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The Yuli belt in eastern Taiwan attests to tectonic evolution involving subduction metamorphism because two metamélange units contain high-pressure (HP) blocks or layers of metaigneous rocks and serpentinites enclosed in metasedimentary schists. Metasomatic reaction zones occur locally along the contact between serpentinite (SP) and pelitic schist (PS). In the Tsunkuanshan area, we recognized five metasomatic zones. From PS to SP, the dominant minerals in each zone are: (I) albite, chlorite, phengite; (II) albite, amphibole, biotite, stilpnomelane; (III) chlorite, phengite, albite, epidote; (IV) epidote, chlorite, albite; and (V) talc, chlorite. Minor garnet and glaucophane are present in zone I and II, respectively. Field and petrographic observations combined with whole-rock major elements data suggest that this rock association was formed by diffusive exchanges between the PS and SP. Zones I - IV and PS samples show identical rare earth element (REE) patterns, indicating that these zones are of PS protolith. Hence, the original boundary between the PS and SP is likely in the zone IV and V. The isocon method was applied to quantify the mass balance among the metasomatic zones. The result shows mass changes in zones: I: +12%; II: -4%; III: +50%; IV: +56%. Enrichment of Ca is present in the entire reaction zones, especially the zone IV (up to 91%), whereas Na is only enriched within the zone I (~80%) and II (~89%). These enrichments are likely due to the involvement of external fluids. The formation of these metasomatic rocks was not only controlled by diffusive exchanges between PS and SP, but also by the Na and Ca rich fluid infiltrations. The existence of glaucophane within the zone II indicates that the metasomatism occurred under HP metamorphic conditions in a paleo-subduction interface.Keywords: Fluid-rock interactions, isocon method, Na and Ca rich fluids, high-pressure, Yuli belt.

Context Individuals with diabetes mellitus (DM) are susceptible to various infections. Objective We estimated the risk of herpes zoster (HZ) among individuals with DM compared with individuals in the general population. Methods We searched the PubMed, Embase, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, and PerioPath databases from their inception to January 30, 2021, for studies on the risk of HZ in individuals with DM. Two authors independently screened all articles identified. The same 2 authors independently extracted the data. Four case-control studies and 12 cohort studies were included. Results Meta-analyses were performed using fixed and mixed-effects models. In the pooled analysis, individuals with DM had a higher risk of developing HZ (pooled relative risk [RR]: 1.38; 95% CI, 1.21-1.57) than individuals in the general population. The results were consistent in subgroup analyses stratified by type of diabetes, age, and study design. In individuals with DM, cardiovascular disease had an additive effect on increasing the risk of HZ (pooled RR: 1.19; 95% CI, 1.11-1.28). There was a linear dose-response association between age and the risk of HZ in individuals with DM. Conclusion Individuals with DM have an increased risk of HZ compared with the general population. Varicella vaccination should be provided to individuals with DM regardless of their age, prioritizing older adults and those with cardiovascular disease. Varicella vaccination policies for individuals with DM should be updated based on the evidence.

Metasomatic rocks in orogenic mélanges bear critical information about fluid-rock interactions and element mobilities during subduction processes. The Yuli belt contains a few mélange units that crop out high-pressure blocks of metaigneous rocks and serpentinites enclosed in metasedimentary rocks. Metasomatic rocks are found along contacts between the serpentinites and metasedimentary rocks. However, the protolith and formation of those metasomatic rocks are largely unknown. Meter-scale metasomatic zones occur at the contact between pelitic schists (PS) and serpentinites (SP) in the Tsunkuanshan area. Five zones from PS to SP are newly identified: (I) chlorite-albite schist, (II) amphibole-albite rock, (III) albite-chlorite schist, (IV) epidote-chlorite schist, and (V) chlorite-talc schist. Minor garnet and amphibole (glaucophane core - barroisite mantle - actinolite rim) are present in the zone I and II, respectively. Field and petrographic observations combined with whole-rock major elements data suggest that this rock association likely was formed by chemical exchanges between the SP and PS. However, the zone II shows enrichment of Si, Na, and Ca, but Al depletion relative to the other metasomatic rocks. This anomaly might be due to infiltration of external fluids. Rare earth element patterns of the PS, zone I, II, III, and IV are similar, indicating a similar protolith origin. Hence, the original boundary between the PS and SP is likely between the zone IV and V. We estimate the chemical mass balance from the PS to the metasomatic rocks (zone I, II, III, and IV) using the sparse isocon method (Kuwatani et al., 2020). The result shows that the chemical components in zone I, III, and IV are gained relative to the PS, whereas those in zone II are of loss. We interpret that the zone I, III, IV, and V were produced by diffusive exchanges of components between the PS and SP, whereas formation of the zone II was likely created by Na-Ca rich fluid infiltrations. The newly-found occurrence of glaucophane within the zone II indicates fluid-rock interactions during subduction metamorphism.Keywords: Chemical mass balance, sparse isocon method, Na-Ca rich fluids, Yuli belt.

OBJECTIVE Temporary vascular access (TVA) is frequently used during the first dialysis in patients with chronic kidney disease (CKD), and it is associated with an increased risk of infection, central vein stenosis, and mortality. Here, factors associated with TVA in patients with CKD were explored. METHODS This study included patients in a single-center CKD care program who initiated long-term renal replacement therapy. The primary outcome was TVA use at first dialysis. Factors possibly associated with TVA use were analyzed using Cox regression. RESULTS Temporary vascular access was used in 53.2% of the patients at first dialysis. In total, 73.2% (n = 865) and 26.8% (n = 317) of the patients were on hemodialysis and peritoneal dialysis, respectively. Multivariate Cox regression analysis showed that TVA use in patients with CKD was associated with diabetes (hazard ratio [HR] 1.52, 95% confidence interval [CI] 1.28-1.81, p

Femtosecond lasers at fixed wavelengths above 1,000 nm are powerful, stable and inexpensive, making them promising sources for two-photon microscopy. Biosensors optimized for these wavelengths are needed for both next-generation microscopes and affordable turn-key systems. Here we report jYCaMP1, a yellow variant of the calcium indicator jGCaMP7 that outperforms its parent in mice and flies at excitation wavelengths above 1,000 nm and enables improved two-color calcium imaging with red fluorescent protein-based indicators. jYCaMP1, a yellow variant of the calcium indicator jGCaMP7, enables fast multicolor two-photon imaging at excitation wavelengths above 1,000 nm for use with popular ytterbium-doped fiber and modelocked semiconductor lasers.

