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The Cenozoic geological hallmark of Western Yunnan is the characteristic voluminous Late Cretaceous‐Eocene granites; however, their geological background and petrogenesis have not been well constrained and elucidated. In this study, we present new zircon U‐Pb dating, along with geochemical and Sr‐Nd‐Hf isotopic data for granites from the Tengchong–Lianghe granitoid belt (as abbreviated to Tengliang belt) and West Yingjiang batholiths from the Tengchong block. The mineralogical and geochemical features of the Tengliang granites and the West Yingjiang batholiths are ascribed to aluminous S‐type granites and weak peraluminous I‐type, respectively. Zircon U‐Pb analyses yielded consistent ages ranging from 67.5 Ma, 68.4 Ma and 66.2 Ma from the Tengliang granitoid belt and 50.4 Ma to 60.8 Ma for three samples from the west Yingjiang batholiths. The Tengliang granites were emplaced during the Late Cretaceous (68–66 Ma) and demonstrate negative εHf(t) values (–24 to –4) and initial 87Sr/86Sr ratios of 0.7101–0.7139 and significant negative εNd(t) values from –8.91 to –13.2, indicating a Proterozoic sedimentary source or enriched components. The hornblende‐bearing I‐type granites from West Yingjiang are characterized by lower initial 87Sr/86Sr ratios of 0.7076–0.7106, compared to Tengliang granite and negative whole‐rock εNd(t) values from –4.0 to –11.9. The early Eocene west Yingjiang gneissic granites show wide ranges of εHf(t) values from +7.4 to –8.5 and T2DM of 1.30–0.65 Ga, indicating partial melting of ancient crust with contributions of depleted mantle materials. In combination with the regional background and previous studies, we propose that such a spatio‐temporal distribution of the Tengchong granitoid belt might be related to the rollback or angle‐switching of the Neo‐Tethyan subducting slab. This study sheds new light on the evolutionary history of the Tengchong block. [ABSTRACT FROM AUTHOR]

It is unclear whether the South China blocks have an affinity with continental Gondwana due to a lack of direct Pan‐African magmatic and metamorphic features. In this study, we conducted U‐Pb geochronological and Lu‐Hf isotopic analyses for detrital zircons from a sandstone of the Chang'an Formation of the Nanhua Group in the Longsheng region of northern Guangxi, with the aim of constraining the timing of sedimentation and information as to its source, as well as seeking evidence for Pan‐African events in the South China blocks. The results show that the ages of detrital zircons peaked at 654.7 ± 6.2 Ma, 773.2 ± 4.1 Ma and 821.9 ± 6.5 Ma, with some at 920–870 Ma; the youngest age indicates the existence of the Pan‐African thermal event. The ∊Hf(t) and TDM2 values demonstrate that the study area has experienced three stages of crustal growth at 3.0–2.4 Ga, 2.1–1.5 Ga and 1.3–0.9 Ga. With intensively distributed Neoproterozoic mafic‐ultramafic and granitic plutons emplaced at 830–810 Ma along the southwestern section of the Jiangnan Orogenic Belt and positive ∊Hf(t) values from a large group of zircon grains, it is proposed that the sediments of the Chang'an Formation (of Nanhua Group) were largely sourced from the southeastern margin of the Yangtze block. Comparison with the zircon age spectra of the Cathaysian block shows that about 79% of the Pan‐African aged detrital zircon grains that have TDM2 = 1352–1031 Ma and ∊Hf(t) = 3.68–8.79, were sourced from the recycled Grenvillian crust of the Cathaysian block, suggesting that the Cathaysian block had a close connection with Gondwana. [ABSTRACT FROM AUTHOR]

The Jiangshan gold deposit is the largest, most recently‐discovered gold deposit in the Bengbu Uplift. The ore bodies are located in the structural fracture zone of the Zhuangzili Formation (Ar3), with major Pb‐Zn and Au reserves. In this study, LA‐ICP‐MS zircon U‐Pb analyses yielded a crystallization age of 111.5 ± 1.8 Ma for the quartz diorite porphyry in Jiangshan. The quartz diorite porphyry has high Ba and Sr content, with low Y and Yb content, which is similar to the characteristics of adakitic rocks. They are enriched in large ion lithophile elements (LILEs, e.g., Ba, U) and light rare earth elements (LREEs), while depleted in high field strength elements (HFSEs, e.g., Nb, Ti) and heavy rare earth element (HREEs). They have zircon ∊Hf(t) values of –23.52 to –21.14 (mean = –22.32). and Hf model ages of 2419.76 to 2569.39 Ma. The magma source area is the lower crust. Magma primarily came from the partial melting of the lower crust, with the addition of some mantle material. The quartz diorite porphyries are characterized by high zircon TTi‐in‐zircon values (608–757°C), Ce4+/Ce3+ ratios (71.97–1387.10) and Eu/Eu∗ ratios (0.46–1.08), indicating high temperature and magmatic oxygen fugacities. High temperatures can provide heat to fluids and highly oxidized magmas can control the behavior and speciation of sulfides, thus controlling the behavior of Au. Finally, the ore‐forming fluid is enriched and precipitated in a favorable structural space to form the Jiangshan Au deposit. [ABSTRACT FROM AUTHOR]

