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Vocational teachers in building and construction in upper secondary school deal with complex situations of an organisational, vocational, and social kind. Recent research has shown that the teacher is the single most important factor for students' learning in school. Teacher-student relationships and the teacher's repertoire of teaching practices can be more important for the student's learning than class size, the classroom environment, and the student's socio-economic background. Beyond passing the journeyman's test, we know little about the craft knowledge and working life experiences vocational teachers in the building and construction trades have acquired over many years in the construction industry, and thus, what knowledge and experiences they bring into the vocational teacher role. Learning in working life often takes place as an integrated part of work, and it is difficult to observe how learning happens. Craft knowledge is often tacit and personal. In this narrative, phenomenologically inspired study, learning is investigated as a bodily, internal process that simultaneously depends on the interaction with the material and social environment. Through narrative interviews with eleven vocational teachers in plumbing and carpentry, this study explores the teachers' backgrounds as vocational students and apprentices, and their extensive experience as craftsmen on different construction sites. The analysis shows that the building site drives craft-related actions and situations that generate a strong craft identity, professional working life experiences, and personal growth. Craftsmen at the construction site work under constant pressure in a social, physically, and mentally demanding work environment and consecutively solve problems. As professional craftsmen in the complex working environment, the teachers also acquired social and organisational expertise, which they intuitively transferred to their role as vocational teachers.

A global transition to low-carbon, resource-efficient economies is occurring in response to risks posed by climate change and environmental degradation. Hydrogen is proposed as a zero-carbon substitute for natural gas with the potential to reduce carbon emissions in homes and businesses. Trades, including gasfitting, will be affected by the transition to a low-carbon economy and require upskilling to develop competencies to work with hydrogen to ensure safety and support domestic uptake. Understanding the training needs of trades practitioners is essential to the successful transition to a zero-carbon economy. This paper presents findings from a qualitative study of Australian gasfitters, exploring what motivates gasfitters to participate in training, what informs their ongoing learning and what their preferences are for hydrogen training. Most gasfitters are either self-employed or work in small businesses, and, as such, this context presents both challenges and opportunities to consider in upskilling strategies. Drawing on interview findings and literature on small business learning, the paper presents considerations to inform training approaches and policies in the transition to hydrogen and also, more broadly, for upskilling other small trade businesses similarly affected by a shift to low-carbon and green technologies.

Gukov–Pei–Putrov–Vafa conjectured the existence of q-series whose radial limits are Witten–Reshetikhin–Turaev invariants and called them homological blocks. For weakly negative definite plumbed 3-manifolds, Gukov–Pei–Putrov–Vafa and Gukov–Manolescu constructed homological blocks. In this paper, we construct indefinite false theta functions which are candidates of homological blocks for some plumbed 3-manifolds which are not weakly negative definite. Moreover we prove that, for the Poincaré homology sphere, our indefinite false theta function coincides with the original homological block. [ABSTRACT FROM AUTHOR]

We performed chlorine inactivation experiments for Elizabethkingia anophelis and E. meningoseptica bacterial strains from clinical and environmental sources. Free chlorine concentration × contact time values <0.04 mg·min/L achieved 99.9% inactivation of Elizabethkingia species, indicating chlorine susceptibility. Measures to control biofilm producing pathogens in plumbing are needed to prevent Elizabethkingia bacterial infections. [ABSTRACT FROM AUTHOR]

