The late Early-Paleozoic granitic magmatism in Northwestern Fujian, China: constraints on intraplate orogeny in the South China block

The Early Paleozoic tectono-thermal event was a significant orogenic activity during the Phanerozoic era,which had a profound impact on the early crust of the South China Block(SCB) and established the foundation for later tectonic activity.The Wuyi-Yunkai orogenic belt in Southeastern China was extensively exposed to Early Paleozoic magmatism,the genetic mechanism of which remains controversial.To shed light on this issue,detailed petrological,geochemical,and zircon U-Pb-Hf isotopic studies were carried out on two granitoids,namely the Yuntongshan pluton and the Gaoqiao pluton,identified in the central Wuyishan.Zircon U-Pb chronology of the Yuntongshan and Gaoqiao bodies yielded ages of437±4 Ma(MSWD=2.2) and 404±2 Ma(MSWD=12),respectively,indicating that they were emplaced during the Early Silurian and Early Devonian periods.These granitoids are primarily composed of biotite-granite and biotite-monzonitic-granites,with high concentrations of S_(i)O_(2)(73.59-75.91 wt%),K_(2)O+Na_(2)O(8.31-8.73wt%),and low contents of MgO,CaO,Cr,Ni.They are classified as high-K calc-alkaline and weakly metaluminous-strongly peraluminous S-type granites.These granitoids are enriched in light rare earth elements(LREEs) and large ion lithophile elements(LILEs) and depleted in heavy rare earth elements(HREEs) and high field strength elements(HFSEs) with arc affinity.The εHf(t) values of-3.3 to-15.4 with two-stage Hf model ages ranging from 2829 to 1644 Ma,combined with the presence of Neoproterozoic inherited zircons,suggest that the primary magma of these granitoids was derived from the partial melting of Neoproterozoic crust with a Paleoproterozoic crustal model age.These findings,combined with the spatio-temporal distribution of regional magmatism,reveal that the late Early-Paleozoic granitoids formed in the intraplate orogenic background originating from the subduction of the proto-Tethys Ocean and proto-Pacific Ocean around the margin of the east Gondwana supercontinent.

Biogeochemistry of sedimentary organic matter in the Yongjiang River estuary in the southern part of Hangzhou Bay,China,since the Late Pleistocene

A sediment core(YJK19-02)collected from the southern outlet of Hangzhou Bay near the Yongjiang River estuary in East China was analyzed for grain size,lignin,bulk elemental composition,stable carbon isotope,and rare earth elements(REEs)to determine the sources and diagenesis of sedimentary organic matter(OM)of the estuary and adjacent areas since the Late Pleistocene.δ^(13)C values(-24.80‰–-23.60‰),total organic carbon/total nitrogen(TOC/TN)molar ratios(8.00–12.14),and light rare earth element/heavy rare earth element ratios(LREE/HREE=8.34–8.91)revealed the predominance of terrestrial sources of OM,mainly from the Changjiang(Yangtze)River.The lignin parameters of syringyl/vanillyl(S/V=0.20–0.73)and cinnamyl/vanillyl(C/V=0.03–0.19)ratios indicate the predominance of nonwoody angiosperms,and the vanillic acid/vanillin ratios[(Ad/Al)_(V)=0.32–1.57]indicate medium to high degrees of lignin degradation.An increasing trend ofΛ(total lignin in mg/100-mg OC)values from ca.14500 a BP to ca.11000 a BP reflected the increase in temperature during the Late Pleistocene.However,a time lag effect of temperature on vegetation abundance was also revealed.The relatively higher and stableΛvalues correspond to the higher temperature during the mid-Holocene from ca.8500 a BP to ca.4500 a BP.Λvalues decreased from ca.4000 a BP to the present,corresponding to historical temperature fluctuations during this time.Our results show that the vegetation abundance in the Yongjiang River Basin since the Late Pleistocene was related to the temperature fluctuation duo to climate change.