The eastern Hexi Corridor, northwest China, is located at the tectonic junction of the Alxa Block, the North China Craton, and the Qinling‐Qilian Orogen. The early Paleozoic Xiangshan Group record critical information regarding paleoenvironment, paleoclimate and paleotectonic setting, from which we here present a focused study on the chert beds within the Xiangshan Group. Through field mapping, microstructural observation, whole‐rock geochemistry analyses and detrital zircon dating, we suggest that the Xiangshan Group chert was deposited along a passive continental margin, formed primarily through biological activity with minor hydrothermal influence and terrestrial input. The characteristics of the chert support a low latitude sedimentary paleoenvironmental origin, and reveal the fact that the Alxa Block was separated from the North China craton, while emerged some paleogeographic affinity with the Qilian region in the Middle‐Late Cambrian. [ABSTRACT FROM AUTHOR]

The Baleigong granites, located in the western part of the southwestern Tianshan Orogen (Kokshanyan region, China), records late Paleozoic magmatism during the late stages of convergence between the Tarim Block and the Central Tianshan Arc Terrane. We performed a detailed geochronological and geochemical study of the Baleigong granites to better constrain the nature of collisional processes in the Southwest Tianshan Orogen. The LA‐ICP‐MS U‐Pb zircon isotopic analyses indicate that magmatism commenced in the early Permian (∼282 Ma). The granite samples, which are characterized by high contents of SiO2 (67.68–69.77 wt%) and Al2O3 (13.93–14.76 wt%), are alkali‐rich and Mg‐poor, corresponding to the high‐K calc‐alkaline series. The aluminum saturation index (A/CNK) ranges from 0.93 to 1.02, indicating a metaluminous to slightly peraluminous composition. Trace element geochemistry shows depletions in Nb, Ta, and Ti, a moderately negative Eu anomaly (δEu=0.40–0.56), enrichment in LREE, and depletion in HREE ((La/Yb)N=7.46–11.78). These geochemical signatures are characteristic of an I‐type granite generated from partial melting of a magmatic arc. The I‐type nature of the Baleigong granites is also supported by the main mafic minerals being Fe‐rich calcic hornblende and biotite. We suggest that the high‐K, calc‐alkaline I‐type granitic magmatism was generated by partial melting of the continental crust, possibly triggered by underplating by basaltic magma. These conditions were likely achieved in a collisional tectonic setting, thus supporting the suggestion that closure of the South Tianshan Ocean was completed prior to the Permian and was followed (in the late Paleozoic) by collision between the Tarim Block and the Central Tianshan Arc Terrane. [ABSTRACT FROM AUTHOR]

Abstract: We report here U‐Pb age and in situ Hf isotopic results for detrital and magmatic zircons from one conglomerate and four tuffite samples from the Late Triassic Nadigangri Formation across the North Qiangtang depression, Tibet. Coupled with previously published data in the region, this paper proposes new insights into the geochronological framework for the Nadigangri Formation. The deposition ages of tuffite from top to bottom in the Woruo Mountain, Quem Co and Dongqu River, are 203 Ma, 226 Ma, 221.5 Ma and 221.1 Ma, respectively. The detrital zircons yield a younger cluster of ages of 201.5–225 Ma from the conglomerate of the Quem Co Formation. The Late Triassic Nadigangri Formation defines a temporal range approximately between 201 and 225 Ma (Norian‐Rhaetian), including three predominant groups of 220–225 Ma, 210–217 Ma and 201–205 Ma, which correspond with the three main rifting episodes of initial rifting, further rifting and final rifting. Positive εHf(t) value and low model ages in younger detrital zircons suggests a juvenile character. However, the Hf isotopes of magmatic zircons display the presence of reworked ancient crust with 1.1–1.8 Ga. These results provide strong constraints not only on the temporal range of the Late Triassic Nadigangri Formation, but also on the onset of the Qiangtang Mesozoic rift basin. [ABSTRACT FROM AUTHOR]

