Geochemical characterization of Granitoids in Katchuan Irruan area: further evidence for peraluminous and shoshonitic compositions and post-collisional setting of granitic rocks in the Precambrian Basement Complex of Nigeria

Petrographic studies on Granitoids from Katchuan Irruan and adjoining areas,southeastern Nigeria,has shown that they are garnetiferous biotite granite,aplitic granite,porphyritic hornblende biotite granite,porphyritic muscovite biotite granite,weakly foliated leucogranodiorite and simple pegmatite.They are closely associated with the Precambrian Basement Complex rocks which they intruded.Modal analysis shows that the rocks consist of quartz(10%-25%),oligoclase(10%-30%),K-feldspar(15%-35%),biotite(3%-25%),with occasional garnet,hornblende,muscovite,and accessory chlorite,haematite and magnetite.Geochemical data indicates that the rocks are generally shoshonitic,alkali-calcic to calcic,ferroan and peraluminous.They are enriched in large ion lithophile elements as well as high field strength elements(Hf,Ta,Yb,Sm,Zr and Y).Their trace elements and REE patterns are similar,indicating that they are co-genetic.They are characterized by high fractionation factor(La/Yb)N(3.04-228.44)and pronounced negative Eu anomalies(Eu/Eu*)(0.23-0.71).Their overall geochemical features indicate that they were most likely derived from partial melting of crustal materials in an orogenic(post-collisional)tectonic setting.They are therefore related to the Pan-African granites,otherwise known as the Older Granites which were emplaced during the Pan African orogenic event.

Federated Learning Model for Auto Insurance Rate Setting Based on Tweedie Distribution

In the assessment of car insurance claims,the claim rate for car insurance presents a highly skewed probability distribution,which is typically modeled using Tweedie distribution.The traditional approach to obtaining the Tweedie regression model involves training on a centralized dataset,when the data is provided by multiple parties,training a privacy-preserving Tweedie regression model without exchanging raw data becomes a challenge.To address this issue,this study introduces a novel vertical federated learning-based Tweedie regression algorithm for multi-party auto insurance rate setting in data silos.The algorithm can keep sensitive data locally and uses privacy-preserving techniques to achieve intersection operations between the two parties holding the data.After determining which entities are shared,the participants train the model locally using the shared entity data to obtain the local generalized linear model intermediate parameters.The homomorphic encryption algorithms are introduced to interact with and update the model intermediate parameters to collaboratively complete the joint training of the car insurance rate-setting model.Performance tests on two publicly available datasets show that the proposed federated Tweedie regression algorithm can effectively generate Tweedie regression models that leverage the value of data fromboth partieswithout exchanging data.The assessment results of the scheme approach those of the Tweedie regressionmodel learned fromcentralized data,and outperformthe Tweedie regressionmodel learned independently by a single party.

Early Devonian Post-collisional Granitic Magmatism in the North Qilian Orogenic Belt,Western China:Insights into Lithospheric Delamination and Orogenic Collapse