Evaluation of Some Treatment Options Inlate and Neglected Hip Fractures Using the Modified Harris Hip Score

Background: The choice of the appropriate operative intervention in patients with late and neglected hip fracture continuous to be a huge dilemma for orthopedic surgeons. Purpose: To evaluate the satisfaction or otherwise of some treatment options using the modified Harris-hip score (HHS) in resource poor setting. Materials and Methods: A retrospective cross-sectional study conducted at ATBUTH, Bauchi. Data of 60 patients over the age of 18 years with hip fractures (femoral neck, intertrochanteric and sub trochanteric fractures) who had operative intervention between 1st September 2019 and 31st August 2020 with cannulated screws, Proximal femur lock compression plate (PFLCP), cementlessor cemented bipolar hemiarthroplasty (BHA). Results: The mean age of studied patients was 65.7 ± 16.1 years, with age ranging from 19 - 101 years. M:F ratio was 1.2:1 across all age groups and 1:1.4 amongst those >60 years. 51 patients (85%) presented > 1 week after injury with 24 patients (40%) sustaining hip fractures from low energy trivial indoor fall and 28 patients (46.7%) mostly younger sustaining fractures from high energy motor vehicular accident (MVA). The prevalence rate for femoral neck, intertrochanteric and subtrochanteric fractures were 32 (53.3%), 17 (28.3%) and 11 (18.3%) respectively. From the data retrieved, 21patients (35.0%), 17 patients (28.3%), 20 patients (33.3%) and 2 patients (3.3%) had PFLCP, cemented BHA, cementless BHA and cannulated screw fixation respectively. Most (66.7%) of those who had PFLCP achieved satisfactory radiologic union and there was also 94.1% and 85% satisfactory outcome rate amongst the patients with cemented BHA and cementless BHA respectively. Irrespective of the operative intervention method at 1 year follow-up, there was a statistically significant improvement in post-operative HHS (P value 0.02), with 83.4% having good to excellent results. Conclusion: There is highrate of late and neglected hip fracture in our environment. Satisfactory outcome with statistically significant improvement in Post-operative HHS was achieved in patients treated for hip fractures.

A Comparison between Late Preterm and Term Infants with Respiratory Distress Syndrome, Early-Onset Sepsis, and Neonatal Jaundice in Ecuadorian Newborns

Background: To examine the differences in prevalence of respiratory distress syndrome, early-onset sepsis and jaundice, between late preterm infants versus term infants in Ecuadorian newborns. Methods: Study design: Epidemiological, observational, and cross-sectional, with two cohorts of patients. Settings: IESS Quito Sur Hospital at Quito, Ecuador, from February to April of 2020. Participants: This study included 204 newborns, 102 preterm infants, 102 term infants. Results: There are significant differences between late preterm infants and term infants, with a p-value of 0.000 in the prevalence of early sepsis, 70.59% vs. 35.29%. In respiratory distress syndrome between late and term premature infants, significant differences were observed with a p-value of 0.000, the proportion being 55.58% vs. 24.51% respectively. The prevalence of jaundice is higher in term infants with a p value of 0.002, 72.55%, versus 51.96% in late preterm infants, and the mean value of bilirubins in mg/dL was higher in term infants 14.32 versus 12.33 in late preterm infants;this difference is statistically significant with a p value of 0.004. Admission to the NICU is more frequent in late preterm infants with a p-value of 0.000, being 42.16% for late preterm infants vs. 7.84% in term infants;the mean of the hospital days with p-value 0.005, was higher in late preterm infants 4.97 days vs. 3.55 days for term newborns. Conclusion: Due to the conditions of their immaturity, late preterm infants are 2.86 times more likely to present early sepsis than full-term newborns. It is shown that late preterm infants are 2.69 times more likely to have respiratory distress syndrome compared to term infants, therefore, late preterm infants have a longer hospital stay of 4.97 days versus 3.55 days in term infants. Jaundice and mean bilirubin levels are higher in term infants due to blood group incompatibility and insufficient breastfeeding.