Abstract: The Jiangla'angzong granite in the northern part of the Central Lhasa Terrane is composed of syenogranite and adamellite. LA‐ICP‐MS zircon U‐Pb analyses suggest that syenogranite has a weighted mean 206Pb/238U age of 86±1 Ma (mean square weighted deviation=0.37), which is in accordance with the muscovite Ar‐Ar age (85±1 Ma) of Cu‐Au ore‐bearing skarns and the zircon U‐Pb age (84±1 Ma) of adamellite. This suggests that the Jiangla'angzong magmatism and Cu–Au mineralization events took place during the Late Cretaceous. The granite contains hornblende, biotite, and pyroxene, and does not contain Al‐bearing minerals, such as muscovite, cordierite, and garnet. It has high contents of SiO2 (65.10–70.91wt%), K2O (3.44–5.17wt%), and total K2O+Na2O (7.13–8.15wt%), and moderate contents of A12O3 (14.14–16.45wt%) and CaO (2.33–4.11wt%), with a Reitman index (σ43) of 2.18 to 2.33, and A/CNK values of 0.88 to 1.02. The P2O5 contents show a negative correlation with SiO2, whereas Pb contents show a positive correlation with SiO2. Th and Y contents are relatively low and show a negative correlation with the Rb contents. These characteristics suggest that the Jiangla'angzong granite is a high K calc–alkaline metaluminous I–type granite. It is enriched in light rare earth elements (LREE) and large ion lithofile elements (LILE), and depleted in heavy rare earth elements (HREE) and high field strength elements (HFSE), with LREE/HREE ratios of 11.7 to 18.1. The granite has negative Eu anomalies of 0.58 to 0.94 without obvious Ce anomalies (δCe=1.00–1.04). The relatively low initial 87Sr/86Sr ratios of 0.7106 to 0.7179, positive εHf(t) values of 1.0 to 4.1, and two‐stage Hf model ages (TDM2) ranging from 889 Ma to 1082 Ma, These geochemical features indicate that the granite derived from a juvenile crust. The (143Nd/144Nd)t values from the Jiangla'angzong granite range from 0.5121 to 0.5123, its εNd(t) values range from –10.17 to –6.10, its (206Pb /204Pb)t values range from 18.683 to 18.746, its (207Pb /204Pb)t values range from 15.695 to 15.700, and its (208Pb /204Pb)t values range from 39.012 to 39.071. These data indicate that the granite was formed by melting of the upper crust with the addition of some mantle materials. We propose that the Jiangla'angzong granite was formed during the post‐collision extension of the Qiangtang and Lhasa terranes. [ABSTRACT FROM AUTHOR]

The article focuses on a study related to tectonic response of Guanzhong Basin of Qinling orogenic belt in China. It includes information on the geological concerns of the presence of detrital sedimentary rocks in Guanzhong Basin. It also includes information on the analysis of zircon samples from Guanzhong Basin and Cretaceous teritary sandstones.

The article discusses about Zircon U‐Pb Age of the Granodiorite in the Chifeng at Northern Margin of the North China Craton and the Constraints on the Plate Tectonic Evolution. It is concluded that suite of granodiorite was identified in Zhuanshanzi and Yuanbaoshan area in eastern Chifeng atnorthern margin of NCC.

Abstract: The Mianning–Dechang (MD) rare earth element (REE) belt, located in the northern Kangdian axis (KDA) in the western margin of the Yangtze platform, is one of the most economically significant REE mineral belts in China. REE mineralization is associated with Himalayan carbonatite–alkaline complexes. The Lizhuang nordmarkite occurred in the northern part of the MD REE belt. The majority of zircons from the Lizhuang nordmarkite are characterized by pronounced positive Ce yet slightly negative Eu anomalies and high U/Yb. Moreover, all zircons have stable Hf isotopic compositions with initial 176Hf/177Hf ratios ranging from 0.282739 to 0.282808 and an average value of 0.282773. The negative Lu/Hf and positive εHf(t) range from −0.98 to −0.94 (average value of −0.96) and from −0.56 to 1.89 (the majority is positive, with an average of 0.66), respectively. These characteristics indicate that the rock is derived from an enriched mantle and subducted material. LA‐ICP‐MS analysis of the zircons from the intrusion yields a weighted mean 206Pb/238U age of 28.57±0.61Ma. During this period, the tectonic activity in the KDA is not plate subduction but an intraplate tectonic exhibiting fold–thrust and strike–slip behaviors in the western marginal zone of the Yangtze platform (WMYB). We suggest the possibility of an existing eastward old slab subduction under WMYB combined with a regional tectonic evolution. The Lizhuang nordmarkite may be derived from an enriched mantle beneath the western part of the Yangtze craton, which originated from the remelting of the Tethys subducting slab, because of the Himalayan strike–slip that formed a special type of REE deposit called strike–slip‐type REE deposits. [ABSTRACT FROM AUTHOR]

