International Journal of Earth Sciences最新文献

{"title":"Black shale deposition during the Paleocene–Eocene thermal maximum: shale-gas potential of the Patala Formation, Himalayan fold-and-thrust belt, Pakistan (eastern Tethys)","authors":"Nasar Khan, Ralf Littke, Gert Jan Weltje, Rudy Swennen","doi":"10.1007/s00531-024-02436-4","DOIUrl":"https://doi.org/10.1007/s00531-024-02436-4","url":null,"abstract":"<p>This study focuses on the implications of a global hyperthermal event, the Paleocene–Eocene Thermal Maximum (PETM) for the origin, preservation and maturation of organic matter (OM) in the Late Paleocene Patala Formation, Himalayan fold-and-thrust belt, Pakistan. The OM present in the full array of lithofacies of the Patala Formation is characterized by petrographic (vitrinite reflectance) and geochemical techniques (total organic carbon (TOC), total organic nitrogen (TON), Rock-Eval pyrolysis and stable C and N isotopes). These analyses record deposition of the formation in a Late Paleocene shallow marine shelf environment. The organic geochemical proxies indicate the presence of Type III mixed with subordinate Type II kerogen as well as thermally immature to early mature source rocks. OM is derived both from terrestrial and marine sources. Rather high TOC (&gt; 2 wt.%) and a negative carbon isotope excursion (CIE) reveal that the prevalence of anoxic conditions, at least for short periods, enhanced OM preservation. The quantity and quality of OM, as well as the thickness and thermal maturity of the Patala Formation, make it a potential target for shale-gas exploration. During PETM, the extensive biological activity and addition of organic carbon into shallow marine eastern Tethyan settings provided precursor materials for hydrocarbon source rocks and shale-gas generation within the Patala Formation. The high organic influx and suboxic to anoxic conditions during PETM also facilitated OM preservation within the formation. Thus, the transient global warming PETM event significantly contributed to the OM accumulation and its preservation, which implies the suitability of such source rocks for shale-gas exploration within the Potwar Basin (Pakistan) and similar basins in neighboring areas.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"24 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Permian thermally-induced shear of the Cossato-Mergozzo-Brissago shear zone in the W-Southalpine basement, Italy: new petrological, geochemical and U–Pb geochronological constraints from the amphibolite-facies units of the Strona Ceneri Border Zone","authors":"F. Arboit, A. Decarlis, S. Ferrando, A. Maffeis, S. De Bernardi, A. Ceriani","doi":"10.1007/s00531-024-02435-5","DOIUrl":"https://doi.org/10.1007/s00531-024-02435-5","url":null,"abstract":"<p>The onset of the Cossato-Mergozzo-Brissago shear zone within the Strona Ceneri Border Zone in the W-Southalpine basement (Italy) and its role in the collapse of the Variscan crust have been the subject of considerable controversy. A set of new petrographic, geochemical and geochronological data from a suite of syn-kinematic migmatitic paragneiss and amphibolites in between the upper and lower crustal sections of the W-Southalpine basement provide new evidence on the thermo-mechanical role played by the middle crust in the evolution of the Permian Southalpine basement. The petrological investigation of these amphibolite-facies rocks and U–Pb ages from monazite crystals, occurring in distinct microstructural positions, provide new <i>P–T-t</i> constraints on the late-Paleozoic tectono-thermal evolution of the Variscan middle crust. The SCBZ units recorded tectonic events from a possible Early Silurian Cenerian (ca. 440 Ma) overprint onto the proto-sedimentary units of the Southalpine basement to the Mid-Permian (ca. 285 Ma) syn-kinematic partial melting event developed close to the CMB shear zone. Phase equilibria modeling is used to constrain the metamorphic conditions recorded by this section of the Variscan basement. Pressure–temperature (<i>P–T</i>) isochemical phase diagrams show that, after the ca. 330 Ma Variscan metamorphic peak at <i>P</i> ≅ 4 kbar and <i>T</i> &lt; 630 °C, the SCBZ paragneiss experienced isobaric heating up to 700–720 °C at ca. 285 Ma, which led to the formation of a syn-kinematic partial melting event coeval to the emplacement of the Mafic Complex in the lower Ivrea-Verbano Zone. These new geochronological and petrological constraints on the SCBZ paragneiss seem to corroborate the hypothesis that the transition from the stage of mature Variscan orogen to the stage of its collapse developed in the Permian, at ca. 285 Ma. Thus, we argue that the orogenic collapse was probably driven by the rheological weakening of the mid-crustal SCBZ units induced by their syn-tectonic partial melting and, ultimately, by the coeval thermal perturbation of the crust due to the intrusion of the mafic igneous suite at the crust-mantle boundary.