Impaired implicit emotion regulation in patients with panic disorder:An event-related potential study on affect labeling

BACKGROUND Panic disorder(PD)involves emotion dysregulation,but its underlying mechanisms remain poorly understood.Previous research suggests that implicit emotion regulation may play a central role in PD-related emotion dysregulation and symptom maintenance.However,there is a lack of studies exploring the neural mechanisms of implicit emotion regulation in PD using neurophysiological indicators.AIM To study the neural mechanisms of implicit emotion regulation in PD with eventrelated potentials(ERP).METHODS A total of 25 PD patients and 20 healthy controls(HC)underwent clinical evaluations.The study utilized a case-control design with random sampling,selecting participants for the case group from March to December 2018.Participants performed an affect labeling task,using affect labeling as the experimental condition and gender labeling as the control condition.ERP and behavioral data were recorded to compare the late positive potential(LPP)within and between the groups.RESULTS Both PD and HC groups showed longer reaction times and decreased accuracy under the affect labeling.In the HC group,late LPP amplitudes exhibited a dynamic pattern of initial increase followed by decrease.Importantly,a significant group×condition interaction effect was observed.Simple effect analysis revealed a reduction in the differences of late LPP amplitudes between the affect labeling and gender labeling conditions in the PD group compared to the HC group.Furthermore,among PD patients under the affect labeling,the late LPP was negatively correlated with disease severity,symptom frequency,and intensity.CONCLUSION PD patients demonstrate abnormalities in implicit emotion regulation,hampering their ability to mobilize cognitive resources for downregulating negative emotions.The late LPP amplitude in response to affect labeling may serve as a potentially valuable clinical indicator of PD severity.

Early proactive monitoring of DNA-thioguanine in patients with Crohn’s disease predicts thiopurine-induced late leucopenia in NUDT15/TPMT normal metabolizers

BACKGROUND Thiopurine-induced leucopenia significantly hinders the wide application of thiopurines.Dose optimization guided by nudix hydrolase 15(NUDT15)has significantly reduced the early leucopenia rate,but there are no definitive biomarkers for late risk leucopenia prediction.AIM To determine the predictive value of early monitoring of DNA-thioguanine(DNATG)or 6-thioguanine nucleotides(6TGN)for late leucopenia under a NUDT15-guided thiopurine dosing strategy in patients with Crohn’s disease(CD).METHODS Blood samples were collected within two months after thiopurine initiation for detection of metabolite concentrations.Late leucopenia was defined as a leukocyte count<3.5×10^(9)/L over two months.RESULTS Of 148 patients studied,late leucopenia was observed in 15.6%(17/109)of NUDT15/thiopurine methyltransferase(TPMT)normal and 64.1%(25/39)of intermediate metabolizers.In patients suffering late leucopenia,early DNATG levels were significantly higher than in those who did not develop late leucopenia(P=4.9×10^(-13)).The DNATG threshold of 319.43 fmol/μg DNA could predict late leucopenia in the entire sample with an area under the curve(AUC)of 0.855(sensitivity 83%,specificity 81%),and in NUDT15/TPMT normal metabolizers,the predictive performance of a threshold of 315.72 fmol/μg DNA was much more remarkable with an AUC of 0.902(sensitivity 88%,specificity 85%).6TGN had a relatively poor correlation with late leucopenia whether in the entire sample(P=0.021)or NUDT15/TPMT normal or intermediate metabolizers(P=0.018,P=0.55,respectively).CONCLUSION Proactive therapeutic drug monitoring of DNATG could be an effective strategy to prevent late leucopenia in both NUDT15/TPMT normal and intermediate metabolizers with CD,especially the former.