Indoor construction environments, with their high density and detailed components, are complex areas for progress monitoring and reporting. Traditional manual monitoring systems, often constrained by poor lighting and accessibility, are inaccurate and time-consuming. With recent technological advancements, deep learning-based object recognition models have achieved considerable attention in construction. This paper introduces a novel method for progress monitoring and reporting of construction operations, employing digital imaging and the You Only Look At CoefficienTs (YOLACT++) deep learning algorithm to automatically recognize mechanical, electrical, and plumbing (MEP) components in challenging indoor settings. Data augmentation techniques and transfer learning were applied to improve the model's generalization and adaptability. The study distinctively focuses on complex components in complicated indoor environments, a less explored area in current research that mainly centered on outdoor or simpler indoor settings. To achieve this, the study enhanced the dataset quality by generating synthetic images that closely represent actual indoor conditions including different lighting, object complexity and scale, occlusion, clutter, and viewpoints. This study also evaluated different mixes of synthetic and real images to determine the optimum combination for effective training. Moving beyond commonly used algorithms such as Mask R-CNN and You Only Look Once (YOLO), the method applied in this work is the YOLACT++ with deformable convolutional neural networks v2 (DCNv2), enhancing the model's ability to handle objects with different scales, postures, rotations, and viewpoints in the images that are essential in indoor environments. The model is validated on a large test dataset, including real images from construction sites, to cover different indoor scenarios. The model achieved a precision of 84.80% and a recall of 85.58% for HVAC duct detection and a precision of 86.87% and a recall of 73.93% for pipe detection, demonstrating its effectiveness under challenging conditions. This method contributes to more accurate automated progress monitoring in indoor environments by reducing manual and error prone inspections. [ABSTRACT FROM AUTHOR]

The traditional evaporator of water source heat pump system is easy to freeze when the water source temperature is too low in winter. A novel ice source heat pump system is proposed, which can use low temperature surface water to supply heat to buildings. One of the key problems for safe transportation is velocity range of ice slurry in ice outlet pipeline. In order to study the critical flow velocity of ice slurry in the pipe, an Euler model of horizontal straight pipe and 90° elbow pipe were established by Fluent software. The influence of five factors on the critical flow velocity of two kinds of pipes, including initial ice packing fraction, ice particle size, pipe diameter, length of straight pipe and radius curvature of elbow was studied. It found that the initial ice content should be controlled from 10% to 15%. The inlet flow rate was 20% higher than the critical flow rate under the most unfavorable condition. Ice particle size was less than 0.2 mm. The total length of ice discharge pipeline was less than 50 m. Curvature radius of the bend should be met the minimum requirements of the specification of the pipe used. [ABSTRACT FROM AUTHOR]

Disasters can prompt hydrocarbon contaminants to reach building water systems, and ultimately customer fixtures. Here, seven water supply connectors (e.g., ice‐maker lines, faucet connectors, washing machine hoses) were exposed to contaminated water, and were subsequently decontaminated by water flushing. After a 24 h contamination period, water samples were collected after three consecutive 72 h exposure periods. Samples were characterized for volatile organic compound, semi‐volatile organic compound, and total organic carbon concentrations. New, uncontaminated, PVC tubing leached phenol at concentrations that exceeded the health advisory. All materials sorbed more than 90% of hydrocarbon contaminants during the initial exposure period. All materials then released the contaminants into the water during decontamination, at times above health‐based limits. The majority of sorbed mass remained in the plastics at the end of the decontamination effort, indicating the products posed continued leaching risks. Public health guidance considerations and research needs were identified. [ABSTRACT FROM AUTHOR]