Post-collisional magmatism contains important clues for understanding the reworking and growth of continental crust,as well as lithospheric delamination and orogenic collapse.Early Devonian magmatism has been identified in the North Qilian Orogenic Belt(NQOB).This paper reports an integrated study of petrology,whole-rock geochemistry,Sm-Nd isotope and zircon U-Pb dating,as well as Lu-Hf isotopic data,for two Early Devonian intrusive plutons.The Yongchang and Chijin granites yield zircon U-Pb ages of 394-407 Ma and 414 Ma,respectively.Both of them are characterized by weakly peraluminous to metaluminous without typical aluminium-rich minerals,LREE-enriched patterns with negative Eu anomalies and a negative correlation between P_(2)O_(5) and SiO_(2) contents,consistent with geochemical features of I-type granitoids.Zircons from the studied granites display negative to weak positive ε_(Hf)(t)values(−5.7 to 2.1),which agree well with those of negative ε_(Nd)(t)values(−6.4 to−2.9)for the whole-rock samples,indicating that they were derived from the partial melting of Mesoproterozoic crust.Furthermore,low Sr/Y ratios(1.13-21.28)and high zircon saturation temperatures(745℃ to 839℃,with the majority being>800℃)demonstrated a relatively shallow depth level below the garnet stability field and an additional heat source.Taken together,the Early Devonian granitic magmatism could have been produced by the partial melting of ancient crustal materials heated by mantle-derived magmas at high-temperature and low-pressure conditions during postcollisional extensional collapse.The data obtained in this study,when viewed in conjunction with previous studies,provides more information about the tectonic processes that followed the closure of the North Qilian Ocean.The tectonic transition from continental collision to post-collisional delamination could be constrained to~430 Ma,which is provided by the sudden decrease of Sr/Y and La/Yb ratios and an increase in zircon ε_(Hf)(t)values for granitoids.A two-stage tectonic evolution model from continental collision to post-collisional extensional collapse for the NQOB includes(a)continental collision and crustal thickening during ca.455-430 Ma,characterized by granulite-facies metamorphism and widespread low-Mg adakitic magmatism;(b)post-collisional delamination of thickened continental crust and extensional collapse of orogen during ca.430-390 Ma,provided by coeval high-Mg adakitic magmatism,A-type granites and I-type granitoids with low Sr-Y ratios.

Arterial Hypertension-Related Factors within Custodial Settings of Southern Benin in 2023

Introduction: Hypertension, a non-communicable disease, is a major public health threat worldwide, accounting for a high level of morbidity and mortality. Although it has been extensively published among the general population, further research is needed to understand the reality of hypertension within the custodial setting. This study aimed to investigate the factors associated with arterial hypertension in custodial settings in southern Benin in 2023. Methods: This was a cross-sectional, descriptive, analytical study held in prisons in southern Benin from March to April 2023, involving inmates selected by two-stage random sampling. In the first stage, four prisons out of the six in the southern region of Benin were selected by simple random sampling. In the second stage, the prisoners were selected by systematic random sampling, with the sampling frame being the numbered list of eligible prisoners in each prison selected. Data collected by observation and questionnaire survey were analyzed using Stata 11 software. Hypertension was defined as systolic blood pressure ≥ 140 mmHg and diastolic blood pressure ≥ 90 mmHg. Overweight was defined by a body mass index (weight/height2 (kg/m2) ≥ 25. Factors associated with hypertension were identified by multiple logistic regression, at a 5% threshold of significance. Results: Altogether 336 inmates aged 37.55 ± 1.72 years were surveyed. The prevalence of hypertension in custodial settings in southern Benin in 2023 was 31.32% (95% CI [17.06;52.57]). Associated factors were inmate age (ORa = 3.36 95% CI: [1.94;5.85]) and abnormal waist circumference (ORa = 2.61 95% CI [1.27;5.40]). Conclusion: The prevalence of arterial hypertension in prisons of southern Benin (31.32%) is high when compared with the national average (25.9% (22.5-29.3)). The ministries of the Interior and Health need to collaborate to involve inmates in preventive strategies for non-communicable diseases, including hypertension.

Development of a High Early Strength Non-fuorine and Non-alkaline Flash Setting Admixture and Flash Mechanism

To solve the problems of high rebound rate and strength reversion of shotcrete,a non-fluorine and non-alkaline liquid flash setting admixture(FSN)with low rebound and high early strength was synthesized under 60-65℃water bath environment through orthogonal test design and taking setting time and compressive strength as indicators.The experimental results show that the optimum mass ratio of FSN is aluminum sulfate:diethanolamine:triethanolamine:pseudo-boehmite:lithium carbonate:water=57%:8%:0.05%:2%:2%:31%.When FSN is added with 7%of the mass of portland cement,the cement paste can be initially set in 3 min and finally set in 5 min.The compressive strength of mortar is 1.2 MPa at 6 h,18.0 MPa at 1 d,and more than 100%at 28 days;The microscopic analysis shows that the rapid release of Li^(+),NH^(4+),and CO_(3)^(2-)ions by FSN in the paste solution effectively shortens the induction period of high C_(3)S content in Portland cement,directly forms early coagulation AFt crystals in FSN and CH dominated by Al_(2)(SO_(4))_(3),and forms a large number of C-S-H gels in the later stage,so that the cement can quickly coagulate and harden,and the strength in the later stage is not retracted.

