facial asymmetry. Intraoral examination revealed the absence of maxillary right central and lateral incisors with an asymptomatic swelling and no inflammation of the overlying mucosa. The patient had no history of systemic diseases such as heart disease or blood disorders, and there were no known allergies to food or medications. Discussion: Odontomas are generally asymptomatic and associated with unerupted or impacted teeth or retention of primary teeth. Removal of obstructions like odontome results in a spontaneous eruption of the impacted tooth. Another method currently being undertaken involves surgically exposing unerupted teeth and placing bonded attachment along with ligatures/e-chains for orthodontic traction so that it will speedup eruption process. Conclusion: The odontoma must be removed so that it will not disrupt dental growth and development, especially tooth eruption.