Clinical characteristics of patients with early-and late-onset optic neuromyelitis optica spectrum disease

Objective:To analyze the different clinical features of patients with early-onset(EO-NMOSDs)and late-onset neuromyelitis optica spectrum diseases(LO-NMOSDs).Methods:A total of 51patients with neuromyelitis optica spectrum disease who were diagnosed in our hospital for the first time from January 2015 to December 2022 were included in the First Affiliated Hospital of Hainan Medical College and divided into 22 cases in the EO-NMOSDs group and 29 cases in the LO-NMOSDs group according to whether the age of onset was 50 years old.The basic data,Extended Disability Status Scale(EDSS)score,blood and cerebrospinal fluid test indicators of the two groups were statistically analyzed.Results:There were no significant differences in demographic characteristics,clinical features and serum AQP-4 antibody positivity rate between the two groups(all P>0.05),and there were significant differences in triglycerides(TG),low-density lipoprotein(LDL),apolipoprotein A(APOA),apolipoprotein B(APOB)and lipoprotein a(P=0.010,P=0.048,P=0.014,P=0.061,P=0.001,respectively),and cerebrospinal fluid LDH,There were significant differences between microprotein quantification and EDSS score(P=0.018,P=0.034,P=0.025,respectively),and the level of microprotein quantification in cerebrospinal fluid of LO-NMOSDs had a certain correlation with the degree of disability(r=0.52,P<0.03).Conclusion:LO-NMOSDs and EO-NMOSDs group patients have similar demographic characteristics,serum AQP-4 antibody positive rate and clinical features,but compared with EO-NMOSDs,patients in LO-NMOSDs group are prone to abnormal lipid metabolism,higher trace proteins in cerebrospinal fluid and more likely to be disabled,and among LO-NMOSDs,the higher the trace protein in the cerebrospinal fluid,the more severe the disability status of patients.

Trajectory of Walking Function in Late-Stage Older Individuals Managed with a Regular Exercise Program: A 5-Year Longitudinal Tracking with an IoT Gait Analysis System Using Accelerometers

Purpose: This study focused on maintaining and improving the walking function of late-stage older individuals while longitudinally tracking the effects of regular exercise programs in a day-care service specialized for preventive care over 5 years, using detailed gait function measurements with an accelerometer-based system. Methods: Seventy individuals (17 male and 53 female) of a daycare service in Tokyo participated in a weekly exercise program, meeting 1 - 2 times. The average age of the participants at the start of the program was 81.4 years. Gait function, including gait speed, stride length, root mean square (RMS) of acceleration, gait cycle time and its standard deviation, and left-right difference in stance time, was evaluated every 6 months. Results: Gait speed and stride length improved considerably within six months of starting the exercise program, confirming an initial improvement in gait function. This suggests that regular exercise programs can maintain or improve gait function even age groups that predictably have a gradual decline in gait ability due to enhanced age. In the long term, many indicators tended to approach baseline values. However, the exercise program seemingly counteracts age-related changes in gait function and maintains a certain level of function. Conclusions: While a decline in gait ability with aging is inevitable, establishing appropriate exercise habits in late-stage older individuals may contribute to long-term maintenance of gait function.

The Immediate Analgesic Effect and Impact on Gait Function of Transcutaneous Electrical Nerve Stimulation in Late-Stage Elderly Individuals with Knee Pain: Examination of Gait Function Using an IoT-Based Gait Analysis Device

Purpose: This study verified the effects of transcutaneous electrical nerve stimulation (TENS), which can be worn during walking and exercise, in elderly individuals with late-stage knee pain who exercise regularly. Methods: Thirty-two late-stage elderly individuals were evaluated for knee pain during rest, walking, and program exercises, with and without TENS. Gait analysis was performed using an IoT-based gait analysis device to examine the effects of TENS-induced analgesia on gait. Results: TENS significantly reduced knee pain during rest, walking, and programmed exercises, with the greatest analgesic effect observed during walking. The greater the knee pain without TENS, the more significant the analgesic effect of TENS. A comparison of gait parameters revealed a significant difference only in the gait cycle time, with a trend towards faster walking with TENS;however, the effect was limited. Conclusion: TENS effectively relieves knee pain in late-stage elderly individuals and can be safely applied during exercise. Pain management using TENS provides important insights into the implementation of exercise therapy in this age group.