The surface gap of tephriphonolite compositions in the Passa Quatro alkaline complex, in SE Brazil, is attributed to non-buoyancy of these high viscosity intermediate compositions during magmatic fractional crystallization at different depths. Thermodynamic and Rayleigh models for three alkaline suites of a strongly silica-undersaturated series were integrated to demonstrate that parental (basanite, nephelinite and alkaline basalt) and residual (phonolites) magmas are cogenetic by fractional crystallization at pressures of 10 kbar and 5 kbar, i.e. at magma chambers located above and below the Conrad discontinuity within the Upper Cretaceous-Palaeogene 40 km-thick continental crust in SE Brazil. The fractional crystallization of the parental magmas produced an ultramafic residual solid (wehrlite, olivine-bearing clinopyroxenite and clinopyroxenite) and residual liquids (evolved basanite and alkaline basalt, and phonotephrite). The latter moved up and built magma chambers at lower depths in the continental crust where those magmas initially crystallized clinopyroxenite extracts and high viscosity residual liquid that was entrapped and prevented to ascent towards the surface. Then, an abrupt change in the extract mineralogy produced a feldspathic-rich extract (leucocratic leucite monzosyenite, mesocratic syenite or leucocratic monzodiorite) and a residual phonolitic liquid with low viscosity. Following the feldspar crystallization, the magma viscosity decreased, acquiring adequate buoyancy that resulted in shallow-crust magma chambers in which phonolite diversification took place. These processes occurred due to the existence of a transcrustal, plumbing architecture where the high viscosity intermediate tephriphonolites were prevented to reach shallower depths, resulting in the Daly gap observed in the Passa Quatro Alkaline Complex. [ABSTRACT FROM AUTHOR]

For active volcanoes, knowledge of the architecture of the plumbing system and the conditions of magma storage prior to an eruption are highly important, given their influence on the eruptive style and, thus, the management of future volcanic crises. Here, chlorine is used as a geobarometer for potassic alkaline magmas at the Campi Flegrei volcanic complex, revealing the shallowest depth of fluid-melt equilibration with respect to Cl. The results for representative fallout deposits of selected explosive eruptions show the existence of a multi-depth equilibration zone through time, including shallow magma storage. We describe evidence for the shallowest zone located at a depth equivalent to 65 MPa for the Agnano Monte Spina eruption (4482–4625 cal. yrs BP), at ~100 MPa for the Pomici Principali (11 915–12 158 cal. yrs BP), and the Astroni 6 (4098–4297 cal. yrs BP) eruptions, and close to 115 MPa for the last explosive eruption of Monte Nuovo (AD 1538). For comparison, the pressure estimated for a possible reservoir feeding the Cretaio eruption of Ischia island (AD 430), the only studied eruption on Ischia, is ~140 MPa. The pressure estimates for the two largest magnitude eruptions, the Campanian Ignimbrite (40 ka) and the Neapolitan Yellow Tuff (14.9 ka), are also discussed with respect to available magma withdrawal models. The pressures estimated using the Cl geobarometer for the magma leading to the fallout phases of these two eruptions provide evidence for a low-volume, shallow domain (~40 MPa) for the Plinian phase of the Campanian Ignimbrite eruption and a main, deeper reservoir (~130–165 MPa) for the Neapolitan Yellow Tuff eruption. The inferred shallowest equilibration pressures are interpreted here as corresponding to transitory, short-lived magma apophyses, whose eruption may have been facilitated by optimum tectonic stresses, rheological behavior of the crust, and efficiency of volatile exsolution. Alternatively, these magma apophyses may represent an evolved, crystal-rich ponded magma into which a volatile-rich magma ascending from depth was injected. The transient nature of such very shallow reservoirs is suggested by the short timescales inferred from diffusion modeling on crystals available in the literature for the studied Campi Flegrei eruptions. The influence of sulfur (S) on Cl solubility is assessed through Cl solubility modeling and applied to different eruptions. In addition, the pressure at which magmatic fluids and melts equilibrated with respect to Cl is shallower for the Campi Flegrei volcanic complex than the Somma-Vesuvio volcanic complex, erupting more homogeneous differentiated magma, of trachytic or phonolitic composition. This approach of using Cl to investigate the architecture of the plumbing system can be extended to all alkali-rich magma systems. [ABSTRACT FROM AUTHOR]