Prospective randomized study to evaluate and compare the post-procedural sexual function in patients undergoing semi-rigid ureterorenoscopy for distal ureteric stones in three different operating room settings

Objective:To evaluate and compare the effect of semi-rigid ureterorenoscopy on post-procedural sexual function with three different operating room settings.Methods:In this prospective randomized study,consecutive sexually active patients with normal pre-operative sexual function undergoing uncomplicated semi-rigid ureterorenoscopy for distal ureteric stones were randomized into three groups,with three different operating room settings.Procedure-related anxiety and sexual function were assessed pre-operatively using Amsterdam Preoperative Anxiety and Information Scale and Brief Sexual Function Inventory(in males)and Female Sexual Function Index-6(in females),respectively.All the participants were stented following the procedure,and the stent was removed after 3 weeks.Post-procedural sexual function and general discomfort were assessed and compared between three groups at 1 week,3 weeks,and 12 weeks.The effect of surgery-related anxiety,preoperative sexual function,age,and general discomfort(including stent-related discomfort)on post-procedural sexual function were analyzed using multiple regression analysis.A p-value of less than 0.05 was considered statistically significant.Results:Totally,327 eligible patients were randomized into three groups.The group of patients who underwent the procedural with a screen separating the operating area from the patient vision,while the patient could watch the endoscopy through a separate monitor,had better post-procedural sexual function compared to those who had total vision of the operating area as well as to those whose eyes were blocked.This difference was statistically significant.This post-procedural reduction in sexual function could not be attributed to in situ stent alone.Conclusions:Our study showed that semi-rigid ureterorenoscopy can have significant negative effect on sexual function,which can be reduced with proper preoperative counseling and an ideal operating room settings.

Watson-Jones Anatomical Approach for Open Reduction and Internal Fixation of Proximal Femoral Fractures without Image Intensifier in a Low-Resource Setting

Introduction: Standard procedures for surgical fixation of proximal femoral fractures (PFF) require an image intensifier which in developing countries remains a luxury. We hypothesized that, with a well-codified technique, the Watson Jones approach (WJA) without image intensifier nor traction table, can allow open reduction and internal fixation (ORIF) of PFF using Dynamic hip screw (DHS), with satisfactory outcome. Patients and methods: Forty one consecutive patients (mean age 59.5 ± 21.6 years, 61% males) who were followed in a Teaching Hospital for PFF treated by ORIF using the WJA and DHS from January 2016 to December 2020 were reassessed. The outcome measures were the quality of the reduction, the positioning of the implants, the tip-apex distance (TAD), the rate and delay of consolidation, the functional results using Postel Merle d’Aubigné (PMA) score, the rate of surgical site infection (SSI) and the overall mortality. Logistic regression was used to determine factors associated with mechanical failure. Results: The mean follow-up period was 33.8 ± 15.0 months. Fracture reduction was good in 31 (75.6%) cases and acceptable in 8(19.5%) cases. Implant position was fair to good in 37 (90.2%) patients. The mean TAD was 26.1 ± 3.9 mm. Three patients developed SSI. Consolidation was achieved in 38 (92.6%) patients. The functional results were good to excellent in 80.5% of patients. The overall mortality rate was 7.3%. There were an association between mechanical failure and osteoporosis (p = 0.04), fracture reduction (p = 0.003), and TAD (p = 0.025). In multivariate logistic regression, no independent factors were predictive of mechanical failure. Conclusion: This study shows that ORIF using DHS for PFF via the Watson-Jones approach without an image intensifier can give satisfactory anatomical and functional outcomes in low-resource settings. It provides and validates a reliable and reproducible technique that deserves to be diffused to surgeons in austere areas over the world.