Mesozoic-Cenozoic Basin Features and Evolution of Southeast China

The Late Triassic to Paleogene （T3-E） basin occupies an area of 143100 km^2, being the sixth area of the whole of SE China; the total area of synchronous granitoid is about 127300 km^2; it provides a key for understanding the tectonic evolution of South China. From a new 1：1500000 geological map of the Mesozoic-Cenozoic basins of SE China, combined with analysis of geometrical and petrological features, some new insights of basin tectonics are obtained. Advances include petrotectonic assemblages, basin classification of geodynamics, geometric features, relations of basin and range. According to basin-forming geodynamical mechanisms, the Mesozoic-Cenozoic basin of SE China can be divided into three types, namely： 1） para-foreland basin formed from Late Triassic to Early Jurassic （T3-J1） under compressional conditions; 2） rift basins formed during the Middle Jurassic （J2） under a strongly extensional setting; and 3） a faulted depression formed during Early Cretaceous to Paleogene （K1-E） under back-arc extension action. From the rock assemblages of the basin, the faulted depression can be subdivided into a volcanic-sedimentary type formed mainly during the Early Cretaceous （K1） and a red -bed type formed from Late Cretaceous to Paleogene （K2-E）. Statistical data suggest that the area of all para-foreland basins （T3-J1） is 15120 km^2, one of rift basins （J2） occupies 4640 km^2, and all faulted depressions equal to 124330 km^2 including the K2-E red-bed basins of 37850 km^2. The Early Mesozoic （T3-J1） basin and granite were mostly co-generated under a post-collision compression background, while the basins from Middle Jurassic to Paleogene （J2-E） were mainly constrained by regional extensional tectonics. Three geological and geographical zones were surveyed, namely： 1） the Wuyishan separating zone of paleogeography and climate from Middle Jurassic to Tertiary; 2） the Middle Jurassic rift zone; and 3） the Ganjiang separating zone of Late Mesozoic volcanism. Three types of basin-granite relationships have been identified, including compressional （a few）, strike-slip （a few）, and extensional （common）. A three-stage geodynamical evolution of the SE-China basin is mooted： an Early Mesozoic basin-granite framework; a transitional Middle Jurassic tectonic regime; intracontinental extension and red-bed faulted depressions since the Late Cretaceous.

Structure Styles of Mesozoic-Cenozoic U-bearing Rock Series in Northern China

In Northern China, sandstone-type uranium （U） deposits are mostly developed in Mesozoic-Cenozoic basins. These U deposits are usually hosted in unvarying horizons within the basins and exhibit typical U-forming sedimentary associations, which is referred to as U-bearing rock series. This study describes the structural features of U-bearing rock series within the main Mesozoic-Cenozoic U-producing continental basins in Kazakhstan, Uzbekistan, and Russia in the western segment of the Central Asian Metallogenic Belt （CAMB）, and Northern China in the eastern segment of the CAMB. We analyze the basic structural conditions and sedimentary environments of U-bearing rock series in Northern China and classify their structural styles in typical basins into river valley, basin margin, and intrabasin uplift margin types. The intrabasin uplift margin structural style proposed in this study can be used to indicate directions for the exploration of sandstone-type U deposits hosted in the center of a basin. At the same time, the study of structural style provides a new idea for exploring sandstone-type U deposits in Mesozoic-Cenozoic basins and it is of great significance to prospecting of sandstone-type uranium deposits.