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"31 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141514179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinematic reconstruction of the Alpine Tethys and surrounding Mesozoic rifted margins","authors":"Gianluca Frasca, Gianreto Manatschal, Pauline Chenin","doi":"10.1007/s00531-024-02407-9","DOIUrl":"https://doi.org/10.1007/s00531-024-02407-9","url":null,"abstract":"<p>In plate kinematic reconstructions, the restoration of rifted margins and their fossil equivalents exposed in orogens remains challenging. Tight fit reconstructions rely on the mapping of margins rift domains, their restoration to their pre-rift crustal thickness, and the removal of the oceanic and exhumed mantle domains. At present-day margins, high-resolution wide-angle seismic imaging allows mapping and measurement of rift domains; however, restoring fossil margins is trickier because they are largely overprinted and partially lost during convergence. Here, we present a new kinematic model for the Mesozoic rifting along the Tethys–Atlantic junction, which relies on two assumptions: (1) the width of the fossil Alpine Tethys rift domains was comparable to that of their present-day analogs, and (2) the necking zones of the former tectonic plates can be mapped, dated and used as kinematic markers. This reproducible workflow allows us, for the first time, to restore the rifted margins of the Alpine Tethys. Our reconstruction shows: (1) a westward propagation of extension through the Ionian, Alpine Tethys and Pyrenean rift systems from the Triassic to the Cretaceous, (2) the segmentation of the Mesozoic Tethyan rifted margins by strike-slip corridors, (3) the opening of an oceanic gateway at 165 Ma as mantle was exhumed along the entire Alpine Tethys and (4) the subdivision of the Mesozoic oceanic domain into compartments that were later consumed during subduction. This new model is supported by published data from the Alps, the Ionian Sea, the Pyrenees and the southern North Atlantic.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"5 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141514180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Slope-specific lateritization of garnet–sillimanite–gneiss cuestas in Matale area, Sri Lanka","authors":"W. K. G. V. Weligepola, D. M. S. N. Dissanayake, M. M. M. G. P. G. Mantilaka, H. M. T. G. A. Pitawala","doi":"10.1007/s00531-024-02421-x","DOIUrl":"https://doi.org/10.1007/s00531-024-02421-x","url":null,"abstract":"<p>This study investigates the uncommon formation of laterite from garnet–sillimanite–gneiss (grt-sil-gn) in the Matale area, a hilly region of Sri Lanka. Geographically, laterites typically form in lowland wet zone of the country, but this research explores their genesis in a unique, less-studied hilly environment. Employing a comprehensive approach combining field observations, petrographic studies, and chemical mapping, we elucidate the contrasting mechanisms of lateritization on the dip slope and scarp slope of a cuesta landform. Our findings reveal a significant influence of weathering conditions and supergene processes on laterite formation. Dip slopes experience intense supergene activity due to deeper groundwater, promoting downward fluid flow and mineral dissolution. Conversely, scarp slopes exhibit isovolumetric leaching with reduced infiltration and enhanced fluid interaction, leading to lateritization along fractures in partially weathered grt-sil-gn. Intense supergene processes on the dip slopes involve downward fluid migration and mineral dissolution, aided by a deep groundwater table. In contrast, scarp slopes exhibit laterite formation through isovolumetric leaching in areas with reduced water infiltration and heightened fluid interaction. Evidence of lateritization includes the formation of gibbsite, hematite, or goethite, attributed to fluctuating oxic and anoxic conditions caused by fluid variations. Additionally, kaolinite patches emerged on the exterior of fully altered garnet, resulting from the weathering products and leachates of quartz, sillimanite, and feldspar. This research emphasizes the critical role of external factors, such as weathering and supergene processes, alongside parent rock composition, in influencing laterite formation. It significantly advances our understanding of lateritization in grt-sil-gn, particularly in hilly areas with lower rainfall compared to usual laterite formation zones.