The Berezitovoe deposit is a large-sized Au-Ag-Zn-Pb deposit in the east of the Selenga-Stanovoi superterrane, Russia. Au-Ag orebodies are hosted by tourmaline-garnet-quartz-muscovite metasomatic rocks; Zn-Pb orebodies are hosted by granodiorites, porphyritic granites and tourmaline-garnet-quartz-muscovite metasomatic rocks. These orebodies are surrounded by wall rocks dominated by the Tukuringra Complex granodiorites, porphyritic granites, and gneissic granodiorites. The alteration includes silicification and garnet, sericitization chloritization, carbonatization and kaollinization. LA-ICP-MS U-Pb zircon dating indicates that the gold mineralization can be divided into two stages in the Berezitovoe polymetallic gold deposit (at 363.5 ± 1.5 Ma, and 133.4 ± 0.5). Hornblende-plagioclase gneisses of the Mogocha Group in the study area underwent Paleoproterozoic metamorphism (at 1870 ± 7.8 and 2400 ± 13 Ma), gneissic granodiorite of the Tukuringra Complex yields a late Paleozoic magmatic age (at 379.2 ± 1.1 Ma), and subalkaline porphyritic granitoid of the Amudzhikan Complex yield late Mesozoic magmatic ages (133-139 and 150-163 Ma). Granodiorites of the Tukuringra Complex in the study area have high concentrations of SiO2 (average of 60.9 wt%), are aluminum-oversaturated (average A/CNK of 1.49), are enriched in the large ion lithophile elements (e.g., K, Rb, and Ba), U, Th, and Pb, are depleted in high field strength elements (e.g., Ta, Nb, and Ti), and have slightly negative Eu and no Ce anomalies in chondrite-normalized rare earth element diagrams. Fluid inclusions from quartz veins include three types: aqueous two-phase, CO2-bearing three-phase, and pure CO2. Aqueous two-phase inclusions homogenize at 167°C-249°C and have salinities of 4.32%-9.47% NaCl equivalent, densities of 0.86-0.95 g/cm3, and formed at depths of 0.52-0.94 km. In comparison, the CO2-bearing three-phase inclusions have homogenization temperatures of 265°C-346°C, salinities of 7.14%-11.57% NaCl equivalent, and total densities of 0.62-0.67 g/cm3. The geochemical and zircon U-Pb data and the regional tectonic evolution of the study area, show that the Berezitovoe polymetallic gold deposit formed in an island arc or active continental margin setting, most probably related to late Paleozoic subduction of Okhotsk Ocean crust beneath the Siberian Plate. [ABSTRACT FROM AUTHOR]

The article reports that a Mesoarchean tonalitic gneiss was found in Northern Liaoning Province, China. According to the author, the tonalitic gneiss is considered to be an ancient lithotectonic element on the bases of zircons isotopic dating. The author suggests that other ancient rocks can be discovered with the outcrops and drill holes in the North China Craton.

The Tongshankou Cu-Mo deposit, located in southeast Hubei province, is a typical skarn-porphyry type ore deposit closely related to the Tongshankou granodiorite porphyry, characterized by a high Sr/Y ratio. Detailed in situ analyses of the trace elements and U-Pb and Lu-Hf isotopes in zircons from the Tongshankou granodiorite porphyry were performed. Scarcely any inherited zircons were observed, and the analyzed zircons yielded highly concordant results with a weighted mean 206Pb/238U age of 143.5 ± 0.45 Ma ( n=20, mean square weighted deviation was 0.75), which was interpreted to represent the crystallization age of the Tongshankou granodiorite porphyry. The chondrite-normalized rare-earth element pattern was characterized by a slope that steeply rises from the light-group rare-earth elements (LREE) to the heavy-group rare-earth elements (HREE) with a positive Ce-anomaly and inconspicuous Eu-anomaly, which was coincident with the pattern of the zircons from the Chuquicamata West porphyry, Chile. The analyzed zircons also had relatively low 176Hf/177Hf ratios of 0.282526-0.282604. Assuming t=143 Ma, the corresponding calculated initial Hf isotope compositions ( εHf( t)) ranged from −5.6 to −2.9. The results of the in situ analysis of trace elements and U-Pb and Lu-Hf isotopes in zircons from the Tongshankou granodiorite porphyry suggest that a deep-seated process involving a thickened-crust/enriched-mantle interaction may play an important role in the generation of high Sr/Y-ratio magma and potentially in the generation of porphyry Cu-Mo systems. [ABSTRACT FROM AUTHOR]