Background: Urothelial carcinoma of the bladder (UCB) is the second most common genitourinary cancer. This study aims to assess the diagnostic accuracy of CA125 in advanced UCB. Methods: We searched prevalent studies in PubMed, the Cochrane Library, Scopus, Embase, the Web of Science China National Knowledge Infrastructure database, and Wanfang data before October 2022. Pooled sensitivity, specificity, and summary receiver operating characteristics were used to assess the diagnostic value of CA125. Results: One thousand six hundred forty-one patients from 14 studies were analyzed. UCB stage T3–4N1 was defined as advanced UCB in ten studies; T2–4 was used in three studies; and N1M1 in one study. Patients’ age was between 21 to 92, and 21% to 48.6% of patients were female. The pooled sensitivity was 0.695 (95% confidence interval (CI): 0.426–0.875). The pooled specificity was 0.846 (95% CI: 0.713–0.924). The diagnostic odds ratio was 8.138 (95% CI: 4.559–14.526). The AUC was 0.797. Conclusion: CA125 may provide significant diagnostic accuracy in identifying muscle-invasive, lymph node-involved, and distant metastatic tumors in patients with urothelial carcinoma of the bladder. Limited studies have been conducted on the prognostic role of CA125. More studies are needed for a meta-analysis on the prognostic role of CA125 in UCB.

The provenance of sediments in western Taiwan has been the subject of debate in recent years. Previous investigators, solely based on the U-Pb zircon geochronology for the detrital grains, all advocated the important roles, but with varying emphasis, of drainage systems in the South China Block. Influence of the Changjiang (Yangtze) River from the far-source Yangtze block versus nearby systems like Zhujiang, Minjiang and Jiulongjiang Rivers in the Cathaysia block has been the main issue. However, the fundamental question of whether the provenance is really the South China Block has never been evaluated. Here we report both the U-Pb zircon and Electron MicroProbe (EMP) monazite age data for seven sediment samples from two sides of the Taiwan Strait and synthesize the published data for all these rivers and sedimentary strata in western Taiwan to tackle this problem. The lack of, or insufficient, ~1.8 Ga monazites in the sediments of river mouths for all drainage systems in the South China Block makes them unlikely to be the source of Miocene sediments in western Taiwan where ~1.8 Ga monazite grains occupy 14.5–33.3% of the total age population. With reference to the tectonic evolution of the coastal southeast China-Taiwan region during Early Cretaceous to recent time, we propose a new explanation that invokes a now-concealed microcontinent along the Manila Trench. This microcontinent, probably related to a Paleoproterozoic orogen in Gondwana, eventually collided with the South China Block causing uplift of the easternmost structural element—the Pingtan-Dongshan Metamorphic Belt (PDMB) at ca. 130–120 Ma. It then drifted away sometime after 100 Ma and split into two parts with one becoming today's Palawan-Mindoro terrain of the Philippines. As indicated by the geophysical data near southern Taiwan, the remainder of this split microcontinent had subducted underneath the Philippine Sea plate along Manila Trench as a result of the opening of the South China Sea at ~33 Ma. Both the Peikang and Kuanyin basement highs in the offshore western Taiwan represent the unsubducted remnants of this microcontinent and also the major suppliers of Late Oligocene-Miocene sediments in western Taiwan. On the other hand, the Eocene-Early Oligocene strata of the Hsuehshan Range in central Taiwan show both zircon and monazite age patterns resembling the Eocene-Early Oligocene and recent sediments of the Zhujiang drainage system, indicating the southwestern origin of the protolith Taiwan. This scenario also matches the recent proposition that part of the Central Range belongs to the deep-level accretionary prism of a Miocene subduction system.

Real-time rendering of closed-loop visual environments is important for next-generation understanding of brain function and behaviour, but is often prohibitively difficult for non-experts to implement and is limited to few laboratories worldwide. We developed BonVision as an easy-to-use open-source software for the display of virtual or augmented reality, as well as standard visual stimuli. BonVision has been tested on humans and mice, and is capable of supporting new experimental designs in other animal models of vision. As the architecture is based on the open-source Bonsai graphical programming language, BonVision benefits from native integration with experimental hardware. BonVision therefore enables easy implementation of closed-loop experiments, including real-time interaction with deep neural networks, and communication with behavioural and physiological measurement and manipulation devices.

Real-time rendering of closed-loop visual environments is necessary for next-generation understanding of brain function and behaviour, but is prohibitively difficult for non-experts to implement and is limited to few laboratories worldwide. We developed BonVision as an easy- to-use software for display of virtual or augmented reality as well as standard visual stimuli. As the architecture is based on the open-source Bonsai graphical programming language, BonVision benefits from Bonsai’s native integration with experimental hardware. BonVision therefore enables easy implementation of closed-loop experiments and communication with behavioural and physiological measurement and manipulation devices, while being open-source, easy to install, and able to run on standard personal computers.

Sleep and wake have global effects on brain physiology, from molecular changes1–4 and neuronal activities to synaptic plasticity3–7. Sleep–wake homeostasis is maintained by the generation of a sleep need that accumulates during waking and dissipates during sleep8–11. Here we investigate the molecular basis of sleep need using quantitative phosphoproteomic analysis of the sleep-deprived and Sleepy mouse models of increased sleep need. Sleep deprivation induces cumulative phosphorylation of the brain proteome, which dissipates during sleep. Sleepy mice, owing to a gain-of-function mutation in the Sik3 gene 12 , have a constitutively high sleep need despite increased sleep amount. The brain proteome of these mice exhibits hyperphosphorylation, similar to that seen in the brain of sleep-deprived mice. Comparison of the two models identifies 80 mostly synaptic sleep-need-index phosphoproteins (SNIPPs), in which phosphorylation states closely parallel changes of sleep need. SLEEPY, the mutant SIK3 protein, preferentially associates with and phosphorylates SNIPPs. Inhibition of SIK3 activity reduces phosphorylation of SNIPPs and slow wave activity during non-rapid-eye-movement sleep, the best known measurable index of sleep need, in both Sleepy mice and sleep-deprived wild-type mice. Our results suggest that phosphorylation of SNIPPs accumulates and dissipates in relation to sleep need, and therefore SNIPP phosphorylation is a molecular signature of sleep need. Whereas waking encodes memories by potentiating synapses, sleep consolidates memories and restores synaptic homeostasis by globally downscaling excitatory synapses4–6. Thus, the phosphorylation–dephosphorylation cycle of SNIPPs may represent a major regulatory mechanism that underlies both synaptic homeostasis and sleep–wake homeostasis.