The architecture of magma plumbing systems plays a fundamental role in volcano eruption and evolution. However, the precise configuration of crustal magma reservoirs and conduits responsible for supplying eruptions are difficult to explore across most active volcanic systems. Consequently, our understanding of their correlation with eruption dynamics is limited. Axial Seamount is an active submarine volcano located along the Juan de Fuca Ridge, with known eruptions in 1998, 2011, and 2015. Here we present high-resolution images of P-wave velocity, attenuation, and estimates of temperature and partial melt beneath the summit of Axial Seamount, derived from multi-parameter full waveform inversion of a 2D multi-channel seismic line. Multiple magma reservoirs, including a newly discovered western magma reservoir, are identified in the upper crust, with the maximum melt fraction of ~15–32% in the upper main magma reservoir (MMR) and lower fractions of 10% to 26% in other satellite reservoirs. In addition, a feeding conduit below the MMR with a melt fraction of ~4–11% and a low-velocity throat beneath the eastern caldera wall connecting the MMR roof with eruptive fissures are imaged. These findings delineate an asymmetric shallow plumbing system beneath Axial Seamount, providing insights into the magma pathways that fed recent eruptions. This study illustrates an asymmetric magmatic plumbing system beneath Axial Seamong along Juan de Fuca ridge. The work provides insights into the magma pathways that fed recent eruptions. [ABSTRACT FROM AUTHOR]

Increasing regulatory and market changes that decouple fossil fuels from the built environment will require existing trade practitioners to upskill. However, the structure of the construction sector, which includes short-term contracts, tight deadlines, high reliance on contingent labor, and a large proportion of small-business contractors who are responsible for their own training makes upskilling challenging. Consideration of the industry's structure and the characteristics of small trade business learning practices is necessary for any upskilling program. Plumbing is a key example of a trade requiring upskilling for a low-carbon economy. The gas fitting component of plumbing work will change dramatically with the phasing out of carbon-producing natural gas and substitution with alternatives such as hydrogen. This study used a survey of 1,001 Australian plumbers, informed by the theory of planned behavior (TPB), to understand the learning contexts and needs of plumbers in upskilling and ascertain attitudinal, social, and structural enablers for training behavior. The results show that attitudes to training, including the perceived benefits of training for skills development and end-user safety, are the key motivator for plumbers' training behavior, whereas social norms and behavioral controls such as time and cost are somewhat influential. The findings provide insight into training behavior enablers that can be leveraged to support the roll-out of upskilling for low-carbon technologies and ongoing trades training programs more broadly. [ABSTRACT FROM AUTHOR]

A global transition to low-carbon, resource-efficient economies is occurring in response to risks posed by climate change and environmental degradation. Hydrogen is proposed as a zero-carbon substitute for natural gas with the potential to reduce carbon emissions in homes and businesses. Trades, including gasfitting, will be affected by the transition to a low-carbon economy and require upskilling to develop competencies to work with hydrogen to ensure safety and support domestic uptake. Understanding the training needs of trades practitioners is essential to the successful transition to a zero-carbon economy. This paper presents findings from a qualitative study of Australian gasfitters, exploring what motivates gasfitters to participate in training, what informs their ongoing learning and what their preferences are for hydrogen training. Most gasfitters are either self-employed or work in small businesses, and, as such, this context presents both challenges and opportunities to consider in upskilling strategies. Drawing on interview findings and literature on small business learning, the paper presents considerations to inform training approaches and policies in the transition to hydrogen and also, more broadly, for upskilling other small trade businesses similarly affected by a shift to low-carbon and green technologies. [ABSTRACT FROM AUTHOR]

