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The most striking Lincang granitic batholith widely distributed in the Sanjiang Paleo-Tethys Orogen provides us a crucial window to understand the subduction, consumption, and associated geodynamic mechanism of the Paleo-Tethys Ocean during the late Paleozoic to early Mesozoic. In this study, we carry out an integrated study of petrology, zircon U-Pb geochronology, whole-rock major and trace elements, and in situ zircon Hf isotope of the Late Triassic granitic rocks from the Lincang granitic batholith, with the aim of investigating their geochronological framework, spatio-temporal variations, genetic mechanism, and tectonic significance. The granitic rocks presented in this study consist of granodiorite and monzogranite, with minor syenogranite. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb dating of these granitic rocks yield crystallization ages of 237.6–209.0 Ma, indicating multi-stage granitic magmatic activities during the Late Triassic. Geochemical analyses show that these granitic rocks belong to medium-K calc-alkaline and shoshonite series, and have metaluminous to peraluminous characteristics and low whole-rock zircon saturation temperature (726–834°C). The Late Triassic granitic rocks show transitional characteristics and originate from different magma sources, indicative of transitional I-type and S-type granite affinities. The 237.6 Ma gneissic granodiorites belong to I-type granite and have typical continental arc granites of enrichments in large ion lithophile elements (Rb, K, Pb, and Th) and light rare earth elements (LREEs), and depletion in high field strength elements (Nb, Ta, Ba, Ti, and P) and heavy rare earth elements (HREEs), with parental magma derived from garnet amphibolite facies lower crust. Whereas the 222.7–209.0 Ma granitic rocks have S-type granite affinities with psammitic source. The transitional geochemical characteristics led us to favour that syn-collisional stage in response to final closure of the Paleo-Tethys Ocean in Southwestern Yunnan lasted at least until 237.6 Ma. Subsequent extensional mechanism and associated asthenosphere upwelling after final closure of the Paleo-Tethys Ocean induce large-scale partial melting of the middle-lower crust, resulting in voluminous generation of S-type and A-type granitic rocks and associated volcanic rocks in Southwestern Yunnan. [ABSTRACT FROM AUTHOR]

The southward extension of the Bangong-Nujiang Suture and the late Mesozoic tectonic affinity of the Tengchong Block have been subject to debate, and the Early Cretaceous magmatism in the eastern Tengchong Block provides a crucial window to address these issues. This paper reports comprehensive petrographic, geochemical, geochronological, and isotopic data of Early Cretaceous granitic rocks from the eastern Tengchong Block. Results show that these granitic rocks consist of monzogranites and granodiorites, with zircon U-Pb ages of 120.4–113.9 Ma. These granitic rocks are characterized by enrichments in large ion lithophile elements (e.g. Rb, U, K) and light rare earth elements, but depleted in high field strength elements (e.g. Nb, Ta, P, Ti), and have negative apatite εNd(t) values (−10.4 to −6.7) and negative zircon εHf(t) values (−11.7 to −1.2). The molar [Al2O3/(CaO + K2O + Na2O)] (A/CNK) values and whole-rock zircon saturated temperatures of the studied monzogranites of 1.04–1.09 and 714–799°C, respectively, indicate that they have I-type granite affinity. The presence of biotite indicative of I-type granite and the observation that P2O5 decrease with increasing SiO2 further indicated that the monzogranites have affinities of I-type granites. The petrography, geochemical and isotopic signatures of the studied monzogranites indicate that they originated from partial melting of mafic lower crustal rocks. The Na-rich granodiorites have elevated Na2O/K2O ratios and Na2O contents of 1.19–2.04 and 3.12–3.47 wt.%, respectively. These granodiorites also have relatively high Mg# values and the transition metal element Cr of 53.3–54.5 and up to 100 ppm, respectively. According to these isotopic and geochemical features and the occurrence of magnesiohornblende, we propose that the Na-rich granodiorites were derived from partial melting of ancient basaltic lower crust, with certain inputs of mantle materials in the magma source. Considering these results as well as published data, we finally propose that the Tengchong Block was likely the southeastern extension of the Lhasa Block and that these Early Cretaceous granitic rocks were formed in the setting of the volcanic arc due to westward subduction of the Bangong-Nujiang Tethys oceanic lithosphere beneath the Tengchong Block. [ABSTRACT FROM AUTHOR]

In non-coherent impulse system,an acquisition scheme using negative-slope saw-tooth-waveform matching was proposed.The scheme obtained the sub-optimal estimation performance by utilizing the characteristic of multipath profile.In the proposed scheme,the slope of saw-tooth waveform was analyzed to achieve unbiased estimation in NLOS environment,and the theoretical solution of mean-absolute error（MAE） was derived.Simulations verify the outstanding performance of this scheme in NLOS and low signal-to-noise ratio（SNR） environment.