The morphology, REE geochemistry and U-Pb geochronology of zircons from quartz monzodiorite in the Sunzhuang area, Fanshi County, Shanxi Province are presented in this study. The zircon crystals can be classified into four main types as: AB, L, S and P, and 24 subtypes such as AB4, AB5, L5, and S3. The maximum crystallization temperature of zircon was estimated as 850°C, with the minimum of 550°C. The peak temperatures of the zircon crystallization range from 650°C to 700°C. The abundances of Th and U in the zircon grains show large variation with the Th/U values > 0.4. The Th and U values also show a positive correlation in most zircons. The REE abundance of zircon in the quartz monzodiorite ranges from 280.4 ppm to 2143 ppm with an average of 856.4 ppm. The chondrite normalized zircon REE patterns show two types, one is characterized by HREE enrichment and LREE depletion with positive Ce-anomaly and negative Eu-anomaly whereas the other is HREE enriched and LREE depleted with negative Eu-anomaly but without positive Ce-anomaly, and relatively flat patterns. The LA-ICP-MS U-Pb geochronology on the zircons yields a mean age of 133±0.87 Ma. Our data on zircon morphology, composition and U-Pb geochronology reveal that the parent magma of the quartz monzodiorite which was emplaced during late Yanshanian had a mixed crust-mantle source, with crustal components dominating. The magma is inferred to have been water rich and alkaline with initial high oxygen fugacity. Post-magmatic hydrothermal activity occurred under relatively reducing conditions which was conductive for gold precipitation in the Yixingzhai gold deposit. [ABSTRACT FROM AUTHOR]

Investigation of the petrogenesis and the origin of zircons from the volcanic rocks of the Liujiaping Group of the back-Longmenshan tectonic belt in the northwest margin of the Yangtze Block is conducted by analysis of U-Pb geochronology and geochemistry. Results show that selected zircons are characterized by internal oscillatory zonings and high Th/U ratios (0.43-1.18), indicating an igneous origin. Geochronological results of LA-ICP-MS U-Pb dating of the Liujiaping Group zircons yield an age of 809 ± 11 Ma (MSWD = 2.2), implying that the volcanic rocks were formed in the Late Neoproterozoic. Geochemical analysis shows that the rocks are calc-alkaline, supersaturated in Al, and metaluminous to weakly peraluminous. Rare-earth elements are present at high concentrations (96.04-265.48 ppm) and show a rightward incline and a moderately negative Eu anomaly, similar to that of continental rift rhyolite. Trace element geochemistry is characterized by evident negative anomalies of Nb, Ta, P, Th, Ti, inter alia, and strong negative anomalies of K, Rb, Sr, et al. We conclude that the Liujiaping Group volcanic rocks resulted from typical continental crust source petrogenesis and were formed in a continental margin setting, which had no relation to subduction, and thus, were the products of partial melting of the lower crust due to crustal thickening caused by active continental margin subduction and arc-continent collision orogeny in the northwestern Yangtze Block and were triggered by the breakup of the Rodinia supercontinent during the Neoproterozoic. [ABSTRACT FROM AUTHOR]

The Banshanping granitoid rocks distribute in the east of the North Qinling orogenic belt. It is a diorite-quartz diorite-granodiorite-granite series, spreading in a NW-SE direction, and intrudes into the Erlangping Group. The SiO2 content ranges from 57.04% to 76.56%, Na2O from 2.05% to 4.65%, K2O from 0.84% to 3.40%. Major element characteristics indicate that Banshanping granitoid rocks have properties of I type granotoids. SREE ranges from 36.51 ppm to 473.25 ppm, and LREE/HREE ratios lie between 3.95 and 22.18. Negative Eu anomalies are not obvious in most samples, though there are obvious Nb, P and Ti positive anomalies. The zircon LA-ICP-MS ages of Banshangping granitoid rocks are 496.0±8.1 Ma-486.9±9.3 Ma. Hf isotope shows that 176Hf/177Hf ratios range from 0.282721 to 0.282876, εHf( t) values from 8.5 to 14, all positive, and corresponding modal ages (TDM2) range from 559 Ma to 908 Ma. Based on Hf isotope characteristics and existing Sm-Nd and Rb-Sr isotope data, we consider that the Banshanping granitoid rocks originate from mantle-derived material, i.e. the igneous rocks that formed in Neoproterozoic, and there may be a certain amount of crust-derived material during the formation of Banshanping granitoid rocks. [ABSTRACT FROM AUTHOR]

