Island Arc最新文献

{"title":"Correction to “Bringing the Submarine Mariana Arc and Backarc Basin to Life for Undergraduates and the Public”","authors":"","doi":"10.1111/iar.12538","DOIUrl":"https://doi.org/10.1111/iar.12538","url":null,"abstract":"<p>Stern, R. J. 2024. “Bringing the Submarine Mariana Arc and Backarc Basin to Life for Undergraduates and the Public.” <i>Island Arc</i> 33, no. 1: e12533. https://doi.org/10.1111/iar.12533.</p><p>Figures 3 and 4 captions should have been switched as shown below.</p><p>FIGURE 3(A) Front of a typical remotely operated vehicle (ROV). Note locations of key features: Lights, cameras (both still and video), manipulator arms, and sample baskets. Modified from NOAA ROV factsheet https://oceanexplorer.noaa.gov/edu/materials/rov-fact-sheet.pdf. (B) A typical ROV control room, from https://schmidtocean.org/cruise-log-post/technology-at-the-seafloor/.</p><p>FIGURE 4Schematic section through the upper 140 km of the Mariana convergent margen and subduction zone, showing the principal crustal and upper mantle components and their interactions. Note that the location of the “mantle wedge” (unlabeled) is that part of the mantle beneath the overriding plate and between the trench and the most distal part of the arc where subduction-related igneous or fluid activity is found. Modified after Stern (2002). MF, magmatic front.</p><p>We apologize for this error.</p>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/iar.12538","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142447708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent Efforts to Improve the Accuracy and Precision of Carbonate Clumped-Isotope Analysis","authors":"Kazuma Oikawa,&nbsp;Osamu Abe,&nbsp;Yasufumi Iryu","doi":"10.1111/iar.12537","DOIUrl":"https://doi.org/10.1111/iar.12537","url":null,"abstract":"<p>The carbonate clumped-isotope thermometer, a relatively recent innovation, is based on the strong relationship between ¹³C-¹⁸O bond abundance in carbonates and their formation temperature. It can measure temperatures solely based on the CO₂ extracted from carbonates and has attracted attention as it accurately reconstructs surface water temperatures on a geological timescale. However, at the time of development, there were many limitations in its application to paleoenvironmental reconstruction such as the large sample size (10 mg), the complicated organic contaminant removal process, and the lack of internationally recognized carbonate standards, and improvements in the measurement method were required. Here, we review the studies conducted since the thermometer development to improve the accuracy and precision of carbonate clumped-isotope analysis. Finally, we discuss advanced carbonate clumped-isotope analysis methods, including laser spectroscopy.</p>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/iar.12537","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"U–Pb Geochronology of the Baguio Area, a Major Mining District in Northern Luzon (Philippines)","authors":"Monika Walia,&nbsp;Rolando Pena,&nbsp;Ulrich Knittel","doi":"10.1111/iar.12535","DOIUrl":"https://doi.org/10.1111/iar.12535","url":null,"abstract":"<p>The Baguio District, located in northern Luzon (the Philippines), is one of the major gold and copper mining districts in the Philippines and SE Asia. U–Pb zircon ages for igneous rocks and for detrital zircons extracted from sediment samples of the principal formations of the Baguio District reveal major magmatic pulses at ca. 1, 3, 16, and 20 Ma. The oldest zircon dated in this study has an age of 27.3 ± 1.6 (2σ) indicating earlier activity which has, however, left only a small imprint on the zircon inventory of the sediments. The absence of older zircons suggests that northern Luzon formed as an intra-oceanic arc. Zircon Hf isotope data suggests that the magmas, from which the zircons crystallized, were derived from time-integrated highly depleted mantle sources, compatible with an intra-oceanic origin of the island. The results of the U–Pb dating of zircons mostly confirm previous estimates of the ages of the rock units. Mid-Miocene ages obtained for samples thought to represent the Pugo Formation, the lowermost unit, which is thought to be Cretaceous-Eocene in age, most likely date magmatic rocks that intruded the Pugo Formation.