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"89 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Initiation of the Unazuki Belt, Southwest Japan, during the Carboniferous as an island arc system along the North China Craton","authors":"Chang Whan Oh, Kenta Kawaguchi, Bo Young Lee, Seung Hwan Lee, Takeshi Imayama","doi":"10.1007/s00531-024-02422-w","DOIUrl":"https://doi.org/10.1007/s00531-024-02422-w","url":null,"abstract":"<p>The Unazuki Belt, Southwest Japan, is a part of the Hida Belt, which is characterized as a plutono-metamorphic complex with a continental affinity formed between the late Paleozoic and early Mesozoic. The Unazuki Belt is known to be an important tectonic unit for the tectonic correlation between the proto-Japan and East Asian continents as it records Permo–Triassic tectono-thermal events, however, comprehensive chronology of the Unazuki Belt including the timing of the initiation of this Belt is yet unclear. The present study reveals certain Carboniferous magmatic and sedimentation events from the Unazuki Belt and their tectonic implications for the first time as follows. Zircon U–Pb age dating results and whole-rock geochemical compositions show that the protoliths of metagranite and metatrachyandesite in the Unazuki Belt formed at 328.2 ± 4.4 Ma and 332.8 ± 2.2 Ma, respectively, in an arc tectonic setting. Most metasedimentary rocks of the Unazuki Belt have the youngest detrital zircon grains of ~ 300 Ma with the Carboniferous single cluster at ~ 340–300 Ma without any Pre-360 Ma detrital zircon grains. However, one metasedimentary rock with Precambrian detrital zircons (~ 20%) has the youngest detrital zircon age of ~ 252 Ma, and ~ 66% of detrital zircons show a Permian age. Most of the ε_Hf(t) values of zircon grains from all the studied Unazuki Belt samples, including the metasedimentary and metaigneous rocks with Carboniferous ages (~ 360–300 Ma) are positive (+ 6– + 18), whereas those of the zircon grains with Permian ages (~ 280–260 Ma) show wide variations between + 16 and -23. The whole-rock geochemical compositions of the ~ 300 Ma metasedimentary rocks of the Unazuki Belt show an island arc tectonic setting, whereas those of ~ 252 Ma metasedimentary rock have a continental arc affinity. These new data suggest that (1) igneous and sedimentary rocks in the Unazuki Belt formed in the island arc tectonic setting separated from the margin of continental crust during the Carboniferous but shifted to the continental arc tectonic setting during the latest Permian, (2) the collision between the island arc and continental arc may have caused the intermediate-<i>P/T</i> metamorphism during the Permian in the Unazuki Belt. The Carboniferous island arc tectonic setting in the Unazuki Belt indicates that the Hida Belt, including the Unazuki Belt, formed not at the margin of the South China Craton where Carboniferous subduction is absent but on the continuous subduction zone located along the eastern margin of the North China Craton, including the eastern margin of the northern Korean Peninsula where Carboniferous subduction occurred.</p><h3 data-test=\"abstract-sub-heading\">Graphical Abstract</h3>\u0000","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"12 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140931319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gondwana sedimentary rocks of Andigama Basin, Sri Lanka: unraveling weathering dynamics, tectonic setting, and paleoclimate","authors":"B. M. Gunathilake, D. T. Jayawardana, A. S. Ratnayake, A. M. N. M. Adikaram","doi":"10.1007/s00531-024-02423-9","DOIUrl":"https://doi.org/10.1007/s00531-024-02423-9","url":null,"abstract":"<p>The Andigama Basin is a pre-rift Gondwana sedimentary basin containing Late Jurassic to Early Cretaceous calcareous sandstones and carbonaceous shales of varying thickness. This study aims to reconstruct the weathering, tectonic setting, and paleoenvironment of East Gondwanaland using a 90 m deep drill core. Whole-rock geochemistry and elemental analysis were carried out using X-ray fluorescence spectrometry and CHNS/O elemental analyzer, respectively. Lithological changes in the borehole core reflect diverse hydrodynamic conditions. X-ray diffraction patterns indicate a significantly high content of quartz and kaolinite peaks. Scanning electron microscope images suggest that quartz, carbonate, and aluminosilicate dominant detrital particles and chemical residues enhanced the cementation by reducing the porosity and permeability of sealing interfaces. Major oxide and trace element concentrations are approximately similar to the Upper Continental Crust values. High Chemical Index of Alteration, Plagioclase Index of Alteration, Index of Compositional Variability, and high content of kaolinite peaks reflect intense chemical weathering, suggesting a hot and humid climate during the Late Jurassic–Early Cretaceous periods. The calculated paleo-land surface temperature (24.7 ± 5 °C) and