Wuyishan is one of the most important terrains exposing the Precambrian basement of the Cathaysia Block, South China. Conventionally, Paleoproterozoic and Neoproterozoic sequences have been proposed in this terrain, however, the thermal histories affecting each unit within these sequences remain unclear. We report here spot analysis of 448 LA-ICPMS U-Pb zircon and >1600 EMP Th-U-Pb monazite ages for twenty samples, including schist, gneiss, migmatite and amphibolite, from different units within the basement. U-Pb zircon dating yield some concordant Neoproterozoic and/or Early Paleozoic age clusters with a wide spread of Neoarchean to Mesoproterozoic inherited ages (except amphibolite), indicating the formation of the Mayuan/Chencai core in the Early Neoproterozoic (887–827 Ma) and peripheral units in two stages of the Late Neoproterozoic (746–731 Ma and 681–660 Ma). The in-situ EMP monazite analyses give consistent Early Paleozoic ages (440–426 Ma) from inclusions in various host minerals for all but two samples from same locality that are Triassic in age (239–237 Ma). A large population of Early Paleozoic interstitial monazites shows breakdown texture and ages of secondary monazites range from 376 Ma to 358 Ma, conforming with the U-Pb zircon age of the amphibolite (370 ± 5 Ma). A few samples exhibit relict ages of ∼540 Ma from monazite cores. We conclude that the Wuyishan terrain is dominated by Early and Late Neoproterozoic basement sequences related to collisional and continental rifting orogenies, respectively, while the Badu Group in Zhejiang as a Paleoproterozoic protolith. The Neoproterozoic basement incorporating some Early Cambrian detritus, has thoroughly metamorphosed during the Silurian and further affected by the regional fluid-aided metasomatism coeval with the basic magma, now represented by amphibolites, around ∼370 Ma. The EMP monazite dating results for the Wuyishan terrain are quite different from the Yunkai massif where Triassic ages predominate, although the Wuyi-Yunkai metamorphic belt is often referred to as the same orogen in the Cathaysia Block.

Detailed age information of the Pingtan-Dongshan Metamorphic Belt in the coastal Cathaysia Block is important in understanding geodynamics of the Late Mesozoic South China continental margin. Geochronological determinations on monazite and zircon inclusions and zircon separates from five mica schists and two granites intruding schists are used to constrain the timing of metamorphism and sediment sources. Common ages of monazite and zircon inclusions within major constituents (quartz, muscovite, sillimanite and K-feldspar) in schists define a high temperature/low pressure metamorphic event at ~100 Ma. Along with zircon ages of granites (106 and 101 Ma), a Buchan type metamorphism is proposed regarding a heat source from the post-orogenic magmatism in the neighboring igneous province. Based on the age distribution patterns of discrete zircons, two groups of schist are distinguished by sources of sediments prior to metamorphism. One group has a simple age cluster (145–130 Ma) inferring proximal magmatic rocks in the Cathaysia Block. The other group shows a widespread age spectrum with two particular populations of ~1.8 Ga and ~190 Ma that are uncommon in the Cathaysia Block but comparable to schists in the Tailuko Metamorphic Belt of eastern Taiwan. This may suggest a general source between these two belts in which a now-concealed microcontinent would play a role. Such a new tectonic framework can account for the two provenances of sediments in schists of this belt, and its structural configuration is influenced by a high temperature regime caused by mantle upwelling as a reflection of slab rollback of the subducted Paleo-Pacific Plate during 110–90 Ma.

Geohistory of the Yunkai massif in South China Block is important in understanding the geodynamics for the build-up of this block during the Phanerozoic orogenies. To investigate this massif, we conduct EMP monazite and U-Pb zircon geochronological determinations on mineral inclusions and separate for seventeen samples in four groups, representing metamorphic rocks from core domain, the Gaozhou Complex (amphibolite facies, NE-striking) and the Yunkai Group (greenschist facies, NW-striking) of this massif and adjacent undeformed granites. Some EMP monazite ages are consistent with the NanoSIMS results. Monazite inclusions, mostly with long axis parallel to the cleavage of platy and elongated hosts, give distinguishable age results for NW- and NE-trending deformations at 244–236 Ma and 236–233 Ma, respectively. They also yield ages of 233–230 Ma for core domain gneissic granites and 232–229 Ma for undefomed granites. Combining U-Pb zircon ages of the same group, ~ 245 Ma and ~ 230 Ma are suggested to constrain the time of two phases of deformation. Aside from ubiquity of Triassic ages in studied rocks, ages of detrital monazite in the meta-sandstone match the major U-Pb zircon age clusters of the metamorphic rock that are largely concentrated at Neoproterozoic (1.0–0.9 Ga) and Early Paleozoic (444–431 Ma). Based on these geochronological data, Triassic is interpreted as representing the time for recrystallization of these host minerals on the Early Paleozoic protolith, and the also popular Neoproterozoic age is probably inherited. With this context, Yunkai massif is regarded as a strongly reactivated Triassic metamorphic terrain on an Early Paleozoic basement which had incorporated sediments with Neoproterozoic provenances. Triassic tectonic evolution of the Yunkai massif is suggested to have been controlled by converging geodynamics of the South China and Indochina Blocks as well as mafic magma emplacement related to the Emeishan large igneous province (E-LIP).

High arsenic abundance of 50-700μg/L in the groundwater from the Chianan Plain in southwestern Taiwan is a well-known environmental hazard. The groundwater-associated sediments, however, have not been geochemically characterized, thus hindering a comprehensive understanding of arsenic cycling in this region. In this study, samples collected from a 250m sediment core at the centre of the Chianan Plain were analyzed for arsenic and TOC concentrations (N=158), constituent minerals (N=25), major element abundances (N=105), and sequential arsenic extraction (N=23). The arsenic data show a prevalence of >10mg/kg with higher concentrations of 20-50mg/kg concentrated at 60-80 and 195-210m. Arsenic was extracted mainly as an adsorbate on clay minerals, as a co-precipitate in amorphous iron oxyhydroxide, and as a structural component in clay minerals. Since the sediments consist mainly of quartz, chlorite, and illite, the correlations between arsenic concentration and abundances of K2O and MgO pinpoint illite and chlorite as the major arsenic hosts. The arsenic-total iron correlation reflects the role of chlorite along with the contribution from amorphous iron oxyhydroxide as indicated by arsenic extraction data. Organic matter is not the dominant arsenic host for low TOC content, low arsenic abundance extracted from it, and a relatively low R(2) of the arsenic-TOC correlation. The major constituent minerals in the sediments are the same as those of the upriver metapelites, establishing a sink-source relationship. Composition data from two deep groundwater samples near the sediment core show Eh values and As(V)/As(III) ratios of reducing environments and high arsenic, K, Mg, and Fe contents necessary for deriving arsenic from sediments by desorption from clay and dissolution of iron oxyhydroxide. Therefore, groundwater arsenic was mainly derived from groundwater-associated sediments with limited contributions from other sources, such as mud volcanoes.