Chronological and geochemical studies of adakites and adakitic rocks are important in understanding the tectonic evolution and geodynamic processes. We present new zircon U–Pb ages, Hf isotope, and geochemical analyses of adakitic rocks exposed in the Baishan area, southeastern Jilin Province, China. These new ages, together with existing age data, indicate that adakitic magmatism in southeastern Jilin Province can be subdivided into four stages: Early–Middle Triassic (251–235 Ma), Late Triassic (221–219 Ma), late Early–early Late Jurassic (176–156 Ma), and Early Cretaceous (ca. 130 Ma). Early–Middle Triassic adakitic rocks occur in a nearly E–W-trending belt within the northern margin of the northeastern North China Craton, indicating a compressional tectonic setting caused by the scissor-like closure of the Paleo-Asian Ocean from west to east. Late Triassic adakitic rocks occur in the Tonghua area and formed in an extensional setting caused by delamination after subduction and collision between the Yangtze Craton and NCC. Late Early–early Late Jurassic adakitic rocks occur in the Baishan and Kaiyuan areas and originated from partial melting of thickened lower crust in a compressional setting related to subduction of the Paleo-Pacific Plate. Early Cretaceous adakitic rocks occur in the Baishan area and were derived from partial melting of thickened lower crust above the subduction zone and delaminated lower crust, indicating that the subducting Paleo-Pacific Plate retreated to the eastern part of southern Jilin Province during the Early Cretaceous (ca. 130 Ma) and that the tectonic setting of the northeastern part of the NCC changed from compression to extension, starting in the east and progressing westward. In summary, the northeastern part of the NCC has been affected by a series of tectonic events during the Mesozoic, such as the closure of the Paleo-Asian Ocean, the collision between the NCC and YC, and the subduction of the Paleo-Pacific Plate. [ABSTRACT FROM AUTHOR]

Despite numerous years and avenues of investigation, the timing, evolution, and mechanism of lithospheric thinning of the North China Craton (NCC) are still highly debated. Late Triassic igneous rocks especially mantle derived mafic rocks could provide critical information related to the post-collisional lithospheric thinning of the Liaodong Peninsula in the eastern NCC. Using newly acquired geochronological data points, we determined that the intrusive rocks have emplacement ages of 219–209 Ma, which are typical of Late Triassic magmatism. The studied Qinghekou gabbros have low SiO2 (49.43–51.86 wt.%), Na2O+K2O (3.59–7.20 wt.%), high MgO (3.70–8.54 wt.%) and transition metal element contents, with Mg# values ranging from 49.2 to 69.3. While these samples are enriched in large ion lithophile elements such as Rb, Ba, and K and light rare earth elements, they are depleted in high field strength elements such as Nb, Ta, Ti, and P and heavy rare earth elements. We conclude that these gabbros samples were formed in a subduction-related tectonic setting, where the primary magmas were derived from partial melting of the lithospheric mantle that experienced metasomatism via slab-related fluids. Our Tongyuanpu granite samples have I-type granite affinity, as indicated by their high SiO2 (73.60–75.30 wt.%) and low MgO (0.08–0.32 wt.%) contents, as well as the A/CNK values of 0.99–1.25 and the zircon saturated temperature values of 757–832°C, the parental magmas for these granites were generated by partial melting of the lower crust. Combined with the spatio-temporal distribution and rock-assemblages of the Late Triassic intrusive rocks, we conclude that these rocks were formed in an extensional environment characterized by lithospheric thinning caused by lithospheric delamination after the collision between the NCC and the Yangtze Craton. Furthermore, we infer that the initial lithospheric thinning of the eastern NCC occurred during the Late Triassic. [ABSTRACT FROM AUTHOR]