This study focuses on the zircon U-Pb geochronology and geochemistry of the Bairiqiete granodiorite intrusion (rock mass) from the Buqingshan tectonic mélange belt in the southern margin of East Kunlun. The results show that the zircons are characterized by internal oscillatory zoning and high Th/U (0.14-0.80), indicative of an igneous origin. LA-ICP-MS U-Pb dating of zircons from the Bairiqiete granodiorite yielded an age of 439.0 ± 1.9 Ma (MSWD = 0.34), implying that the Bairiqiete granodiorite formed in the early Silurian. Geochemical analyses show that the rocks are medium-K calc-alkaline, relatively high in Al2O3 (14.57-18.34 wt%) and metaluminous to weakly peraluminous. Rare-earth elements have low concentrations (45.49-168.31 ppm) and incline rightward with weak negative to weak positive Eu anomalies (δ5Eu = 0.64-1.34). Trace-element geochemistry is characterized by negative anomalies of Nb, Ta, Zr, Hf and Ti and positive anomalies of Rb, Th and Ba. Moreover, the rocks have similar geochemical features with adakites. The Bairiqiete granodiorite appears to have a continental crust source and formed in a subduction-related island-arc setting. The Bairiqiete granodiorite was formed due to partial melting of the lower crust and suggests subduction in the Buqingshan area of the Proto-Tethys Ocean. [ABSTRACT FROM AUTHOR]

In this paper we present new zircon U-Pb ages, whole-rock major and trace element analyses, and zircon Hf isotopic data for magmatic rocks in the Tuotuohe region of the western segment of the Jinshajiang suture. Our aim is to constrain the Early Permian-Late Triassic tectonic evolution of the region. Zircons from the magmatic rocks of the Tuotuohe region are euhedral-subhedral in shape and display fine-scale oscillatory zoning as well as high Th/U ratios (0.4-4.6), indicating a magmatic origin. The zircon U-Pb ages obtained using LA-ICP-MS are 281 ± 1 Ma, 258 ± 1 Ma, 244 ± 1 Ma, and 216 ± 1 Ma, which indicate magmatism in the Early Permian-Late Triassic. A diorite from Bashihubei (BSHN) has SiO2= 57.18-59.97 wt%, A12O3= 15.70-16.53 wt%, and total alkalis (Na2O + K2O) = 4.46-6.34 wt%, typical of calc-alkaline and metaluminous series. A gabbro from Bashibadaoban (BSBDB) belongs to the alkaline series, and is poor in SiO2 (45.46-54.03 wt%) but rich in A12O3 (16.19-17.39 wt%) and total alkalis (Na2O + K2O = 5.48-6.26 wt%). The BSHN diorite and the BSBDB gabbro both display an enrichment of LREEs and LILEs and depletion of HFSEs, and they have no obvious Eu anomaly; they have relatively low MgO contents (2.54-4.93 wt%), Mgs# values of 43 to 52, and low Cr and Ni contents (8.07-33.6 ppm and 4.41-14.2 ppm, respectively), indicating they differentiated from primitive mantle magmas. They have low Nb/U, Ta/U, and Ce/Pb ratios (1.3-9.6, 0.2-0.8, and 0.1-18.1, respectively), and their initial Hf isotopic ratios range from +9.6 to +16.9 (BSHN diorite) and +6.5 to +12.6 (BSBDB gabbro), suggesting their primary magmas were derived mainly from the partial melting of a mantle wedge that had been metasomatized by subduction fluids. Taking all the new data together, we conclude that the western and eastern segment of the Jinshajiang suture regions underwent identical processes of evolution in the Early Permian-Late Triassic: oceanic crust subduction before the Early Permian, continental collision during the Early-Middle Triassic, and post-collisional extension from the Late Triassic. [ABSTRACT FROM AUTHOR]