State-of-the-art GFP-based calcium indicators do not undergo efficient two-photon excitation at wavelengths above 1000 nm, for which inexpensive and powerful industrial femtosecond lasers are available. Here we report jYCaMP1, a yellow variant of jGCaMP7 that outperforms its parent in mice and flies at excitation wavelengths above 1000 nm and enables improved two-color calcium imaging with RFP-based indicators.

Cathaysia Block in South China had accreted tremendous amounts of Mesozoic magmatic rocks. Recent zircon U Pb age results revealed existence of some Early Jurassic gneissic granites (200–190 Ma) in the Pingtan-Dongshan Metamorphic Belt (PDMB), coastal SE China which corresponds one stage of magmatic quiescence in the rest part of East Cathaysia. To better understand Mesozoic thermal evolution of the PDMB, U Pb geochronology and Hf isotope composition of zircon separates (LA-ICPMS) and inclusions (NanoSIMS, age only) are examined for two granitic rocks and one meta-sandstone in Pingtan area (northern PDMB) and three granites in Matsu Islands further north. For Pingtan rocks, ages of discrete zircons are close to the Early Jurassic time in two stages (196 Ma and 173 Ma) yet all with predominantly positive ɛHf(t) values (−0.2 to 7.5), whereas zircon inclusions within rock-forming minerals yield a wide age span from Permo-Triassic to Early Cretaceous in six clusters, namely 270–206 Ma, 191–170 Ma, 168–151 Ma, 146–132 Ma, 126–119 Ma and 109–100 Ma that basically coincide the major Mesozoic thermal episodes in Cathaysia except the second cluster. For Matsu granites, discrete zircons exhibit Late Jurassic (162–158 Ma) and Early Cretaceous (137 Ma) ages with ɛHf(t) values of −9.1 to −1.6 and −4.9 to −0.8, respectively. Nevertheless, zircon inclusions show ages corresponding to Pingtan samples in the last four clusters. With reference to Mesozoic magmatic rock units in the neighboring Southeast China Magmatic Belt (SCMB), our data suggest irrelevance of Pingtan samples to the Cathaysia and linkage of off-shore Matsu granites to the PDMB. Noting that there are similarities of zircon ages and ɛHf(t) values between the granite-schist associations in Tananao Metamorphic Belt (TMB) of eastern Taiwan and Pingtan island of northern PDMB, these Early Jurassic granites were probably originated from a same source. Three consistent Early Cretaceous age clusters of zircon inclusions over the studied samples match two well-known magma prevailing episodes in the coastal SE China, with one tectonic episode (128–119 Ma) in the PDMB that is often invisible from the zircon separates remains unexplainable. In response to a plausible tectonic evolution, we support the earlier proposition for a now-concealed microcontinent that had impinged on Cathaysia around 125 Ma, but further suggest that it left Pingtan Island behind as a remnant fragment when drifted away at later time.

The Late Cretaceous to Early Cenozoic magmatism in the South China coastal area produced some amounts of rhyolitic rocks in two phases, which may be used to unravel the geohistory of the epilog of the paleo-Pacific plate subduction system. Essence of the Phase I rocks is the high temperature rhyolite (A-type)-trachydacite association in north Fujian (95–91 Ma) that was coeval with regional A-type granites. They succeeded the vast rhyolite–dacite–andesite (RDA) associations and I-type granitoids (113.5–96 Ma) and preceded the silicic-dominating rhyolite/basalt bimodal suites or monolithologic rhyolite in Zhejiang (89–86 Ma). Phase II rocks include (a) the RDA association or rhyolite alone in some drifted continental fragments nearby (83–56 Ma) and (b) the following rift-basin related rhyolite–trachyte/basalt bimodal suites in Guangdong and west Taiwan (56–38 Ma). The silicic volcanism, spatially changed from a NE–SW to the nearly E–W direction after 83 Ma, may reflect tectonic-driven eruptions occurred in the post-orogenic extensional (Phase I), resumed plate subducting (Phase IIa) and continental margin rifting (Phase IIb) stages. Rhyolitic rocks basically are shoshonitic to high-K calc-alkaline affinities while the Phase IIa RDA associations are mostly concentrated in the high-K to medium-K calc-alkaline series. All these rocks generally possess a continental arc character in tectonic discrimination diagrams, except shoshonitic rocks that have within-plate signatures. Based on the trace element and Nd–Pb isotope data, A-type rocks are suggested to have derived from mixing between trachydacitic (or syenitic) magmas and crustal melts of various sources under the high temperature condition (±metasomatism), and the succeeding silicic rocks are derivatives of the contaminated lithospheric mantle melts through crystal fractionation. On the other hand, Phase II silicic rocks are mainly the fractionation products of mafic magmas originated either from the lithospheric or the asthenospheric mantle. In reflection to such magmatotectonics with time, break-off of the subducted slab shortly before 113.5 Ma, change of the plate-moving direction between 86 and 83 Ma, and termination of plate movement probably at ∼56 Ma signify the epilog of the paleo-Pacific plate.

Zircon double dating technique for U-Pb and fission track (FT) ages is used to reassess the cooling conditions for the Pingtan-Dongshan Metamorphic Belt (PDMB). Three Cretaceous gneissic bodies from the Chinmen area and two dioritic plutons from the Zhangzhou Igneous Complex (ZIC) in two sides of the Changle-Nanao fault are studied. U-Pb dating results define the magma emplacement of gneisses at 144–134 Ma and dioritic rocks at 102–99 Ma, and FT dating results give ages of 96–86 Ma and ~87 Ma for corresponding samples. Combining 40Ar/39Ar mineral ages reported previously, the fast cooling curve (86 °C/Myr; 100–96 Ma) of ZIC plutons matches near-surface intrusives. However, those for deep-seated Chinmen gneisses are problematic as their resultant conditions are similar to ZIC samples. A recent concept favors the Early to Late Cretaceous tecto-magmatic evolution in the coastal SE China involving episodes of orogenic magmatism (147–130 Ma) and shallow magmatism under post-orogenic extension (110–85 Ma). As the Pingtan island in northern PDMB is considered as a remnant piece of colliding fragment, the cooling rate known for gneissic bodies in this island (35 °C/Myr; 130–120 Ma) can better represent the record of this collision. On the basis of these features, we advocate a magmatic quiescence at 130–120 Ma representing collision between PDMB and a concealed microcontinent which resulted in rapid uplift of this metamorphic belt. Cooling curves obtained for Chinmen gneisses are suggested to have further subjected to thermal reset by high temperature magmatism taking place during the post-orogenic stage.