Age and geochemical evolution of granite magmatism in Olkhon region from Caledonian syncollisional ore-free granite to the rare metal granite and pegmatite of Middle Paleozoic intraplate setting

The detailed description of two granite complexes in the Olkhon subterrane is given.The Early Paleozoic Sharanur complex was formed by granitization of gneisses of the Olkhon series.It includes migmatites,granite-gneisses,granites and pegmatites of normal alkalinity;they belong to the type of syncollisional granites.The Middle Paleozoic Aya granite complex includes mother Aya massif of amazonite-bearing granites and several types of rare-metal pegmatites.They have elevated alkalinity,low of Ba,Sr,and high LILE and HFSE elements contents.The Aya pegmatites lie in northwest cracks of stretching and associated with the rise of the territory under the influence of the North Asian plume.These cracks and pegmatites mark the beginning of a new intraplate geodynamic setting.Two geochemical types are distinguished among the pegmatites of this complex.These are amazonite pegmatites of Li-F type with Ta mineralization and complex type pegmatite with Be-Rb-Nb-Ta and Li-F mineralization(the Ilixin vein).The Tashkiney pegmatite vein is similar to Ilixin,but lies in the gneisses of the Olkhon series.It shows high concentrations of Be,Nb,Ta,as well as W,Sn,but lacks Li and F,due to a greater depth and higher temperature of the melt crystallization of this pegmatite.

Significance of“Printing English”in the Curriculum Setting of Business English Majors(Publishing Direction)

With the development of the global economy and the quick growth of international exchanges,Business English major plays an increasingly important role in higher education.The training goal of Business English major(publishing direction)has gradually shifted from the improvement of studentslanguage abilities to the cultivation of more specialized business knowledge and publishing skills.As an important course for Business English majors(publishing direction),Printing English is of great significance for cultivating studentsprofessional quality,professional competitiveness,career development,and practical ability.From the perspective of curriculum setting,it is necessary to re-understand the importance of Printing English in the curriculum setting of Business English major(publishing direction),and put forward corresponding teaching methods and strategies.

Phase-Based Optical Flow Method with Optimized Parameter Settings for Enhancing Displacement Measurement Adaptability

To enhance the applicability and measurement accuracy of phase-based optical flow method using complex steerable pyramids in structural displacement measurement engineering applications, an improved method of optimizing parameter settings is proposed. The optimized parameters include the best measurement points of the Region of Interest (ROI) and the levels of pyramid filters. Additionally, to address the issue of updating reference frames in practical applications due to the difficulty in estimating the maximum effective measurement value, a mechanism for dynamically updating reference frames is introduced. Experimental results demonstrate that compared to representative image gradient-based displacement measurement methods, the proposed method exhibits higher measurement accuracy in engineering applications. This provides reliable data support for structural damage identification research based on vibration signals and is expected to broaden the engineering application prospects for structural health monitoring.

Designing a Protection Scheme in Micro-Grid Systems with DG Using Central Protection Unite and Multiple Setting Group Protection Relays

Distributed generators now is widely used in electrical power networks, in some cases it works seasonally, and some types works at special weather conditions like photo voltaic systems and wind energy, and due to this continuous changes in generation condition, the fault current level in network will be affected, this changes in fault current level will affect in the coordination between protection relays and to keep the coordination at right way, an adaptive protection system is required that can adaptive its setting according to generation changes, the fault current level in each case is evaluated using ETAP software, and the required relay setting in each case is also evaluated using Grey Wolf Optimizer (GWO) algorithm, and to select suitable setting which required in each condition, to select the active setting group of protection relay according to generation capacity, central protection unite can be used, and to improve protection stability and minimizing relays tripping time, a proposed method for selecting suitable backup relay is used, which leads to decrease relays tripping time and increase system stability, output settings for relays in all cases achieved our constrains.