Mesozoic-Cenozoic Tectonics of the Yellow Sea and Oil-Gas Exploration

The purpose of the present study was to study the tectonics of the Yellow Sea. Although oilgas exploration has been undertaken for more than 30 years in the southern Yellow Sea, the exploration progress has achieved little. There are three tectonic periods with near N-S trending shortening and compression （260-200 Ma, 135-52 Ma and 23-0.78 Ma） and three tectonic periods with near E-W trending shortening and compression （200-135 Ma, 52--23 Ma and 0.78 Ma） at the Yellow Sea and adjacent areas during the Mesozoic and Cenozoic. The lndosinian tectonic period is the collision period between the Sino-Korean and Yangtze Plates, which formed the basic tectonic framework for the Yellow Sea area. There were strong intraplate deformations during the Yanshanian （200-135 Ma） and Sichuanian （135-52 Ma） periods with different tectonic models, which are also the main formation periods for endogenic metallic mineral deposits around the Yellow Sea. The three tectonic periods during the Cenozoic affect important influences for forming oil-gas reservoirs. The Eocene-Oligocene （52-23 Ma） is the main forming period for oil-gas sources. The Miocene-Early Pleistocene （23-0.78 Ma） was a period of favorable passage for oil-gas migration along NNE trending faults. Since the Middle Pleistocene （0.78 Ma） the NNE trending faults are closed and make good conditions for the reservation of oil-gas. The authors suggest that we pay more attention to the oil-gas exploration at the intersections between the NNE trending existing faults and Paleogene- Neogene systems in the southern Yellow Sea area.

Geochemistry of Rare Earth Elements of Mesozoic-Cenozoic Sandstones in North Margin of Dabie Mountains and Adjacent Areas: Constraints to Source Rocks

Based on the study of REE in Mesozoic-Cenozoic sandstones, the paper indicates that Jurassic Fanghushan and Yuantongshan Formations and Lower Cretaceous Zhougongshan Formation have ∑REE of 157 μg·g^(-1), δ_(Eu) of 0.69 and (La/Yb)_N of 11.1, which are similar to the Foziling and Luzhenguan Groups, and it implies that the latter may be the source rocks of the former. The Sanjianpu and Heishidu Formations have high REE concentrations (∑REE=264.8 μg·g^(-1), 328.2 μg·g^(-1) respectively), high Eu anomaly (δ_(Eu)=0.57, 0.67 respectively) and lower Eu/Sm ratios (0.18～0.19), which differs from existent metamorphic rocks in the Dabie Mountains, so where their source rocks came from remains to be studied. The REE features of the Zhengyangguan Formation can be comparable to the Dabie complex and Luzhenguan Group, which shows that the Dabie complex had suffered unroofing in Neocene and constituted the source rocks. Mesozoic sandstones in Huainan area have lower REE concentrations (∑REE=80.9 μg·g^(-1)), high Eu anomaly (δ_(Eu)=0.66) and (La/Yb)_N of 5.7, and it indicates that their source rocks may not come from the Dabie Mountains.

Predictors of early and late hepatocellular carcinoma recurrence

Hepatocellular carcinoma(HCC)is the most frequent liver neoplasm,and its incidence rates are constantly increasing.Despite the availability of potentially curative treatments(liver transplantation,surgical resection,thermal ablation),long-term outcomes are affected by a high recurrence rate(up to 70%of cases 5 years after treatment).HCC recurrence within 2 years of treatment is defined as“early”and is generally caused by the occult intrahepatic spread of the primary neoplasm and related to the tumor burden.A recurrence that occurs after 2 years of treatment is defined as“late”and is related to de novo HCC,independent of the primary neoplasm.Early HCC recurrence has a significantly poorer prognosis and outcome than late recurrence.Different pathogenesis corresponds to different predictors of the risk of early or late recurrence.An adequate knowledge of predictive factors and recurrence risk stratification guides the therapeutic strategy and post-treatment surveillance.Patients at high risk of HCC recurrence should be referred to treatments with the lowest recurrence rate and when standardized to combined or adjuvant therapy regimens.This review aimed to expose the recurrence predictors and examine the differences between predictors of early and late recurrence.

Late sowing enhances lodging resistance of wheat plants by improving the biosynthesis and accumulation of lignin and cellulose