</p>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/iar.12535","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142435526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical Signatures of Igneous Zircon and Apatite: Generation of Archean TTGs in the Barberton Granitoid-Greenstone Terrain, South Africa","authors":"Shiho Miyake,&nbsp;Kazumasa Aoki,&nbsp;Tsuyoshi Komiya,&nbsp;Shogo Aoki,&nbsp;Mayuko Fukuyama,&nbsp;Masatsugu Ogasawara","doi":"10.1111/iar.12536","DOIUrl":"https://doi.org/10.1111/iar.12536","url":null,"abstract":"<div>\u0000 \u0000 <p>We performed isotopic and trace element analyses of zircons and apatites from the Inyoni, Batavia, and Badplaas tonalites, trondhjemites and granodiorites series (TTG) in the Barberton Granitoid-Greenstone Terrain (BGGT), South Africa using laser-ablation inductively-coupled plasma-mass spectrometry to investigate Archean tectono-magmatism. The U–Pb ages obtained from these minerals are consistent with previously reported ages ranging from ca. 3.28 to 3.23 Ga. The chondrite-normalized REE patterns of zircons and apatites enabled us to identify grains with primary information on TTG magmatism. Trace element characteristics, such as Sr/Y and Ti concentrations from primary grains, indicated that Inyoni TTG magmas coexisted with eclogite residue, whereas Badplaas and Batavia TTG magmas coexisted with garnet-amphibolite residue during the early formation stages. Furthermore, Lu–Hf isotope data, combined with the U/Yb-Nb/Yb data from zircons, suggested that the tectonic settings for TTG generation involved a subduction-type environment accompanied by crustal reworking. This implies that horizontal plate movement played a significant role in the TTG tectono-magmatism, and the subduction of old and cold plates facilitated slab melting under eclogite facies conditions, leading to TTG generation on the Archean Earth.</p>\u0000 </div>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142429020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrological and Geochemical Constraints on the Pelitic Hornfels of the Champaner Group, Western India: Implications for Its Origin and Evolution","authors":"Parita K. Gorania,&nbsp;Gayatri N. Akolkar,&nbsp;Aditya U. Joshi,&nbsp;Manoj A. Limaye,&nbsp;Mahendra K. Singh","doi":"10.1111/iar.12532","DOIUrl":"https://doi.org/10.1111/iar.12532","url":null,"abstract":"<p>The granitic intrusions emplaced into a terrane causes several textural, chemical and compositional changes in the host rock by wall-rock alteration and forms contact metamorphic rocks that is, hornfels. The low-grade metasedimentary rocks of the Champaner Group exposed as horse-shoe-shaped map pattern have envisaged several pulses of granitic intrusion with granitoid ages ranging from 2.5 to 0.95–0.93 Ga enclosing its most peripheries. However, it has been observed that the contact metamorphic signatures are most prominent on the eastern periphery of Champaner fading away towards the west slicing up the Champaner Group into outer, middle, and inner zone rocks. The present work is focused on the detailed study of inner zone pelitic hornfels by providing new constraints on field characteristics, reaction textures, mineral chemical compositional analyses, geochemical signatures, and P–T conditions. Three distinguished varieties of pelitic hornfels that is, biotite hornfels, andalusite-cordierite hornfels, and andalusite-sillimanite hornfels with increasing proximity to granitic intrusion respectively were identified. Based on the mesoscopic features, textural and phase relations, and mineral compositions, biotite, andalusite, cordierite, and sillimanite isograds were demarcated. The development of distinct mineral assemblages in different pelitic hornfels is correlated to the varying Al₂O₃, FeO, and MgO content in the bulk rock composition of the rocks and the geometry of the intruding felsic pluton (Godhra granite) beneath the Champaner supracrustals. The geochemical constraints suggest K-rich clay dominant shale protolith of post archean age comparable to Post-Archean Australian Shales (PAAS) deposited in an active continental margin tectonic setting. The increase in temperature gradient rather than pressure induced by 0.95–0.93 Ga “Godhra granitic” intrusion is considered to be a significant factor controlling the development of the observed progressive mineral assemblages. The P–T conditions constrained through P–T pseudosections built in a KFMASHTi model system suggest LP/HT metamorphism with P–T range from 200 to 350 MPa and 530°C–600°C respectively.