Carbonatites and Alkaline Igneous Rocks in Post-Collisional Settings:Storehouses of Rare Earth Elements

The rare earth elements(REE)are critical raw materials for much of modern technology,particularly renewable energy infrastructure and electric vehicles that are vital for the energy transition.Many of the world's largest REE deposits occur in alkaline rocks and carbonatites,which are found in intracontinental,rift-related settings,and also in syn-to post-collisional settings.Post-collisional settings host significant REE deposits,such as those of the Mianning-Dechang belt in China.This paper reviews REE mineralization in syn-to post-collisional alkaline-carbonatite complexes worldwide,in order to demonstrate some of the key physical and chemical features of these deposits.We use three examples,in Scotland,Namibia,and Turkey,to illustrate the structure of these systems.We review published geochemical data and use these to build up a broad model for the REE mineral system in post-collisional alkaline-carbonatite complexes.It is evident that immiscibility of carbonate-rich magmas and fluids plays an important part in generating mineralization in these settings,with REE,Ba and F partitioning into the carbonate-rich phase.The most significant REE mineralization in post-collisional alkaline-carbonatite complexes occurs in shallow-level,carbothermal or carbonatite intrusions,but deeper carbonatite bodies and associated alteration zones may also have REE enrichment.

Geochemistry and Sr,Nd Istopes of Granitoids from the Lac Ifni Area(Sirwa Massif-Anti-Atlas Morocco):A Geodynamic Setting for the Post-collisional Ediacaran Magmatic Chain of the Anti-Atlas

The plutonic rocks of the westernmost part of the Sirwa massif belong to the Ediacaran post-collisional magmatic chain of the Anti-Atlas.The geochemistry of major and trace elements attests that the fractional crystallization cannot account for the variations between the granitoids and the associated MME.They represent two contemporaneous but independent magmatic tendencies.However,Sr and Nd configur data argue for a similar and juvenile material

VR环境下SET GO教学法的构建及在耳鼻喉临床教学的应用

SET GO教学法也称为应诊录像教学法,就是在教学过程中,通过观察操作者的视频录像,进行教学的教学法。由于耳、鼻、喉的结构复杂,内部空间狭小,增加了视频录制的难度。在此背景下,吉林药学院附属医院将VR技术融入SET GO教学法中,借助VR技术录制成三维视频,使录制的视频清晰度更高,为SET GO教学法的实施提供了可行性。具体的教学环节分为前期教学、VR模拟操作及录制、VR录像加工、See和Else教学环节、Think教学环节、Goals和Offers教学环节等。通过以上环节的有序实施,提高了耳鼻喉科的临床教学效果。如在视频录制质量评价和SET GO教学效果评价方面,学生各项指标评价的良好率均在90%以上。建议进一步推广和应用。

Delivering substance use prevention interventions for adolescents in educational settings:A scoping review

Currently,a proportion of adolescents use alcohol,tobacco,and illicit drugs,which inevitably harms their health and academic progress.Adolescence is a peak period for substance use initiation and a critical time for preventing substance use problems.Various entities,such as families,schools,and communities,have implemented a variety of interventions to alleviate adolescent substance use problems,and schools play a unique role.To explore the types,characteristics,and effectiveness of substance use interventions in educational settings for adolescents,we conducted a scoping review and identified 32 studies after screening.We divided the 32 studies according to intervention type,including curriculum interventions focusing on cognitive-behavioral skill enhancement,exercise interventions,peer interventions and family-school cooperation,and electronic interventions.Except for the mixed results on electronic interventions,the results showed that the other interventions were beneficial to different extents in alleviating adolescent substance use problems.In addition,we analyzed and summarized the advantages and challenges of intervening in adolescent substance use in educational settings.Schools can use equipment and human resources to provide adolescents with various types of intervention measures,but they also face challenges such as stigmatization,ineffective coordination among multiple resources,and poor implementation effects.In the future,school-based intervention measures can fully utilize big data and artificial intelligence technology and collaborate with families and communities to intervene appropriately while paying attention to the comorbidity risks of substance use disorders and psychological health issues.