Lamprophyres are spatially and temporally widespread in continental belts, but their magmatic differentiation process and melting dynamic mechanisms remain subjects of debate. In this study, we report mineral chemistry, bulk-rock compositions, and Sr-Nd-O isotopes of the alkaline lamprophyres (including monchiquite and camptonite) from the Tuoyun Basin of the southwestern Central Asian Orogenic Belt. Based on the P-T estimates, transcrustal magmatic reservoirs from the lower crust to upper crust are revealed for monchiquite and camptonite. These magmatic reservoirs were potentially connected, and the magmatic recharge and mixing processes that occurred were recorded by zoned clinopyroxene and amphibole. The diverse crystal populations are suggested to have originated from multiple batches of magmas, which were then involved in forming the subsequent magmas. The Sr-Nd isotopic compositions are relatively depleted, with (87Sr/86Sr)i = 0.70390-0.70452 and εNd(t) = 5.46-6.49 for the monchiquite, while the values for camptonite are 0.70391-0.70463 and 4.71-5.02. Moreover, the olivine in situ O isotopes in the monchiquite show Î'18OV-SMOW values of 4.81‰-5.40‰, which are comparable to those of the mantle peridotite. Compared with the experimental melts, a hybridized mantle source of hydrous peridotite + silica-depleted pyroxenite is proposed, and partial melting of this component was induced by the upwelling asthenosphere. Ultimately, our study highlights the critical role of the magmatic plumbing system and hydrous mantle source in the formation of Tuoyun lamprophyres. [ABSTRACT FROM AUTHOR]

Determining the time spans of processes related to the assembly of eruptible magma at active volcanoes is fundamental to understand magma chamber dynamics and assess volcanic hazard. This information can be recorded in the chemical zoning of crystals. Nevertheless, this kind of study is still poorly employed for the active volcanoes of the Neapolitan area (Southern Italy), in particular, for Ischia island where the risk is extremely high and this information can provide the basis for probabilistic volcanic hazard assessment. For these reasons, we acquired chemical composition on clinopyroxene crystals erupted at Ischia during the Zaro eruption (6.6 ± 2.2 ka) and performed numerical simulations of the input of mafic magma into a trachytic reservoir, in order to investigate various aspects of pre-eruptive dynamics occurring at different timescales. This event emplaced a ~ 0.1 km3 lava complex, in which the main trachytic lava flows host abundant mafic to felsic enclaves. Previous petrological investigation suggested that mafic magma(s) mixed/mingled with a trachytic one, before the eruption. In this work, the clinopyroxene zoning patterns depict the growth of crystals in different magmatic environments, recording sequential changes occurred in the plumbing system before the eruption. The evolution of the plumbing system involved a hierarchy of timescales: a few hours for magma mingling caused by mafic recharge(s) and likely occurred multiple times over a decade during which a dominant magmatic environment was sustained before the eruption. Such timescales must be considered in volcanic hazard assessment at Ischia and similar active volcanoes in densely populated areas. [ABSTRACT FROM AUTHOR]

The Pleiades Volcanic Field (PVF) of northern Victoria Land (Antarctica) is made up of a dozen scoria cones whose erupted products present an unusually complete evolutionary trend from alkali-basalt to trachyte. With the aim of reconstructing the evolution of the PVF plumbing system, we have investigated the petrography and chemistry of main mineral phases using scanning electron microscopy (SEM-EDS) coupled with major element analyses using an electron probe microanalyser (EPMA-WDS). We further focussed on clinopyroxene phenocrysts obtaining a more detailed characterization by means of trace laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) element analyses coupled with machine learning thermobarometry. The results indicate that fractional crystallization and magma mixing are the major processes determining the development of the complete evolution trend. While fractional crystallization is a persistently active process in all parts of the plumbing system, mixing among differently evolved magma batches pertaining to the same association is responsible for the formation of intermediate compositions in the differentiation lineage at a specific pressure range (0.4–0.5 GPa). These processes are compatible with significant residence time of magmas at depth, resulting in multiple episodes of magma mixing, as testified by resorption and overgrowth textures in phenocryst assemblage occurring under isobaric conditions. The prolonged residence time likely increased the efficiency of the mixing process, leading to the formation of magmas with intermediate composition. In turn, the build-up of volatiles during the magma differentiation at depth could have favoured the eruption of these (variably differentiated) magmas. Considering that the PVF is situated in a glacial region, a process forcing long magma residence time can be envisaged associated with increased ice loading during glacial stages. This study specifically considers the ice fluctuations in the last 100 ka, theorizing the possibility of a climate-controlled volcano plumbing system. [ABSTRACT FROM AUTHOR]