Delayed sowing mitigates lodging in wheat. However, the mechanism underlying the enhanced lodging resistance in wheat has yet to be fully elucidated. Field experiments were conducted to investigate the effects of sowing date on lignin and cellulose metabolism, stem morphological characteristics, lodging resistance, and grain yield. Seeds of Tainong 18,a winter wheat variety, were sown on October 8(normal sowing) and October 22(late sowing) during both of the 2015–2016 and 2016–2017 growing seasons. The results showed that late sowing enhanced the lodging resistance of wheat by improving the biosynthesis and accumulation of lignin and cellulose. Under late sowing, the expression levels of key genes(Ta PAL, Ta CCR, Ta COMT, TaCAD, and TaCesA1, 3, 4, 7, and 8) and enzyme activities(TaPAL and TaCAD) related to lignin and cellulose biosynthesis peaked 4–12 days earlier, and except for the TaPAL, TaCCR, and TaCesA1 genes and TaPAL, in most cases they were significantly higher than under normal sowing. As a result, lignin and cellulose accumulated quickly during the stem elongation stage. The mean and maximum accumulation rates of lignin and cellulose increased, the maximum accumulation contents of lignin and cellulose were higher, and the cellulose accumulation duration was prolonged. Consequently, the lignin/cellulose ratio and lignin content were increased from 0 day and the cellulose content was increased from 11 days after jointing onward. Our main finding is that the improved biosynthesis and accumulation of lignin and cellulose were responsible for increasing the stem-filling degree, breaking strength, and lodging resistance. The major functional genes enhancing lodging resistance in wheat that are induced by delayed sowing need to be determined.

Geochronology,Petrogenesis and Tectonic Setting of the Late Jurassic I-type Granites in the North Qinling Orogenic Belt,Central China

The North Qinling Orogenic Belt(NQOB)is a composite orogenic belt in central China.It started evolving during the Meso-Neoproterozoic period and underwent multiple stages of plate subduction and collision before entering intra-continental orogeny in the Late Triassic.The Meso-Cenozoic intra-continental orogeny and tectonic evolution had different responses in various terranes of the belt,with the tectonic evolution of the middle part of the belt being particularly controversial.The granites distributed in the Dayu and Kuyu areas in the middle part of the NQOB can provide an important window for revealing the geodynamic mechanisms of the NQOB.The main lithology of Dayu and Kuyu granites is biotite monzogranite,and the zircon U-Pb dating yielded intrusive ages of 151.3±3.4 Ma and 147.7±1.5 Ma,respectively.The dates suggest that the biotite monzogranite were formed at the end of the Late Jurassic.The whole-rock geochemistry analysis shows that the granites in the study areas are characterized by slightly high SiO_(2)(64.50-68.88 wt%)and high Al_(2)O_(3)(15.12-16.24 wt%)and Na_(2)O(3.55-3.80 wt%)contents.They are also enriched in light rare earth elements,large ion lithophile elements(e.g.,Ba,K,La,Pb and Sr),and depleted in high field strength elements(HFSEs)(e.g.,Ta,Nb,P and Ti).Additionally,the granites have weakly negative-slightly positive Eu anomalies(δEu=0.91-1.19).Zircon Lu-Hf isotopic analysis showedε_(Hf)(t)=-6.1--3.8,and the two-stage model age is T_(2DM(crust))=1.5-1.6 Ga.The granites in the study areas are analyzed as weak peraluminous high-K calc-alkaline I-type granites.They formed by partial melting of the thickened ancient lower crust,accompanied by the addition of minor mantle-derived materials.During magma ascent,they experienced fractional crystallization,with residual garnet and amphibole for a certain proportion in the magma source region.Comprehensive the geotectonic data suggest that the end of the Late Jurassic granite magmatism in the Dayu and Kuyu areas represents a compression-extension transition regime.It may have been a response to multiple tectonic mechanisms,such as the late Mesozoic intra-continental southward subduction of the North China Craton and the remote effect of the Paleo-Pacific Plate subduction.