Geodynamic Development of Eurasian Active Margin during Closing of Thetys Ocean, Depending on the Scale of Mantle-Crustal Sources Influence at Pre- and Post-collision Settings, Controlled by Geological and Geochemical Indicators

Phanerozoic geodynamic evolution development of Tethys Ocean,its collision and closing,revealed at the Eurasian active margin in pre-and post-collision stages during convergence of Afro-Arabian and Eurasian continents.Subduction of oceanic slab under continental margin revealed in steady state subduction and steepening of subducting slab provoked the incursion of mantle diapir.The steady state subduction is related with island arc setting whereas steepening provoked incursion of mantle diaper interarc-backarc and minor ocean settings.They are controlled by geological indicators—volcagenic,petrochemical,geochemical,tectonic and metallogenic.Each of them is determined by scale of mantle-crustal influence,controlled by intensity and level of mantle diapir incursion in the crust rising from interarc-backarc to minor oceanic setting.The island arc setting is characterized by blocking,which as others by extension of rifting(interarc-backarc)caused spreading out from zone of volcanic activity and mineralization sialic crusts,whereas minor ocean setting caused by spreading out from zone of volcanic activity and mineralization sialic and basaltic crusts.So mantle crustal influence rising from island arc to minor ocean settings controlled type of volcanism and mineralization in pre-collision development.At the closing of ocean occurred the precollision setting which is transferred in post-collision revealed in orogenesis.It is divided in two stages.The first initial stage occurred in penetration hot fluids from the mantle in sialic crust smelted from in granitoid melt and leached the gold and trace melts Sb,W,Mg and Hg from sialic crust.The latter are geochemical indicators of post-collision setting.The second final stage revealed in shoshonite-basalt volcanism activity occurred with penetrated mantle material into deep volcanic chambers and characterized with increasing of mantle influence than initial stage of post-collision activity.

SETD5介导AKT1磷酸化调控结肠癌细胞的迁移和5-FU敏感性

目的:探讨含SET结构域蛋白5(SETD5)对结肠癌细胞增殖、迁移和对5-氟尿嘧啶(5-FU)药物敏感性的影响及机制。方法:常规培养结肠癌细胞,用Lipofectamine 2000将siSETD5-NC、si-SETD5-1~3质粒转染至HT-29细胞中,将其分为对照组(未处理)、si-SETD5-NC组、si-SETD5组和si-SETD5+SC79组,si-SETD5+SC79组HT-29细胞转染质粒的同时用10µmol/L SC79处理。qPCR法检测NCM460、HT-29和LoVo细胞中SETD5 mRNA表达,流式细胞术、细胞划痕法、WB法和CCK-8法分别检测各组HT-29细胞的凋亡情况、迁移能力、相关蛋白的表达,以及对5-FU的敏感性。结果:SETD5 mRNA在HT-29、LoVo细胞中均呈高表达(均P<0.01)。在HT-29细胞中成功地敲减了SETD5 mRNA(P<0.01)。敲减SETD5 mRNA可明显抑制HT-29细胞的增殖活性(P<0.01)、迁移能力(P<0.01)、相关蛋白(SETD5、p-PI3K、p-AKT1、p-mTOR蛋白)的表达(均P<0.01)、促进细胞凋亡(P<0.01),且提高其对5-FU的敏感性(P<0.01),这些作用均可被AKT激活剂SC79部分阻挡(P<0.05或P<0.01)。结论:SETD5在HT-29、LoVo细胞中高表达,SETD5通过PI3K/AKT1通路促进结肠癌HT-29细胞的增殖、迁移,且降低其对5-FU的敏感性,SETD5是结肠癌临床诊断、治疗的潜在靶点。