Albitite often accompanies with various metal and gem mineral deposits and a large number of occurrences have been reported globally, including the South Qinling orogen, China. The Xiaozhen copper deposit is a typical deposit in the North Daba Mountain area of the South Qinling orogen whose distribution is controlled by albitite veins and fractures. As there are few studies on the petrogenesis of albitite in Xiaozhen copper deposit, this paper focuses on the petrogenesis of albitite and its mineralization age. Detailed fieldwork and mineral microscopic observations initially suggest that albitite from the Xiaozhen copper deposit is igneous in origin. Further zircon trace element geochemistry studies indicate that these zircons have high Th/U ratios (>0.5), low La content, high (Sm/La)N and Ce/Ce* values, and a strong negative Eu anomaly, which are commonly seen in magmatic zircons. The chondrite-normalized rare earth element (REE) patterns are consistent with magmatic zircons from throughout the world, and they fall within or near the field of magmatic zircons on discriminant diagrams. The calculated average apparent Ti-in-zircon temperature for young zircons is 780°C, consistent with magmatic zircon crystallization temperatures. Therefore, zircon geochemistry indicates that the albitite origin is magmatic. SIMS U-Pb dating on nine magmatic zircons yielded a concordia age of 154.8±2.2 Ma, which represents the formation of albitite and the metallogenic age. More importantly, it is consistent with the ages of Yanshanian magmatism and metallogenesis in the South Qinling orogen, so formation of the Xiaozhen copper deposit may be a closely related geological event. [ABSTRACT FROM AUTHOR]

U-Pb zircon age, geochemical, and Sr-Nd-Pb isotopic data of mafic dykes from eastern Shandong Province, eastern China is reported herein. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon analyses of two samples from the investigated mafic dykes yield consistent ages ranging from 121.9 Ma ± 0.47 Ma to 122.9 Ma ± 0.61 Ma. The mafic dykes are characterized by high (87Sr/86Sr)i ranging from 0.7087 to 0.7089, low εNd( t) values ranging from −16.9 to −17.8, 206Pb/204Pb = 17.15 to 17.17, 207Pb/204Pb = 15.45 to 15.47, and 208Pb/204Pb = 37.59 to 37.68. Results from the current study suggest that the mafic dykes are derived from partial melting of ancient lithospheric mantle that was variably hybridized by melts derived from foundered lower crustal eclogite. The mafic dykes may have been generated through subsequent insignificant crystal fractionation and very minor crustal contamination during magma ascent. Combined with previous studies, the current findings provide new evidence that the intense lithospheric thinning beneath the eastern Shandong Province of eastern China occurred at ∼120 Ma, and that this condition was caused by the removal of the lower lithosphere (mantle and lower crust). [ABSTRACT FROM AUTHOR]

The article presents abstracts on geological topics which include the origin and structure of zircon in metamorphic rocks, the role of fluids during processes involving the continental crust, and geochemical characteristics of granites found in the Dabie Mountains, China.

Late Hercynian-early Indosinian (Triassic) granite is widely distributed around the Taer region of the northern margin of West Kunlun. The rock mass is mainly composed of calcalkaline porphyroid biotite adamellite and characterized by SiO2-rich, high-Ca, moderate-alkaline, and strongly peraluminous attributes, and relatively low ΣREE with LREE enrichment and a moderate Eu anomaly. As shown in the trace element spider web diagram, distinct peaks appear for Th, La, Nd, and Zr and clearly low values appear for Ba, Nb, Sr, P, and Ti. Further, compared with the primitive mantle, Rb/Sr and Rb/Ba are considerably higher and Nd/Th and Nb/Ta are relative low, all falling into the scope of the crust-origin rocks, indicating the characteristics of the crust-origin S-type granite. The rock mass's zircon U-Pb isotopic age is determined to be 235.7 ± 3.9 Ma. On the basis of the age data, spatio-temporal location, lithology, and geochemistry of the rock mass, we conclude that the formation of the rock mass is closely related to the strong compressional orogenic movement (240 Ma) of the Tianshuihai terrane and the South Kunlun terrane. The rock mass is the product of the collision orogenic movement. However, distinct differences are observed between the studied rock mass and the synorogenic Bulunkou rock mass, which may be caused by the different collision strength and different positions with respect to the collision zone. [ABSTRACT FROM AUTHOR]

The article describes research report on Detrital Zircon U-Pb Geochronology of the Triassic Sandstones from the Yanyuan Basin of Southwestern Sichuan, China. Topics discusses include Triassic sandstones in the Yanyuan Basin record different detrital zircon geochronology signals; and supported by the Sichuan Science and technology program the open fund of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology.

The article reports on the discovery of Tonalitic Gneiss in Southern Jilin Province, China. Topics include the rock samples which were collected from Baishan City, China from which zircons were separated and analyzed, the composition of the tonalitic gneiss which included plagioclase, quartz and biotite, and the plasma derived from basaltic materials.