In this study, the geochemical characteristics of mud volcanoes were investigated to seek their possible linkage with arsenic mobilization in the region. Among the mud volcanoes of southern Taiwan, the largest and well-preserved active mud volcanoes are situated in Wushanting (WST) and Hsiaokunshui (HKS). These two selected active mud volcanoes are exhaling mainly methane (CH4>95%) along with other gases like O2, CO2, CO, SO2, H2S, NO, and N2. The content of CH4 in the HKS active mud volcano is very close to that of the WST mud volcano. High Na+ and Cl- concentrations in mud liquids and mudstone deposits indicate their origin in a marine depositional source. However, a newly erupted active mud volcano in WST reflects the presence of a high level of SO4 2-. Significant variations (p≤0.05) in trace and transition element (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Cd and Ba) concentrations in the liquids and sediments of mud volcanoes are noticed at different eruption periods, suggesting different elemental compositions and release mechanisms in different locations. The weathering of micas as well as clay minerals seems to be responsible for the enrichment in trace metals in mud volcano sediments and fluids. Several trace elements (V, Cr, Mn, Fe, Co, Ni, and Zn) are strongly bound to the sediments, but concentrations of Cu, Se, and Sr are significantly higher in the fluids. The presence of higher As contents in the sediment of HKS was observed in contrast to its fluid. As a reducing agent, humic substances seem to play an important role in binding with trace elements and particularly As in the sediments. Fourier Transform Infrared (FTIR) spectra of humic substances from muds showed the presence of possible functional groups of primary and secondary amines, ureas, urethanes (amide) and silica.

The in-situ EMP (electron microprobe) monazite age dating performed directly in the polished sections, in addition to the conventional U–Pb zircon and EMP monazite age dating on grains from heavy mineral concentrates, has been applied to the granulite, charnockite and gneiss in the Gaozhou Complex of the Yunkai massif in South China. While the conventional dating systems all give Caledonian ages, the in-situ EMP monazite ages provide more information to reveal not only detailed age groups pertaining to the Caledonian orogeny but also traces of later thermal events overprinting these rocks. For granulites, although some monazites present zoning (concentric, patchy and complex) in the BSE images, no discernable age differences are observed. Resetting of the Th–U–Pb monazite dating system under the high temperature condition could be the reason. Ages of homogeneous monazite in garnet porphyroblast (ca. 440 Ma) of the garnet–cordierite granulite that match nicely with the U–Pb zircon ages are systematically older than those in the matrix (ca. 430 Ma). The same case of two age groups is also present in the orthopyroxene–biotite granulite as revealed by monazite inclusions in plagioclase and orthopyroxene and those in quartz, respectively. For charnockites, despite similar ages of ca. 430 Ma are given by monazite in biotite and zircon in the rock, significant younger ages are obtained from monazites with particular features. Relict monazites with a breakdown texture to form successive layers of apatite and allanite in the rim as well as those which are close to the biotite–chlorite microvein always show a similar age of ca. 230 Ma. Moreover, tiny monazites in close association with the garnetiferous corona mainly surrounding orthopyroxene give rise to another age group around 370 Ma. For gneissic rocks, monazites enclosed by quartz give 434 Ma and those setting in the chlorite–epidote microvein of a paragneiss yield 237 Ma, consistent with the U–Pb zircon core–rim age variations in the orthogneisses. With all these data, we suggest that the Gaozhou Complex is a Caledonian high-grade metamorphic terrain enduring initiation of granulites and paragneisses at the progressive metamorphism that predates intrusion of charnockites, formation of orthogneisses and modification of granulites and paragneisses at the peak time (436–432 Ma). It was then reactivated by the Hercynian and more vigorous Indosinian orogenies probably involving participation of fluid phases in the long course of retrogressive metamorphism during the early Phanerozoic. Such a tectonothermal evolution in the Yunkai massif may be comparable to the Kontum massif in central Vietnam.

Color image segmentation, an ill-posed problem, can be treated as a process of dividing a color image into some constituent regions and each region is homogeneous. In this study, a saliency-directed color image segmentation approach using ''simple'' modified particle swarm optimization (PSO) is proposed, in which both low-level features and high-level image semantics extracted from each color image are employed. To extract high-level image semantics from each color image, the visual attention saliency map for each color image is generated by three (color, intensity, and orientation) feature maps, which is used to guide region merging using ''simple'' modified PSO and a hybrid fitness function for color image segmentation. The proposed approach contains four stages, namely, color quantization, feature extraction, small region elimination, and region merging using ''simple'' modified PSO. Based on the experimental results obtained in this study, as compared with four comparison approaches, the proposed approach usually provides the better color image segmentation results.

The Darongshan granitic suite (~ 10,000 km2) consists of five major units (Taima, Nadong and Jiuzhou plutons, and Pubei and Darongshan batholiths) typical of peraluminous S-type granitoids containing abundant granulite inclusions in the Cathaysia block, South China. Six samples from these plutons and batholiths have been investigated using both LA-ICPMS U–Pb age dating on zircon cores and EMP U–Th–Pb chemical age dating on monazite cores and rims. LA-ICPMS zircon results give similar major age populations ranging between 260 ± 3 and 250 ± 3 Ma for all units, with apparent older age peaks concentrated at 1020, 800, 430 and 330 Ma. On the other hand, EMP monazite results yield younger ages of 231–229 Ma for Nadong, Taima, Pubei and Darongshan and 224 Ma for Jiuzhou samples, with older age groups of 264 Ma for Taima and 256–250 Ma for Pubei units. Since the older monazite ages are similar to the majority of zircon ages, the latter are considered as inherited ages. Further because such zircon ages are similar with the emplacement time of the Emeishan large igneous province in western South China, they likely reflect the timing of metamorphism for the included fragments of granulitic crusts that had been formed by invasion of the Emeishan plume. The younger monazite ages, as present for all plutons and batholiths in the entire Darongshan area, are taken as the formation age of the host granites. Combining U–Pb zircon and EMP monazite ages known for Permo-Triassic high temperature and high pressure metamorphic rocks and granites in the Indochina block (e.g., the Kannack Complex of the Kontum massif), it is suggested that the Indosinian thermal activity had set records over both the Indochina (plus Simao) and South China blocks in two main episodes, one is 260–250 Ma and the other is 231–229 Ma. One plausible explanation is that these two blocks were one united continent before the Emeishan plume activity and an opening was triggered by this plume at ~ 260 Ma. Due to forces of the approaching Sibumasu block, both the South China and Indochina blocks were amalgamated again at ~ 230 Ma. We, therefore, advocate that double subduction of the plume-triggered oceanic crusts in opposite directions is responsible for the generation of the Darongshan granitic suite in the South China block and its counterpart in the Indochina block.