Palynological Evidence of Late Pleistocene Soft-sediment Deformation Event in the Northeastern Margin of the Tibetan Plateau

The northeastern margin of the Tibetan Plateau is the youngest part of the Tibetan Plateau where tectonic activity is intense and climate change is complex.In this study,combined with field investigations,we explored accelerator mass spectrometry 14C and optically stimulated luminescence dating and palynological analysis of the sedimentary sequence in the Qingshuihe Basin to explain the origin of soft-sediment deformation layer.Dating and palynological results from the Sanchahe section in the basin revealed a detailed history of vegetation variation and associated climate change from~18 to~5 ka BP.The results indicate that the permafrost developed at~18–11.7 ka BP,and the soft-sediment deformation structures formed at~11.7–5 ka BP.Together with the characteristics of the deformation(meter-scale,continuous symmetrical wave)and paleoclimate,we suggest that the soft-sediment deformation layer in the late Pleistocene was cryoturbated under climatic conditions.The discovery of a series of cryoturbations in the Qingshuihe Basin has further enriched the regional distribution of periglacial phenomena in the west of the Ordos Plateau,expanded the distribution range of periglacial phenomena,and provided evidence for exploring the temporal and spatial changes in permafrost in northern China at the end of the late Pleistocene.

Late Jurassic Volcanism Deduced from Geochemical,Geochronological,and Sr-Nd-Hf Isotopic Composition Characteristics of the Nanyuan Formation,South China

The Nanyuan Formation contains information related to the Mesozoic tectonic transformation.In this study,three representative profiles were surveyed from the Nanyuan Formation,and multiple analyses were conducted.Zircon U-Pb dating yielded their ages as approximately 158–146 Ma.The volcanic rocks are enriched in Rb,Th,U,K,and Pb and depleted in Nb,Ta,P,and Ti,implying their affinity for I-type granites.TheεNd(t)values(-8.3 to-6.0),^(87)Sr/^(86)Sr)i values(0.7077–0.7094)of the volcanic rock,andεHf(t)values(-8.71 to 0.12)of the Mesozoic zircons suggest that the Nanyuan Formation magma originated in the lower crust with the involvement of depleted mantle materials.The parent rocks of the rhyolitic and dacitic volcanic rocks formed by partial melting of basement rocks in South China and the andesitic volcanic rocks were derived from partial melting of the metasomatites generated by slab-mantle interaction.The fractional crystallization also played an important role in later stage.Discrimination diagrams of the volcanic rocks indicated that they formed in a volcanic arc environment.Combined with previous data,the Nanyuan Formation recorded subduction of the Paleo-Pacific Plate before regional tectonic transformation.The compressive stress field endured until the end of the Late Jurassic.

Petrogenesis of the Late Eocene to Early Oligocene Yao'an Shoshonitic Complex,Southeastern Tibet:Partial Melting of an Ancient Continental Lithospheric Mantle beneath the Yangtze Block

Cenozoic potassic-ultrapotassic igneous rocks are widespread in the southeastern Tibetan Plateau.Their petrogenesis and magmatic processes remain subject to debate in spite of numerous publications.Almost all of the Cenozoic extrusive and intrusive rocks in the Yao’an area,western Yunnan Province,SW China,are geochemically shoshonitic,collectively termed here the Yao’an Shoshonitic Complex(YSC).The YSC is located in the(south)easternmost part of the ENE-WSW-trending,~550 km-long and~250 km-wide Cenozoic magmatic zone;the latter separates the orthogonal and oblique collision belts of the India-Eurasia collision orogen.Previously published geochronological and thermochronological data revealed that the rocks of the YSC were emplaced over a short timespan of 34-32 Ma.This and our new data suggest that the primary magma of the YSC likely was formed by partial melting of ancient continental lithospheric mantle beneath the Yangtze Block.This part of the continental lithospheric mantle had likely not been modified by any oceanic subduction.Fractionation crystallization of an Mg-and Ca-bearing mineral and TiFe oxides during the magmatic evolution probably account for the variable lithologies of the YSC.

Logging interpretation method for reservoirs with complex pore structure in Mesozoic-Cenozoic faulted basin around Daqing exploration area

In Mesozoic-Cenozoic faulted basin in the periphery of Daqing exploration area, the clastic reservoirs mainly consist of siltstone and gravel-bearing sandstone. The electrical conductivity of the reservoirs is complicated due to the complex pore structures, which cannot be accurately interpreted with commonly used model. In order to solve the problem, a three-water model has been applied in this study based on in-depth analysis of the conductive mechanism of rocks in the explored area, and favorable application results are achieved.