Teagasc, the state agency for research, training and advice, and the Department of Agriculture, Food and the Marine (DAFM) have collaborated on the development of a testing protocol for <3m boom sprayers in Ireland. An informal survey indicated that there was an array of <3m boom sprayers on the Irish markket with varying specifications. From that survey and examination of sprayers with varying specifications, this paper presents the range of equipment and some of the problems encountered. The issues varied from basic like no basket filter, but some were more complex like the layout of the plumbing systems, the type and size of pumps, the lack of control, pressure adjustment, relief valves etc. A challenging factor for testing is that frequently these sprayers when sold for mounting on a Quad type ATV are sold as two seperate parts. The units are not that expensive so the test cost needs to be pitched so that it does not encourage immediate replacement with a new sprayer, which could result in new sprayers that would not pass a test continually replacing older models avoiding the test procedure. Also the sprayer and the boom are not being sold as one unit. One box contains the spray tank and lance, and as this is not a boom sprayer is does not require to be tested. The second item is a boom which can be attached to the spray tank and lance, and it is only when the boom is attached that the unit falls into the requirement for a test. So if a farmer only requires to have his machine tested after 3 years can he buy a new boom or alternatively a new spray tank unit and then exempt himself from the test. [ABSTRACT FROM AUTHOR]

Mechanical, electrical, and plumbing (MEP) system experts often have difficulties in converting their designs, in computer-aided design (CAD), into building information models (BIMs) owing to excessive repetitive work, lack of BIM skilled workers, frequent BIM recreations, etc. Therefore, this study aimed to formalize the CAD-to-BIM process of MEP systems, focusing on sanitary plumbing system, including soil, drain system, hot water supply, and cold water supply system. Each system's process is composed of a combination of the following five common modules: pipeline processing module, pipe connection module, initial level setting module, addition riser nipple module, and clash resolution module. Consequently, a prototype developed based on the formalized process produced a sanitary plumbing BIM model that is identical to the CAD drawings and has no clashes. This study contributes to the MEP BIM theory by identifying considerations for CAD-to-BIM conversion of sanitary plumbing system and formalizing the process reflecting them. [ABSTRACT FROM AUTHOR]

Volcanoes produce a variety of seismic signals and, therefore, continuous seismograms provide crucial information for monitoring the state of a volcano. According to their source mechanism and signal properties, seismo‐volcanic signals can be categorized into distinct classes, which works particularly well for short transients. Applying classification approaches to long‐duration continuous signals containing volcanic tremors, characterized by varying signal characteristics, proves challenging due to the complex nature of these signals. That makes it difficult to attribute them to a single volcanic process and questions the feasibility of classification. In the present study, we consider the whole seismic time series as valuable information about the plumbing system (the combination of plumbing structure and activity distribution). The considered data are year‐long seismograms recorded at individual stations near the Klyuchevskoy Volcanic Group (Kamchatka, Russia). With a scattering network and a Uniform Manifold Approximation and Projection (UMAP), we transform the continuous data into a two‐dimensional representation (a seismogram atlas), which helps us to identify sudden and continuous changes in the signal properties. We observe an ever‐changing seismic wavefield that we relate to a continuously evolving plumbing system. Through additional data, we can relate signal variations to various state changes of the volcano including transitions from deep to shallow activity, deep reactivation, weak signals during quiet times, and eruptive activity. The atlases serve as a visual tool for analyzing extensive seismic time series, allowing us to associate specific atlas areas, indicative of similar signal characteristics, with distinct volcanic activities and variations in the volcanic plumbing system. Plain Language Summary: Volcanoes generate diverse seismic signals, and analyzing continuous seismograms can offer valuable insights into a volcano's behavior. However, classifying and cataloging these signals is challenging, particularly for long‐period signals such as volcanic tremors with varying signal characteristics. In this study, we utilize seismic time series data from the Klyuchevskoy Volcanic Group in Russia, employing machine learning and signal processing methods to transform and represent the time series data. The resulting "seismogram atlas" helps identify changes in signal properties, revealing a dynamic seismic wavefield linked to the evolving plumbing system of the volcano. This approach provides a comprehensive understanding of the volcanic behavior in time by connecting signal variations to different volcanic states, such as shifts in activity depth, reactivation, and eruptive periods. These findings highlight the unique characteristics of continuous seismograms near the volcano, suggesting that there is valuable information in the complete seismic time series that conventional methods and event catalogs may miss. Key Points: With machine learning, we analyze 1 year long seismic time series at individual stations at Klyuchevskoy volcanoContinuous evolution of the signal characteristics over time reflects dynamic changes occurring in the volcano plumbing systemDifferent episodes of volcanic activity are well distinguished on UMAP‐based seismogram atlases [ABSTRACT FROM AUTHOR]