基于SET-AHP-TRIZ的坐式康复训练器设计研究

为解决现有坐式康复训练器形式与功能单一、操作使用缺乏智能化等问题,文章构建了基于SET-AHP-TRIZ的设计思路。首先,对产品的现状、用户进行市场调研,采用SET分析法确定目标产品的机会缺口;其次,应用AHP法对需求点进行定量计算,以确定创新过程中需要着重改善的问题;最后,通过应用TRIZ理论分析出现的矛盾问题,并总结其矛盾类型,利用发明原理解决问题,进行坐式康复训练器设计实践,减少了设计过程主观因素的影响,使设计结果更为科学合理,以期提高用户的满意度。

Psychosocial Group Intervention at a Low-Resource Setting Environment for Women Who Are Diagnosed and Treated for Breast Cancer: A Systematic Review

Africa faces significant challenges in terms of material and personnel resources for oncology interventions. This is particularly evident in South Africa, where resources are divided into high- and low-resource settings. High-resource settings cater to those with financial means to access private oncology facilities. However, many breast cancer patients receive care in South Africa’s low-resource settings, such as public hospital oncology clinics. Unfortunately, these settings have limited service providers and fail to offer comprehensive interventions, resulting in poor outcomes. However, recent research has highlighted the significance of socially supportive relationships in promoting healing and overall individual well-being, and spirituality has been identified as a source of positive outcomes in cancer patients. This systematic review paper explores the feasibility of implementing support group cancer care and interventions that incorporate social support networks available in community settings, and spiritual practices facilitated by traditional healers, and religious/spiritual leaders. These interventions can be provided within low-resource settings to women diagnosed with breast cancer. Inclusive participation of spouses, children, and extended family in the support group cancer care can facilitate healing for the entire system. Focusing on the strengths and resources within communities and incorporating these complementary services, can enhance the well-being and quality of life for Black African women diagnosed with breast cancer, despite low-resource settings. This approach acknowledges the potential of community-based support networks and encourages collaboration between various stakeholders, including community health educators, nurses, lay counselors, and community volunteers, to address the complex needs of these patients.

Magma source and tectonic setting of the Dunde granite in the Western Tianshan:constraints from geochronology,geochemistry,and Sr–Nd–Hf isotopes

The Dunde iron-zinc polymetallic deposit is one of large iron deposits occurred in the Awulale Metallogenetic Belt,Western Tianshan(NW-China).This study reports new geochronology and geochemistry for granite in the Dunde mining area in order to constrain the tectonicmagmatic activities and metallogenesis of this region.Granites in the southwest of Dunde mining area are mainly syenogranites intruded into volcanics of the Dahalajunshan Formation in the Early Carboniferous,and they are far from the area where ore bodies and mineralized altered rocks are widely developed.LA-ICP-MS U–Pb zircon dating indicates that Dunde syenogranite was at 306.8±1.0 Ma,which could constrain the upper limit of metallogenic age for this deposit.The Dunde granites are high SiO_(2)(73.41–80.07 wt%),high differentiation index(D.I.=89.7–95.0),weakly peraluminous to metaluminous(A/CNK=0.94–1.08),and they are enriched in LILE and LREE and depleted in Eu,Ba,Sr and P_(2)O_(5),indicating that they belong to highly fractionated Ⅰ-type granite.Based on εHf values(+9.2 to+10.5)for zircon and high εNd(-t)values(+4.7 to+5.8)for whole-rock,and the two-stage model ages for 601–735 Ma,suggest that the magma source could be the juvenile lower crust.Combined with regional geological setting,the 306.8 Ma Dunde granites are formed in post-collision extensional tectonic setting.