</p>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/iar.12532","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bringing the Submarine Mariana Arc and Backarc Basin to Life for Undergraduates and the Public","authors":"Robert J. Stern","doi":"10.1111/iar.12533","DOIUrl":"https://doi.org/10.1111/iar.12533","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper aims to better teach about submarine arc and backarc basin volcanic and hydrothermal activity using the ~1400 km long Mariana convergent margin as an example. Four US National Oceanographic and Atmospheric Administration (NOAA) expeditions (2004–2016) equipped with a remotely operated vehicle (ROV) have discovered and explored many of submarine volcanoes and associated hydrothermal fields and generated many short (~1 min long) videos about them. Some of these videos would be very useful for teaching about these processes if they were organized and context provided, which is done here. Eighteen short videos about nine sites generated by NOAA are presented and discussed here. These are organized into three categories: volcanic eruptions, magmatic degassing, and hydrothermal activity. Volcanic eruption videos include two about glassy pillow lavas erupted in 2013–2015 and a rare example of a submarine eruption. Four videos about magmatic degassing include an example of sulfur produced by disproportionation of magmatic sulfur dioxide associated with a submarine eruption, two rare examples of molten sulfur lakes, and liquid carbon dioxide venting. Four videos about hydrothermal activity are provided. Suggestions for how this material might be used in the classroom are also given.</p>\u0000 </div>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/iar.12533","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142244959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cretaceous Fore-Arc Basin and Its Provenance in Sakhalin, Far East Russia: U-Pb Ages of Detrital Zircons From the Yezo Group","authors":"Tomohiko Sato,&nbsp;Yukio Isozaki,&nbsp;Yukiyasu Tsutsumi,&nbsp;Yasunari Shigeta,&nbsp;Kazuto Kodama,&nbsp;Takashi Hasegawa","doi":"10.1111/iar.12534","DOIUrl":"https://doi.org/10.1111/iar.12534","url":null,"abstract":"<div>\u0000 \u0000 <p>In order to reconstruct the pre-Japan Sea configuration of the Cretaceous arc-trench system, we measured U-Pb ages of detrital zircons in the five sandstone samples from the Yezo Group in Sakhalin using LA-ICP-MS. A sandstone sample from the lowermost horizon (Ai Formation) contains abundant Early Cretaceous (110–100 Ma) zircons with minor amounts of pre-Jurassic ones. Four sandstones from the uppermost (Krasnoyarka Formation) are enriched dominantly in Late Cretaceous (100–66 Ma) grains. The YC1σ ages of these samples are generally consistent with the previous fossil ages; nonetheless, a possible age extension of the Ai Fm up possibly into the Cenomanian was newly suggested. The stepwise younging in peak age of zircons according to the stratigraphy suggests the continuous replacement of arc granitoid exposures in the Cretaceous magmatic arc in the provenance likely developed on the continent side. This secular trend in zircon age spectra of the Yezo Group in Sakhalin is properly correlated with that in Hokkaido and also with that of coeval sandstones in southwest Japan, suggesting a monotonous sedimentation in the fore-arc basin of the Late Cretaceous arc-trench system developed along the Pacific margin, from Sakhalin to southwest Japan for ca. 2500 km in length. Its spatial dimension corresponds to that of the modern representative fore-arc basin in the Java-Sumatra region.</p>\u0000 </div>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142244968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical signatures of metapelites in the Highland Complex, Sri Lanka and Trivandrum Block, India: Implications for provenance, nature and tectonic setting of their source protoliths","authors":"A. M. M. G. I. U. B. Athauda,&nbsp;P. L. Dharmapriya,&nbsp;S. P. K. Malaviarachchi,&nbsp;K. Sajeev","doi":"10.1111/iar.12529","DOIUrl":"10.1111/iar.12529","url":null,"abstract":"<p>The investigation of whole-rock major and trace element geochemical data from metapelites, incorporating analyses from both previous studies and new localities within the Highland Complex (HC) of Sri Lanka and the Trivandrum Block of India (TB), aimed to discern the nature and tectonic setting of their provenance. Examination of chondritic REE distribution and K versus K/Rb diagrams suggests that the geochemistry of the studied metapelites closely resembles typical Post Archaean Australian Shale (PAAS), North American Shale Composite (NASC), and Upper Continental Crust (UCC), indicating minimal modification during high-grade metamorphism. Predominantly, the protoliths of the metasediments appear to be shales and greywackes derived from Proterozoic felsic to intermediate sources. Tectonic discrimination diagrams reveal that most metapelites correspond to active continental margins and continental island arcs. These geochemical characteristics suggest that the majority of studied metapelites in the HC and TB originate from felsic to intermediate sources, likely deposited within a continental arc setting. Subsequently, these sediments likely accreted in an accretionary prism and underwent metamorphism during continental-continental collision. The congruence in geochemical signatures between metapelites in the HC and TB, along with established tectonic, geochronological, petrological, mineralogical, and geophysical correlations, implies that precursor sediments of metasedimentary rocks were likely deposited within a laterally extensive Neoproterozoic sedimentary basin.