Huayu, the only non-basalt islet in the Penghu Islands, consists mainly of andesite lavas intruded by some intermediate (dacite/granodiorite) and felsic (rhyolite/granite) dikes. The LA-ICPMS U–Pb zircon age determination yields 437 ± 13 Ma (n = 16, MSWD = 6.9) for the andesite lava and 63.3 ± 1.5 Ma (n = 7; MSWD = 2.9) for its potassic altered zone, and 58.7 ± 0.8 Ma (n = 14; MSWD = 2.5) for one rhyolite dike. The old and young groups of zircon show distinctive Hf isotope compositions: eHf(T) = −9 for ∼437 Ma zircons vs. eHf(T) = +9 to +6 and +9 to −1 for ∼63 Ma and ∼59 Ma zircons. On the other hand, Sr and Nd isotopic compositions of the andesite lava (ISr = 0.7034 and eNd(T) = +3.9 if T = 437 Ma) are more depleted than the alteration zone and rhyolite dike (ISr = 0.7051 and eNd(T) = −1.3 to −1.9). Decoupling of zircon eHf(T) and whole-rock eNd(T) values of the andesite lava rules out the possibility of 437 ± 13 Ma to be the eruption time. Alternatively, based on the similarity between the published zircon fission track ages (65 ± 3 Ma for the andesite lava and 61 ± 2 Ma for the rhyolite dike; [Yang, H.C., Chen, W.S., Huang, J.C., Wang Lee, C.M., 2008. Volcanic lithofacies of the Huayu Island. Bulletin of Central Geological Survey 21, 143–164 (in Chinese with English Abstract)]) and our U–Pb zircon ages of the altered andesite zone and rhyolite dike, the span of 65–63 Ma is suggested to be the formation time of Huayu andesites. Since Huayu is situated in a NE–SW trending high-magnetic anomaly belt which has been generally interpreted as a remnant magmatic terrain, these data, along with the geochemical results, provide insights of this belt as a split part of the Southeast Coast Magmatic Belt in which Huayu volcanics represent the younger arc volcanism comparable with those appeared in southern Fujian.

There is an ongoing debate concerning whether the vast Nanling Mountain granitoids of South China are the result of Jurassic paleo-Pacific subduction. We address this question by examining two Mesozoic basalt successions in South China, one parallel and the other oblique to the convergence boundary between the paleo-Pacific plate and South China continent. The geochemical characteristics of these basalts are used to constrain the influence of this presumed subduction system on mantle composition. 40Ar/39Ar age, major element and trace element abundances, and Sr, Nd and Pb isotope data indicate that the northeast-southwest trending basalts in the Southeast Coast Magmatic Belt that formed during 101–76 Ma exhibit arc-like signatures and are derived from subduction-modified mantle. However, the east–west trending basalt array extending from the Cathaysia Interior to the Cathaysia Folded Belt, which decreases in age from 175 to 98 Ma in an eastward direction, is characterized by lithosphere-modified OIB-like asthenosphere composition, except for a few younger rocks from Huichang which resemble Southeast Coast Magmatic Belt basalts. These results suggest that the Jurassic mantle beneath the Cathaysia Interior and the Cathaysia Folded Belt was rather homogeneous and undisturbed, and was not affected by the paleo-Pacific subduction system. Alternatively, post-orogenic (Indosinian) extension accompanied by mafic underplating may have been the cause of vast Jurassic granitic magmatism in South China.

The widespread Mesozoic granitoids in South China (∼135,300 km2) were emplaced in three main periods: Triassic (16% of the total surface area of Mesozoic granitoids), Jurassic (47%), and Cretaceous (37%). Though much study has been conducted on the most abundant Jurassic Nanling Mountains (NLM) granites, their rock affinities relative to the Triassic Darongshan (DRS) and Cretaceous Fuzhou–Zhangzhou Complex (FZC) granites which are typical S- and I-type, respectively, and the issue of their petrogenetic evolution is still the subject of much debate. In this study, we discuss the petrogenesis of NLM granites using apatite geochemistry combined with whole-rock geochemical and Sr–Nd isotope compositions. Sixteen apatite samples from six granite batholiths, one gabbro, and three syenite bodies in the NLM area were analyzed for their major and trace element abundances and compared with those collected from DRS (n = 7) and FZC (n = 6) granites. The apatite geochemistry reveals that Na, Si, S, Mn, Sr, U, Th concentrations and REE distribution patterns for apatites from DRS and FZC granites basically are similar to the S and I granite types of the Lachlan Fold Belt (Australia), whereas those from NLM granites have intermediate properties and cannot be correlated directly with these granite types. According to some indications set by the apatite geochemistry (e.g., lower U and higher Eu abundances), NLM apatites appear to have formed under oxidizing conditions. In addition, we further found that their REE distribution patterns are closely related to aluminum saturation index (ASI) and Nd isotope composition, rather than SiO2 content or degree of differentiation, of the host rock. The majority of apatites from NLM granites (ASI = 0.97–1.08 and eNd(T) = −8.8 to −11.6) display slightly right-inclined apatite REE patterns distinguishable from the typical S- and I-type. However, those from few granites with ASI > 1.1 and eNd(T) −6.6 and gabbro and syenite are similar to FZC apatites (strongly right-inclined). In light of Sr and Nd isotope compositions, magmas of NLM intrusives, except gabbro and syenite, and few granites with eNd(T) > −8, generally do not involve a mantle component. Instead, they fit with a melt derived largely from in situ melting or anatexis of the pre-Mesozoic (mainly Caledonian) granitic crust with subordinate pre-Yanshanian (mainly Indosinian) granitic crust. We suggest that an application, using combined whole-rock ASI and eNd(T) values, is as useful as the apatite geochemistry for recognizing possible sources for the NLM granites.