mean annual precipitation (1120 mm) values are also consistent with the interpretation of weathering indices and global oxygen isotopic studies. Provenance and tectonic setting discrimination diagrams suggest the deposition of quartzose and mafic igneous sources under the passive margin stage. In addition, elemental analysis indicates a nutrient-rich (average total organic carbon = 4.67 ± 1.04 wt. % and total nitrogen = 3.13 ± 3.39 wt. %) and oxic to oxygen-poor reducing (average total sulfur = 2.13 ± 1.43 wt. %) swamp environment. Consequently, the Late Jurassic–Early Cretaceous climate was simulated as a prominent deglaciation/hot and humid climate in the Gondwana supercontinent, based on calculated paleo-land surface temperatures and mean annual precipitation.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"26 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140931632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magma recharge in persistently active basaltic–andesite systems and its geohazards implications: the case of Villarrica volcano, Chile","authors":"J. A. Cortés, R. Gertisser, E. S. Calder","doi":"10.1007/s00531-024-02414-w","DOIUrl":"https://doi.org/10.1007/s00531-024-02414-w","url":null,"abstract":"<p>We report whole-rock chemistry, mineral chemistry, and volatile content from Villarrica volcano’s major recent paroxysms and background activity. Composition of the volcanic products are basalt to basaltic andesite with whole-rock SiO₂ content between 50 and 56 wt%, and a mineralogy dominated by olivine (Fo_71-80), clinopyroxene (Mg# ~ 50) and plagioclase (An_60–80). Volatile contents in melt inclusions are up to 1.5 wt% H₂O, 500 ppm CO₂, 1230 ppm sulfur and 580 ppm chlorine. Regardless of the type of activity, there are no substantial variations in whole-rock composition or the volatile content when the activity switches from background activity to a major paroxysm, strongly suggesting that this shift does not just depend on the arrival of new magma in the shallow magmatic system. Geothermobarometry constrains crystallization of the major mineral phases at various depths between 3 and 12.7 km, suggesting that degassing of a volatile-rich recharge magma occurs deeper than 12 km, producing efficient mixing throughout the whole system, and sustaining the lava lake activity in Villarrica’s summit crater. The occurrence of a permanent lava lake also suggests that the magma recharge must be close to continuous and therefore sudden changes between background and paroxysmal volcanic activity are likely controlled by relatively small changes in the rate of recharge and/or the volatile release rate in the magmatic system. This has important implications for the understanding of eruption triggers and the forecasting of volcanic eruptions.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"12 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140931243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate cyclicity-controlled recurrent bottom-water ventilation events in the aftermath of the Toarcian Oceanic Anoxic Event: the Jenkyns Event","authors":"Lorenz Schwark, Wolfgang Ruebsam","doi":"10.1007/s00531-024-02417-7","DOIUrl":"https://doi.org/10.1007/s00531-024-02417-7","url":null,"abstract":"<p>Environmental perturbations of the Toarcian Anoxic Event and its associated carbon isotope excursion (CIE) occurred in a cyclic fashion indicating an orbital control mechanism. Sedimentary strata of the <i>E. elegantulum</i> ammonite subzone in the Lorraine Sub-basin, Luxembourg, exhibit eight sedimentary cycles, most of which postdate the CIE, implying that its termination did not coincide with a full recovery from environmental stress. Sea-level and temperature fluctuations of the Toarcian crisis were linked to a cryosphere demise in the Northern Hemisphere, which modulated stadial versus interstadial phases on the orbital 100 ka eccentricity frequency band. Upon stadial phases, enhanced wind strength in combination with lowered sea level disrupted stratified shelf waters and shifted the storm wave base close to the sea floor. Ventilation of bottom waters interrupted accumulation of laminated and organic-rich black shales, but formed organic-lean and non-laminated gray claystones enriched in terrigenous wax lipids and spores provided via aeolian transport from the hinterland due to the enhanced wind strength. Wind systems are assumed to have been driven by high pressure differences between the cryosphere in the North of the Tethyan shelf and the warmer costal lowland. This distinguishes the atmospheric turbulences after the CIE from the postulated intensification of the cyclones that accompanied the rapid warming at the beginning of the CIE. The deep-water ventilation event following the CIE in the Lorraine Sub-basin was accompanied by a parallel evolution in the SW German Basin, indicating a supraregional driving mechanism in paleobathymetric sub-basins susceptible to lowering of storm wave base. In sub-basins with greater water depth on the NW-Tethyan shelf, post-CIE orbitally driven atmospheric turbulences had a minor or no effect on water column stratification and deposition of organic-rich laminated black shales persisted.