</p>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141882510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the amount of uplift from the current elevation of strata at the Middle Miocene Climatic Optimum: A case study of Kibi Plateau in Southwest Japan","authors":"Yo-ichiro Otofuji","doi":"10.1111/iar.12531","DOIUrl":"10.1111/iar.12531","url":null,"abstract":"<p>The Middle Miocene Climatic Optimum (MMCO) formed shallow marine strata on continents and island arcs at ~15 Ma, and some of the MMCO strata later experienced uplift. The amount of uplift corresponded to sea level rise after the MMCO period, but ancient sea level could not be observed. This study uses a deductive approach to estimate the amount of uplift. The elevation of the youngest marine sedimentary layer of the MMCO strata approximates the sea level at the MMCO. The current elevation was reconstructed by adding the amount of denudation from the MMCO to the current elevation of the denuded MMCO strata at the outcrops, considering isostatic compensation. The amount of denudation since the MMCO period was estimated to be 180 m based on the global average denudation rate (Willenbring et al., 2013), and the estimated isostatic rebound was 153 m. By comparing the current, albeit virtual, elevation of the youngest marine sedimentary layer in the MMCO strata with sea level at the MMCO, the amount of uplift was estimated. For the MMCO sea level, a 66 m ice-free line was adopted. This method was applied to the Kibi Plateau in Southwest Japan, where the MMCO strata are distributed. The reliability of the denudation amount of 180 m for the MMCO strata was confirmed by paleo-water depths estimated using benthic foraminifera and mollusk fossils. The largest uplift of 504 ± 27 m occurred at the Jinseki-Kogen since 15 Ma. A positive correlation was observed between the amount of uplift and the current altitude of the Kibi Plateau. The Kibi Plateau's topography most likely evolved after the MMCO. It is concluded that a new perspective on estimating the uplift was obtained by taking denudation into account.</p>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141777071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subduction of the Paleo Pacific Plate at the southeast edge of the South China Block during the Early to Middle Jurassic: Sedimentary records from Fujian Province","authors":"Long Leng,&nbsp;Zhongjie Xu,&nbsp;Kunning Cui,&nbsp;Shiyao Gao,&nbsp;Ningchen Sun","doi":"10.1111/iar.12530","DOIUrl":"https://doi.org/10.1111/iar.12530","url":null,"abstract":"<p>During the Mesozoic, the tectonic evolution of the southeastern margin of the South China Block was mainly influenced by the subduction of the Palaeo-Pacific Plate. The sedimentary basins along the southeastern margin of the South China Block have preserved the sedimentary record of this process. In this paper, the sedimentary rocks of the Lishan Formation and Zhangping Formation in the Zhangping area of the southeastern margin of the South China Block are studied in terms of sedimentology, petrography, lithogeochemistry, U–Pb chronology of detrital zircon, and zircon trace elements. The study shows that the detrital zircon U–Pb age of the Lishan Formation is 2965–202 Ma, with two major age groups: 253–220 Ma and 1925–1799 Ma; the detrital zircon U–Pb age of the Zhangping Formation is 2587–190 Ma, with two major age groups: 246–234 Ma and 1929–1861 Ma; the ancient sediments in the samples are affected by recycle, and the Early Jurassic source area in the study area is an acidic magma zone, while the Middle Jurassic source area is located in a moderately acidic magma zone and recycle body; the Early Jurassic Lishan Formation and Middle Jurassic Zhangping Formation are mainly derived from the Wuyi Massif. In the upper section of the Lishan Formation, the secondary age groups of ca.448 and ca.773 Ma occur, and the detrital zircons in this section are mainly from the Jiangnan orogenic belt. The ongoing subduction of the Paleo-Pacific Plate led to the formation of diverse back-arc basins within the region; during the Early Jurassic, it was a back-arc compressional basin, transitioning into a back-arc extensional basin during the Middle Jurassic.</p>","PeriodicalId":14791,"journal":{"name":"Island Arc","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141584005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}