Rhyolite-dominating bimodal volcanic suites (rhyolite/basalt), mafic dikes and A-type granites distribute from N Zhejiang to S Fujian over 800 km in the Southeast Coast Magmatic Belt (SCMB) – the Late Yanshanian (LY) orogenic belt in SE China. Data of 40Ar/39Ar and K–Ar whole-rock ages and LA-ICPMS U–Pb zircon ages indicate that rhyolitic volcanism (101–72 Ma) is contemporaneous with the A-type granitic intrusions (100–90 Ma) and mafic dike injections (94–77 Ma). This time span is used to define the upper volcanic series in Zhejiang–Fujian areas. One striking feature of rhyolites in the SCMB is that many are strongly peraluminous (SP) and others, mostly restrict in Fujian, are peralkaline to mildly peraluminous (P-MP) and chemically resemble A-type granites. The SP character is unique among well-known large rhyolite provinces worldwide. Based on experimental works for a common thermal regime and inherited zircon age information, we suggest that SP and P-MP rhyolites represent low pressure melting of the felsic (quartzofeldspathic) granite (±metapelite) and the accompanied granodioritic, tonalitic and trondhjemitic member of the core complex assemblage, respectively, to account for the decreasing aluminosity. They could have also been contaminated by young igneous rocks, and ancient crust to a lesser degree, during ascent to the surface. Plate subduction and lithosphere extension processes, respectively, are numerically simulated for the magma generation of these rhyolites using the mafic underplating model. Results suggest that the most effective controlling factor to generate SP and associated P-MP (A-type) magmas during 95–80 Ma is thinning of the lithosphere thickness with a high exhumation rate. Under this circumstance, the core complex assemblage can be uplifted to lower level of the crust and match the constraint of experimental works.

CHIME ages of > 460 detrital monazites from beach sands from SE China (Chinmen Island) and W Taiwan were determined in order to deduce the major tectonothermal events affecting the coastal areas of SE China. Additional 360 monazites from estuarine sediments of the Minjiang River (eastern China), metamorphic rocks from Chinmen Island and sedimentary rocks from W Taiwan were also dated. Ages of the Chinmen beach monazites (245–80 Ma) reveal that they are derived from adjacent gneisses and mixed with sediment from the Jiulongjiang River (SE China). Some large, euhedral monazites contain older cores (∼220 Ma) and younger rims (137–124 Ma), demonstrating that overgrowth on inherited Indosinian grains occurred at the time of gneiss formation (137 Ma). Monazites of W Taiwan fall into two age groups, one in the Paleoproterozoic (1900–1650 Ma) and the other spanning the Phanerozoic (530–120 Ma). Based on similar ages of Phanerozoic monazites from the Minjiang River and W Taiwan, monazites of the latter group are inferred to be derived mainly from this river, hence the Paleoproterozoic monazites are most probably derived from Cathaysia basement exposed in the drainage basin of the Wuyishan (NW Fujian). Along with monazite ages of the two-mica schist, sediments from the uplifted Changle–Nanao shear zone (CNSZ) constitute only a minor component of deposits in W Taiwan. The age frequency distribution of Phanerozoic monazites from W Taiwan, which shows peaks at 450–430, 360–350, ∼275 and ∼245 Ma suggests the existence of Caledonian, Hercynian and Indosinian crust beneath the immense Yanshanian cover of the SE China coastal area.

Late Yanshanian magmatism in SE China includes three stages of thermal event induced by the interaction between the continental margin of Eurasia and the paleo-Pacific plate during the Cretaceous period. Products of syn-orogenic magmatism (130–110 Ma) include high-Al gabbros (HAG), and gneissic tonalite, trondhjemite and granodiorite (TTG), which intruded into the deep basement (18–24 km). Rocks of the post- and an-orogenic magmatism are shallow-level (6–8 km) I-type granitoids (110–99 Ma), and miarolitic A-type granites plus rhyolite-dominate bimodal volcanics (94–81 Ma), respectively. Geochemically, HAG and TTG belong to the medium-K calc-alkaline affinity with high Sr/Y, whereas other granitoids are mainly high-K calc-alkaline to shoshonitic rocks with low Sr/Y. Sr and Nd isotope compositions suggest different sources of HAG and TTG from other rocks. Progressive depletions of Ba, Sr, Eu and P from I- to A-type granites reflect partial melting of felsic granulites from hydrous to dry conditions, whereas high Sr/Y in HAG and TTG are compatible with dehydration melting of amphibolites. Tectonic models which accommodate HAG and TTG may involve thickening of the lithosphere to convert the pre-existing lower-crust basic rocks into amphibolites. It was followed by basaltic underplating which is attributed to delamination of the thickened lithosphere and led to triggering of crust melting under exten

Major and trace elements and Sm–Nd isotopic data are presented for metabasites that are present as lenses within Paleozoic metasediments in the Chenxing and Bangxi regions, central Hainan Island, Southeast (SE) China. Most metabasites are metamorphosed cumulated gabbroic rocks tholeiitic in nature, and characterized by varying degrees of depletion in Th, Nb, Ta and light rare earth elements (LREE). Moreover, they show high positive ∈Nd(T) values of approximately +7, similar to those of mid-ocean ridge basalts (MORB). A Sm–Nd isochron age of 333 ± 12 Ma obtained for the metabasites is interpreted as their crystallization age. The combined geochemical and Sm–Nd isotopic data suggest that the metabasites were generated by dynamic partial melting from a MORB-like mantle source in an oceanic regime. These rocks probably represent remnants of fragmented oceanic crust of the eastern part of Paleo-Tethys. They were obducted onto the continental crust as part of the ‘Shilu Melange’ in earliest Mesozoic time when southern Hainan (part of the Indochina block) collided with northern Hainan (part of South China). Alternatively, they could be formed in a volcanic rifted passive margin at the sea-floor spreading stage as part of MORB-like seaward-dipping reflector break-up packages.

Geochemical and Sr-Nd isotopic data are reported for late Paleogene potassic lamprophyres from western Yunnan, southeastern margin of the Tibetan Plateau. These lamprophyres are mostly ultrapotassic in composition with K2O/Na2O = 2.1 to 5.2, except for a few samples with shoshonitic affinity showing slightly lower K2O/Na2O = 1.6 to 1.7. They are characterized by high initial 87Sr/86Sr ratios of 0.70624 to 0.70924; negative eNd(T) values of -1.7 to -4.6; enrichment in large-ion lithophile elements, light rare-earth elements, and Pb; and depletion in high-field-strength elements, resembling those of high K/Ti and low-Ti potassic magmas formed in subduction-related settings. These lamprophyres were generated by partial melting of a metasomatized, phlogopite-bearing spinel harzburgite lithospheric mantle source, followed by crystal fractionation and varying degrees of crustal assimilation. Relatively constant incompatible trace element ratios, such as Rb/ Sr (˜0.2), Rb/Ba (˜0.1), La/Sm (˜5), Th/K (˜0.0003), a...