The Central Asian Orogenic Belt (CAOB) is the largest accretionary orogenic belt in the world and its formation involved a complicated process of arc–continent collision. Large‐scale Mesozoic volcanic activity in the Great Xing'an Range (GXAR) in northeastern China, which constitutes part of the eastern CAOB, has received much recent research attention. However, the petrogenesis and formation mechanism of the late Mesozoic igneous rocks remain enigmatic. This paper investigates the geochronology, petrogenesis, and formation mechanism of late Mesozoic magmatic rocks in the Kelihe area of the GXAR based on zircon U–Pb dating, petrology, and geochemistry. Late Mesozoic magmatism in the Kelihe area occurred during the Late Jurassic (165–155 Ma) and Early Cretaceous (130–120 Ma). These igneous rocks generated by this magmatism are characterized by high SiO2 (69.97–75.49 wt%) and low MgO (0.11–0.68 wt%), Cr (10–30 ppm), Co (0.2–2.6 ppm), and Ni (0.5–1.6 ppm) contents. Trace elements show enrichment in Rb, Th, U, Zr, and K, and depletion in Ba, P, Nb, and Ti. These features indicate that the rocks were derived from partial melting of the crust. Furthermore, the rhyolites have high Na2O (5.02–5.44 wt%) and K2O (3.94–4.88 wt%) contents, similar to those of melts formed by the partial melting of basaltic crust. Combining the present results with the findings of previous studies, it is inferred that the Mesozoic igneous rocks formed in a post‐collisional extensional setting related to lithospheric thinning and asthenospheric upwelling after the closure of the Mongol–Okhotsk Ocean. [ABSTRACT FROM AUTHOR]

This paper presents geochronological, geochemical, and isotopic data relating to Devonian magmatic activity in the Jiefangyingzi area, northern margin of the North China Plate (NCP). LA‐ICP‐MS zircon U–Pb dating indicates that the Erfendi granites formed in the Middle Devonian and yield a concordant weighted mean age of 384.7 ± 2.5 Ma. The zircons have negative εHf(t) values ranging from −5.8 to −31.3 and two‐stage Hf‐model ages of TDM2 = 1,735–3,217 Ma. 206Pb/238U ages of zircon grains from a quartz–schist sample in the Shaiwusu Formation vary from 410 to 322 Ma, with a peak at 380 Ma, indicating that magmatic activity peaked during the Late Devonian. The Erfendi granites are silica‐ and alkali‐rich and calcium‐ and magnesium‐poor. The Erfendi granites belong to peraluminous rocks and have clear negative Eu anomalies (δEu = 0.49–0.84); P, Ti, and Nb depletions; Nd, Zr, and U enrichments; and high Ga/Al ratios, similar to aluminous A‐type granites. This suggests the Erfendi granites were generated by partial melting of lower crustal rocks. Geochemically, the Erfendi granites are A2‐type granites, reflecting a post‐collision tectonic setting. The southward subduction of the Palaeo‐Asian Oceanic Plate during the Early Palaeozoic formed Bainaimiao volcanic arc at the northern NCP and Deyanqimiao island arc. The collision between the Deyanqimiao island arc and the Bainaimiao volcanic arc was recorded by the Xibiehe molasse deposition and the Badangshan volcanic rocks at the northern margin of the NCP during the Late Silurian to Early Devonian. As a consequence, the Jiefangyingzi area experienced intense post‐collision extensional magmatism during the Middle Devonian, which generated massive A2‐type granites at the northern margin of the NCP. This collision was also recorded by the back‐arc deposition of the Late Carboniferous Shaiwusu Formation. [ABSTRACT FROM AUTHOR]

Many data have been reported from the Early Palaeozoic subduction complex belt and accretionary arc to the south of the Solonker‐Xar Moron‐Changchun‐Yanji Suture (SXCYS) zone. However, as the suture is covered to the east by the Mesozoic–Cenozoic Songliao Basin, there have yet been no related reports about the Early Palaeozoic igneous rocks in this area. The authors discovered an Early Palaeozoic granitoid intrusion in the Fangjiatun area, northern Liaoning, and performed petrologic, geochemical, zircon U–Pb dating and Hf isotopic analyses on it. Zircon SHRIMP U–Pb dating results show that the intrusion formed at 437–432 Ma, that is, in the late stage of the Early Silurian. Petrogeochemical analysis indicates that the intrusion records 63.14%–66.45% SiO2, with Na2O/K2O ratios of 1.01–6.12 and magnesian index (Mg#) values of 32.42–40.82. The REEs show a certain degree of LREE/HREE fractionation and slightly lower ΣREE contents. The trace elements are relatively enriched in Rb, Ba, Th, K, and Sr (large‐ion lithophile elements [LILEs]) and depleted in Nb, Ta, P, and Ti (high‐field‐strength elements [HFSEs]), displaying continental magmatic arc characteristics. The rocks have high Sr mass fractions, low Y and Yb mass fractions, and high Sr/Y ratios, which are consistent with the geochemical signatures of typical adakites. Zircon Hf isotopic analyses indicate that their εHf(t) values range from 0.29–6.56, reflecting the relatively depleted signatures of the source area. Based on its occurrence location and emplacement time, the intrusion is interpreted to have been produced by tectonic thermal events during the subduction of the Palaeo‐Asian oceanic crust beneath the northern margin of the North China Craton (NCC), thus reflecting the existence of an Early Palaeozoic continental marginal accretionary arc in the eastern segment of the NCC along the south of the SXCYS and provide new evidence for the tectonic evolution of the northern margin of the NCC in the Early Palaeozoic. [ABSTRACT FROM AUTHOR]