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"16 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140931242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zircon trace element fingerprint of changing tectonic regimes in Permian rhyolites from the Central European Lowlands","authors":"Słodczyk Elżbieta, Pietranik Anna, Repstock Alexander, Przybyło Arkadiusz, Glynn Sarah, Lukács Réka","doi":"10.1007/s00531-024-02419-5","DOIUrl":"https://doi.org/10.1007/s00531-024-02419-5","url":null,"abstract":"<p>The late Carboniferous/early Permian post-collisional rhyolites (305–285 Ma) that formed in Central Europe have generally similar whole rock compositions to that of older Late-Variscan rhyolites (330–310 Ma). However, data compilation combining zircon age with the chemical composition of rhyolites from 20 units shows a trend of increasing zircon saturation temperature with decreasing age. This trend is particularly well identified in rhyolites from the Central European Lowlands (CEL)—consisting of the NE German and NW Polish Basin—and also correlates their location with the zircon saturation temperature increasing from SE to NW from 750°C to 850°C. We infer that these higher temperatures of zircon saturation reflect a contemporaneous change in the tectonic setting from collisional to divergent, reflecting the onset of the Central European continental rifting. This interpretation is further corroborated by the trace element compositions of the CEL zircons, which resembles zircon crystallized in a divergent setting. Interestingly, the zircon formed globally in this type of setting is chemically diverse, especially considering uranium concentration. For example, zircon from locations dominated by mafic magma fractionation, such as rhyolites from Iceland, have low U concentrations and low U/Yb ratios. On the other hand, zircon formed in rhyolites in rifted margins, like western North America, tends to have much higher U and U/Yb ratios. Such high concentrations are not observed in zircon from the CEL, suggesting that the mantle input could be higher and residence times within continental crust shorter than those for rhyolites from the Cenozoic western USA. This may, in turn, suggest that the region might have been affected by a hot spot, similar to that responsible for rhyolite formation of the Snake River Plain.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"23 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140931419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crustal dynamics prediction and characterization for the Yishu fault zone based on slip susceptibility analysis","authors":"Guiyun Gao, Pu Wang, Chenghu Wang, Chengwei Yang","doi":"10.1007/s00531-024-02424-8","DOIUrl":"https://doi.org/10.1007/s00531-024-02424-8","url":null,"abstract":"<p>We estimate the slip susceptibility of faults in the Yishu fault zone using a slip tendency analysis based on coupled tectonic stress profiles. Studying in situ stress data and focal mechanism solution data collected in this area over more than 30 years, we construct the stress profiles of the study area using the coupling analysis method for deep and shallow stress data. Subsequently, the susceptibility of faults to slip is comprehensively evaluated based on various stress indicators and other related factors. Our results show that the frictional characteristic index <i>μ</i>_m is low in the deep and shallow crust of the Yishu fault zone, indicating a low degree of overall stress accumulation. A comprehensive evaluation of the susceptibility of faults to slip based on five typical factors (<i>μ</i>_m, horizontal-to-vertical stress ratio <i>K</i>, angle between the <i>P</i> axis and fault plane <i>θ</i>, S-wave velocity, and seismic density) indicates that the overall seismic risk in the central part of the Yishu fault zone is low, while the northwestern Yishu fault zone exhibits high seismic risk. Furthermore, the southeastern part of the Yishu fault zone reflects the transition from medium- to low-seismic risk. These results provide geomechanical and fault mechanics evidence for evaluating the regional crustal dynamics of the Yishu fault zone.</p><h3 data-test=\"abstract-sub-heading\">Graphical abstract</h3>\u0000","PeriodicalId":13845,"journal":{"name":"International Journal of Earth Sciences","volume":"81 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}