Geochemical and Sm–Nd isotopic results are reported for late Paleoproterozoic mafic amphibolites from SW Zhejiang and NW Fujian, parts of the Cathaysia Block of SE China. Two suites of contemporaneous amphibolites are distinct in their geochemical characteristics. Group 1 samples, from NW Fujian, have chemical compositions of transitional and alkali basalts, show LREE-enriched patterns and plot mainly in the field of within-plate basalt on a number of trace element discrimination diagrams. Group 2 rocks, from SW Zhejiang, have tholeiitic compositions and are characterized by flat to LREE-depleted patterns and fall into the MORB field. All the amphibolite samples have high eNd(T) values of +5.6 to +8.5 (T=1766±19 Ma). A positive correlation between eNd(T) and Nb/Th suggests possible mixing of a mantle-derived magma and a crustal component, with the least-contaminated samples having very high eNd(T) values (+8∼+8.5) and Nb/Th ratios of ∼13. The geochemical and isotopic characters and close temporal relationship of these two suites of amphibolites suggest that their magmatic precursors were likely formed in an environment similar to an ensialic rift developing into a proto-oceanic basin (e.g. the Gulf of Tadjoura). The exceptionally high eNd(T) values of up to +8.5 for some of the amphibolites suggest the presence of a time-integrated extremely depleted mantle source beneath Cathaysia during the Paleoproterozic.

A number of metamorphosed mafic rocks occurred within the Paleozoic strata in the Chenxing and Bangxi regions at the northern side of the Changjiang-Qionghai Fault in Central Hainan Island. These metamorphosed mafic rocks are tholeiites in chemistry. They are characterized by extreme depletion of Th, Nb, Ta and LREEs, resembling the depleted N-type mid-ocean ridge basalts (MORB). Field relations suggest that the protolith of the metamorphosed mafic rocks were likely formed in Paleozoic. These metamorphosed mafic rocks with N-type MORB geochemical features were probably the remnants of the Paleo-Tethys oceanic crust.

A NE-direction Mesozoic shoshonitic intrusive suite in SE Guangxi has been identified in terms of geological, petrological and geochemical investigations. The shoshonitic intrusives are characterized by enrichment of LILE, HFSE and LREE and no obvious Nb-Ta depletion, similar to those potassic rocks formed in within-plate and rifting environments. Unlike most shoshonitic rocks forming in arc settings, the SE Guangxi shoshonitic intrusives were likely generated during regional lithosphere extension induced by upwelling of asthenosphere mantle.

The Late Yanshanian Orogeny (130-90 Ma) encompasses an important Mesozoic magmatic event in the crustal evolution of SE China. Products of post-orogenic magmatism, widely distributed in the eastern part of Zhejiang and Fujian provinces known as the Southeast Coast Magmatic Belt (SCMB), are dominated by large amounts of slightly Nb and Ta depleted, high-K calc-alkaline granites (I-type) and small amounts of strongly Ba, Sr, Eu, Ti and P depleted, metaluminous granites (A-type). 40Ar/39Ar dating from amphiboles suggests that emplacement of A-type granites mostly postdates (94-90 Ma) the intrusion of voluminous I-type granitoids (110-99 Ma). Using the Al-in-amphibole geobarometer, I-type suites were estimated to have been emplaced at shallow depths (5-7 km). Along with the fact that A-type granites are phyric or miarolitic in texture, it can be concluded that all these post-orogenic suites in the SCMB belong to shallow intrusives. They have also undergone a rapid cooling (higher than 100°C/Ma at T > 300 °C) as indicated by the thermochronology of hornblende, biotite and K-feldspar; therefore, generation of A-type granites from I-type magmas through fractional crystallisation would be a difficult process. Alternatively, their geochemical characteristics are attributed to partial melting in the residual lower crust under an elevated geothermal environment. On the other hand, I-type magmas are considered to be middle-crust-derived melts largely modified with mantle-derived melts that had been depleted with Nb and Ta by earlier tectonic processes. Such a tectonic environment is explained by the underplating of basaltic magmas, most probably due to lithospheric delamination taking place at c. 110 Ma, which marks the beginning of the postorogenic episode in this area. Numerical modelling for a heat source provided by the underplating of basaltic magma supports such a proposition.

An approximately 20-m-thick alkali basalt flow on the Penghu Islands contains ∼20 cm thick, horizontally continuous (>50 m), vesicular layers separated by ∼1.5 m of massive basalt in its upper 8.5 m. The three layers contain ocelli-like "vesicles" filled with nepheline and igneous carbonate. They are coarse grained and enriched in incompatible elements relative to the massive basalt with which they form sharp contacts. These vesicular layers (segregation veins) formed when residual liquid in the underlying crystal mush was forced (gas filter pressing) or siphoned into three thermally induced horizontal cracks that opened successively in the advancing crystal mush of the flow's upper crust. Most vesicular layer trace elements can be modelled by residual melt extraction after 25–40% fractional crystallization of massive basalt underlying each layer. Sulphur, Cl, As, Zn, Pb, K, Na, Rb, and Sr show large concentration changes between the top, middle, and bottom layers, with each vesicular and underlying massive basalt forming a chemically distinct "pair." The large changes between layers are difficult to account for by crystal fractionation alone, because other incompatible elements (e.g., La, Sm, Yb, Zr, Nb) and the major elements change little. The association of these elements (S, Cl, etc.) with "fluids" in various geologic environments suggests that volatiles influenced differentiation, perhaps by moving alkali, alkaline earth, and chalcophile elements as magma-dissolved volatile complexes. Volatiles may have also led to large grain sizes in the segregation veins by lowering melt viscosities and raising diffusion rates. The chemical variability between layers indicates that a convection and concentration mechanism acted within the flow. The specific process cannot be determined, but different rates of vesicle plume rise (through the flow) and/or accumulation in the upper crust's crystal mush might account for the chemical pairing and extreme variations in Cl, S, As, and C. This study emphasizes the importance of sampling vesicular rocks in flows. It also suggests that volatiles play important physical and chemical roles in rapidly differentiating mafic magmas in processes decoupled from crystal fractionation.

Two crucial issues in the schedulability of real-time transactions in a distributed environment are the predictability of the execution times of the transactions and the coexistence of hard, firm and soft real-time transactions. To-date, there are very few research studies which have addressed these two very important issues. In the present study. the model of a distributed real-time database system has been implemented to evaluate a new transaction scheduling scheme to handle problems relating to the two issues. Simulation results indicated that using different scheduling algorithms for difference classes of real-time transaction can achieve significant improvement in the system performance.