The application of whole-rock compositions to trace magma evolution or crystal-melt equilibrium may be called into question when foreign crystals are incorporated into host magmas. To address this challenge, establishing the origins (orthocrysts, antecrysts, xenocrysts, etc.) of minerals with variable textures in magmatic plumbing systems is necessary. In this paper, we describe complex oscillatory zoning patterns of clinopyroxenes (Cpx) from the Miocene Majuangou (MJG) alkali basalts from West Qinling, China. Our detailed petrographic, mineralogical, and geochemical analyses unravel the origins of various Cpx crystals with distinct textural patterns, thereby providing information about magma storage, recharging and/or mixing, and transportation, as well as the reactions between crystals and melts/fluids. Based on textural patterns, Cpx may be divided into four types: normal (Type-1 Cpx), simple oscillatory (Type-2 Cpx), complex oscillatory (Type-3 Cpx), and grains that lack zoning (Type-4 Cpx, suggested to be orthocrysts). Through the textural characterization of Cpx, the comparison between different types of Cpx, and the relationships between Cpx major compositions from different lithologies, we concluded that Type-1–3 Cpx cores are antecrysts or xenocrysts with diverse origins: primitive magma (Type-1 Cpx cores), magma mush (Type-2 Cpx cores), and crustal granulite (Type-3 Cpx cores). The zoning patterns and the compositions of these Cpx crystals indicate at least three batches of magmatic activity, i.e., the Batch-1 low-Mg# magma (Mg#: 47.4–53.3), the Batch-2 primitive magma (Mg#: 57.2–64.5), and the Batch-3 low-Mg# host alkali magma (Mg#: 47.2–54.6). Cpx-melt thermobarometry demonstrates that at least two crustal magma reservoirs existed in the magma plumbing system at depths of 30.1 and 40.9 km. The antecrystic/xenocrystic Cpx cores were captured by, continued to grow in, and subsequently reacted with ascending K-rich melt/fluid. The spongy textures in Cpx cores/mantles are attributed to this reaction, which may be expressed as: Melt 1 (primitive or evolved) + K-rich melts/fluids + Cpx (CaMgSi2O6) = K-feldspar (KAlSi3O8) + ilmenite (FeTiO3) + Melt 2 (derivative). The products of this reaction (K-feldspar and ilmenite) filled the sieves in the spongy zones of Type-1–3 Cpx. This detailed investigation of compositional and textural features of Cpx antecrysts/xenocrysts suggests that the interactions between various interconnected magma reservoirs are widespread beneath the magmatic plumbing system. Our study emphasizes the importance of the incorporation of foreign crystals and the Cpx-melt/fluid reaction in magmatic plumbing system, which can significantly modify the whole-rock compositions and lead to the formation of spongy textures without the need for fractures and cracks in minerals. [ABSTRACT FROM AUTHOR]