The article reports on the discovery of 341 Ma gabbro, that is located inXiongcun copper-gold district at southern margin of Lhasa terrane, Tibet. The methods employed and photographs of Xiongcun gabbro, marble and migmatization gneissare are presented. Zircon U-Pb ages of the gabbro in west of Xiongcun district are 341.55±0.89 Ma

The article reports on the research study on the first Discovery and Zircon U‐Pb Dating of the Early Ordovician Granitoids in the area of Lincang Batholith, Western Yunnan. Implications of Proto‐Tethyan Orogeny in Sanjiang Region, South West China are mentioned. From Petrological and geochronological data it could be concluded that Ordovician magmatism had occured in Lincang batholith.

The article provides information on the study conducted in the Bohai Bay Basin (BBB) to determine the geology of the basement rocks including the separation and imaging of zircon crystals using cathodoluminescence (CL). Particular focus is given to the results of the study including the presence of tonalite, oscillatory zoning, and magmatic zircons of the same age. Also discussed is the magmatism in North China Craton (NCC).

The article reports that a new discovery of a 1.8 Ga Erlongshan monzonitic granite has been done on the Western Margin of the Songnen Masiff, China. It mention about the samples of zircon dating geochemical testing have been collected. It states about the characteristics of the zircon crystals related to their color and texture.

The article presents a study which discusses petrogenesis and significance the Jebel Dumbier Alkaline-carbonatite complex from North Margin of Nuba Mountains, Sudan. the genetic relationships of the fluorite, carbonatite and distinct syenitic rocks, appearance of ditroite, and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) zircon dating results.

The article presents a study which analyses the new Zircon SHRIMP U-Pb ages of the Langjiu formation volcanic rocks in the Shiquanhe Area in Western Lhasa Terrane. Topics include distribution of potassic and ultrapotassic rocks, geochronological study on the Langjiu Formation volcanic rocks, and magmatic activity of the Linzizong group volcanic rocks.

The article focuses on a research paper discussing the petrogenesis and geology of the Gangdese porphyry copper deposits in the Tibetan-Himalayan orogen. It analyzes the hafnium-oxygen (Hf-O) isotopes in zircon of the deposit to determine the generation of copper deposits. It also suggest that the mantle component plays an important role in forming giant ore deposits.

The article focuses on a research paper discussing the geological significance of the Zhuoma copper polymetallic deposit in Geza Arc metallogenic belt in Yunnan Province, China. It discusses the laser ablation?inductively coupled plasma?mass spectrometry (LA-ICP-MS) uranium?lead (U?Pb) dating to determine U-Pb ages of zircon. It also suggest that the band structure development shows the characteristics of magma genesis of zircon.

The article focuses on a study that investigates geochronology and characteristics of fluid inclusion in the Jinchang deposit in Hainan province, China and their geological significances. The study reveals that ore-forming fluid of the gold deposit were derived from magmatic water mixed with meteoric water during the ore-process. Also discussed is the result of Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) analysis zircons from the wall rocks of ore in the deposits.

The article discusses the research study to examine the evolution of granitic magmas and implications for Molybdenum (Mo) deposit formation within the Luanchuan Metallogenic Belt, Eastern Qinling Orogen, Central China. Topics discussed include Zircon Uranium (U)? lead (Pb) dating of lithologically distinct plutons, Pb isotope compositions of pyrites that were coprecipitated with molybdenite, and multiple stages of magmatic evolution.

The article presents a study which focuses on time limit for formation of Permian bauxite deposits located in Southeast Yunnan Province, China. Topics discussed include sharp contact between the bauxite horizon and the Middle Permian or Upper Carbonic carbonate bedrock; conduction of U-Pb analysis of zircons to conduct the study and erosion of the detrital zircons revealing nearness of the parent rocks to the bauxite deposits.

The article presents a study on uranium?lead (U-Pb) dating and laser ablation?inductively coupled plasma?mass spectrometry (LA-ICP-MS) of Middle Permian granite of Langshan Mountain, China and its indicating significance. Topics discussed include characteristics of granite such as finegrained texture and massive structure; chemical composition of granite and selection of zircon to carry on LA-ICP-MS U-Pb dating.

The article discusses the evolution process and Zircon ages of the granites in the early Palaeozic period found in the Northern Tian Shan Orogenic Belt in Kyrgyzstan. Topics mentioned include the accretionary processes which attracted concern from geologists, the analysis on zircons from granite and granodiorite samples using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), and the result that granite plutons intrude during the occurence of the Terskey Ocean subduction.

The article presents a study on the progress on zircon uranium-lead (U-Pb) isotopic geological dating technique. Topics discussed include benefits of zircon U-Pb dating in comparison to other isotope dating techniques; the ongoing development of zircon U-Pb isotope dating technique in the high time resolution (high-precision) and high spatial resolution; and the use of isotope dilution-thermal ionization mass spectrometry (ID-TIMS) by the high time resolution.