Northeast (NE) China is characterized by large areas of Mesozoic and Paleozoic granitoids, whereas Cenozoic granitoids are scarce. This paper reports LA-ICP-MS zircon U-Pb ages and whole-rock geochemical data for late Paleocene-early Eocene granitoids from the Jiamusi Massif, NE China, in order to determine their petrogenesis and tectonic implications. Geochronological data indicate that the granodiorite and dioritic porphyry from the Wudingshan pluton formed at 51.5 ± 0.3 Ma and 56.3 ± 0.8 Ma, respectively. The biotite-quartz diorite, biotite granodiorite, and dioritic porphyry have high SiO2 (68.38-70.06 wt.%), Al2O3 (15.34-15.79 wt.%), and Na2O (3.96-4.49 wt.%) contents, low MgO contents (1.10-1.26 wt.%), A/CNK ratios of 0.99-1.11, and are classified as medium- to high-K calc-alkaline and weakly peraluminous I-type granitoids. They are enriched in LREEs and LILEs, and depleted in HFSEs, with Nb/Ta ratios of 10.4-15.0. Moreover, they have negative Nb-Ta-Ti anomalies, indicating that they were derived from continental crust. Combining with the previously published isotopic data and regional geological results, we suggest that the late Paleocene-early Eocene granitoids (56-52 Ma) were probably derived from partial melting of juvenile lower crust, and formed in an active continental margin setting, possibly related to subduction slab rollback of the Paleo-Pacific Plate. [ABSTRACT FROM AUTHOR]

This study presents new zircon U-Pb geochronology, geochemistry, and zircon Hf isotopic data of volcanic and subvolcanic rocks that crop out in the Bayanhushuo area of the southern Great Xing’an Range (GXR) of NE China. These data provide insights into the tectonic evolution of this area during the late Mesozoic and constrain the evolution of the Mongol-Okhotsk Ocean. Combining these new ages with previously published data suggests that the late Mesozoic volcanism occurred in two distinct episodes: Early-Middle Jurassic (176-173 Ma) and Late Jurassic-Early Cretaceous (151-138 Ma). The Early-Middle Jurassic dacite porphyry belongs to high-K calc-alkaline series, showing the features of I-type igneous rock. This unit has zircon εHf(t) values from +4.06 to +11.62 that yield two-stage model ages (TDM2) from 959 to 481 Ma. The geochemistry of the dacite porphyry is indicative of formation in a volcanic arc tectonic setting, and it is derived from a primary magma generated by the partial melting of juvenile mafic crustal material. The Late Jurassic-Early Cretaceous volcanic rocks belong to high-K calc-alkaline or shoshonite series and have A2-type affinities. These volcanics have εHf(t) and TDM2 values from +5.00 to +8.93 and from 879 to 627 Ma, respectively. The geochemistry of these Late Jurassic-Early Cretaceous volcanic rocks is indicative of formation in a post-collisional extensional environment, and they formed from primary magmas generated by the partial melting of juvenile mafic lower crust. The discovery of late Mesozoic volcanic and subvolcanic rocks within the southern GXR indicates that this region was in volcanic arc and extensional tectonic settings during the Early-Middle Jurassic and the Late Jurassic-Early Cretaceous, respectively. This indicates that the Mongol-Okhotsk oceanic plate was undergoing subduction during the Early-Middle Jurassic, and this ocean adjacent to the GXR may have closed by the Late Middle Jurassic-Early Late Jurassic. [ABSTRACT FROM AUTHOR]

For the realization of morphing naturally and smoothly between two 2D shape, this paper presented a graphics morphing method based on the increment iterative transformation, and this graphics applied to the situation that the feature was not correspond between two shapes. In contrast to the existing methods, the proposed method pretreated the graphics firstly, then sampled a set of feature points from the source graphics and target graphics, and weighted and normalized the two graphics, obtained the global least squares series based on the samples and corresponding, matched them, after that generated a series of metamorphosis graphics by increment iterative transformation method. Computer simulation results show that the result gotten from the algorithm can avoid atrophy and twisted of metamorphosis graphics, and achieve the transition naturally and smoothly. [ABSTRACT FROM AUTHOR]