Modelling plumbing systems dynamics of active volcanoes through textural and chemical studies of mineral phases is crucial to unravel their eruptive behaviour, but it is rarely applied in ancient volcanic and volcano-plutonic systems. Here, we present an investigation of the architecture, magma dynamics and pre-eruptive timing of Middle Triassic plumbing systems in the Dolomites area (Southern Alps) through a detailed investigation of textures and compositional zoning of clinopyroxenes in lavas and dykes from Predazzo, Mt. Monzoni, Cima Pape and Sciliar volcano-plutonic complexes. The clinopyroxene composition varies between low-Mg# (67–78), low-Cr augite and high-Mg# (77–91), Cr-rich diopside. Diopside is less frequent and appears as variably thick single or multiple bands between augitic cores and rims or as resorbed homogeneous, or patchy-zoned and mottled cores. Rims are homogeneous or oscillatory zoned, with augitic composition. The mid- to low-crustal plumbing systems of all volcanic centres were characterised by the presence of a mildly evolved trachyandesitic magma (Mg# 45; T = 1044–1118 °C), where augitic clinopyroxene formed. Periodic mafic injections of more primitive and hotter trachybasaltic magma (Mg# 56; T = 1056–1170 °C) caused frequent crystallisation of diopsidic bands around augitic cores. The presence of resorbed or patchy-zoned mottled diopsidic cores in clinopyroxene phenocrysts, as well as of rare clinopyroxenitic xenoliths with analogous diopsidic composition, indicates the recycling and remobilisation of antecrysts from the deeper part of the plumbing system, which was probably located at a depth of 10–17 km. Diffusion chronometry models based on Fe–Mg interdiffusion in clinopyroxene revealed that the time elapsed from the mafic injection into the shallow portion of the plumbing systems to the eruption ranges from decades to < 1 year. Our findings enabled us to resolve the different plumbing system dynamics acting at the local scale beneath each volcanic centre. Our data indicate a striking similarity with magma dynamics and timing of pre-eruptive processes at active volcanoes: therefore, we posit that this work sets a starting point to deepen our knowledge of the volcano-plutonic links and, in turn improves our ability to interpret the main processes acting in active plumbing systems. [ABSTRACT FROM AUTHOR]

Processes taking place within the magma plumbing system can exert an important control on the composition of mid-ocean ridge basalts (MORB). Plagioclase ultraphyric basalts (PUBs) found at magma-poor mid-ocean ridges exhibit diverse disequilibrium characteristics, which can provide vital insights for distinguishing the complex effects of melt transport from those of source heterogeneity on the compositions of MORBs. Here, we present new insights into magmatic processes using integrated petrologic and geochemical studies of the PUBs from two zones (~ 50° and ~ 64°E longitude) along the ultraslow-spreading southwest Indian ridge (SWIR). The studied PUBs have complex mineral morphologies, including skeletal and acicular crystals, glomerocrysts with open and closed structure, reverse and normally zoned crystals and external and internal resorption even in single samples. Both low- and high-Fo olivine and An plagioclase crystals are in disequilibrium with their matrix glasses. Some plagioclase phenocrysts have repeated oscillatory zoning (An77–86) going from their core to rim and an abrupt decrease in An content toward the rim. Disequilibrium Sr isotopic compositions are present at several scales: between cores and rims of plagioclase crystals, between different plagioclase crystals and between plagioclase and their host lavas. Inferred pressures of magma storage range from 0.3 to 11.3 kbar. The textural and compositional diversity of crystals together with the variability in melt compositions reflect the combined influences of source heterogeneity and magmatic processes (e.g. crystallization, assimilation and magma mixing processes) taking place within crystal mushes. Our data combined with previous studies suggest that the magmatic processes within the SWIR magma plumbing system involve formation, disaggregation and juxtaposition of crystal-rich mush zones. [ABSTRACT FROM AUTHOR]

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