Longevity of the Permian Emeishan mantle plume (SW China): 1 Ma, 8 Ma or 18 Ma?

After the formation of the ∼ 260 Ma Emeishan large igneous province, there were two volumetrically minor magmatic pulses at ∼ 252 Ma and ∼ 242 Ma, respectively. Alkaline mafic dykes intruding both 260 Ma and 252 Ma felsic plutons in the Panxi region, southwestern China, have compositions similar to the Emeishan flood basalts. One dyke is dated using the SHRIMP zircon U-Pb technique at 242 ± 2 Ma, ∼ 18 Ma younger than the start of Emeishan magmatism. The dykes have enriched light rare earth element patterns (La/YbN = 4.4-18.8) and trace element patterns similar to the Emeishan flood basalts and average ocean-island basalts. Some trace element ratios of the dykes (Zr/Nb = 3.8-8.2, La/Nb = 0.4-1.7, Ba/La = 7.5-25.6) are somewhat similar to EM1 source material, however, there are differences. Their εNd values (εNd = +2.6 and +2.7) and ISr( ISr = 0.704542 and 0.704554) ratios are indicative of a mantle source. Thus Emeishan magmatism may have lasted for almost 20 Ma after the initial eruption. However, geological evidence precludes the possibility that the post-260 Ma magmatic events were directly related to Emeishan magmatism, which began at and ended shortly after 260 Ma. The 252 Ma plutons and 242 Ma dykes represent volumetrically minor melting of the fossil Emeishan plume-head beneath the Yangtze crust. The 252 Ma magmatic event was likely caused by post-flood basalt extension of the Yangtze crust, whereas the 242 Ma event was caused by decompressional melting associated with the collision between the South China and North China blocks during the Middle Triassic. © 2008 Cambridge University Press.published_or_final_versio

Provenance and tectonic setting of the Neoproterozoic Yanbian Group, western Yangtze Block (SW China)

Tectonic evolution of the Yangtze Block of South China during Neoproterozoic time has been a major focus of debate and is important in the reconstruction of the Rodinian supercontinent. The Yanbian Group in the western margin of the Yangtze Block is a well-preserved Neoproterozoic volcanic-sedimentary sequence and provides a rare opportunity to examine the provenance and tectonic setting. It consists of a lower part composed of ∼1500 m thick basaltic lavas and an upper part of ∼3500 m thick flysch deposits. The flysch sequence contains typical deep marine turbidites consisting mainly of fine-grained volcaniclastic sandstones and mudstones, indicating a submarine fan depositional system. Detrital zircon dating yields ages ranging from ca. 865 Ma to 1000 Ma with two peaks at ca. 900 Ma and 920 Ma, respectively. The Yanbian Group is intruded by the ∼860 Ma Guandaoshan dioritic pluton, constraining its depositional age at ca. 870 Ma. The sandstones contain abundant feldspar and lithic fragments with minor amounts of quartz and have an average composition of Q 16F 35L 49, suggesting a proximal source and an undissected to transitional arc setting. The lithic fragments in the sandstones point to andesitic and felsic volcanic rock sources. The sandstones and mudstones have intermediate SiO 2/Al 2O 3 (typically 3-6), high Fe 2O 3 + MgO contents (5-12 wt%), and moderate to high K 2O/Na 2O ratios (generally 0.1-1 and 1-10 for sandstones and mudstones, respectively). In comparison with average upper continental crust, they show strong negative Nb-Ta anomalies, slight depletion of Zr-Hf, La and Th, but moderate enrichment of V, Cr, Ni, and Sc. These rocks show LREE enrichment (La/Yb N = 5.3-7.4) with flat HREE, and pronounced negative Eu anomalies (Eu/Eu * = 0.6-0.74) in chondrite-normalized REE patterns, similar to post-Archean shales. Geochemical data for these rocks suggest an arc setting and intermediate-felsic volcanic source, consistent with a back-arc basin scenario for the basaltic lavas in the lower Yanbian Group. Together with regional geological evidence, the turbidites of the Yanbian Group strongly support a model in which the western margin of the Yangtze Block was a major magmatic arc, active probably from ∼920 Ma to 740 Ma, a period of more than 180 million years. © 2008 Elsevier B.V. All rights reserved.postprin

Balanced geological section for extensional tectonic basin and its implication: An example from southern Songliao Basin

挤压构造的平衡地质剖面分析已经广泛应用于造山带构造分析, 但伸展构造区的平衡地质剖面分析实例仍然很少. 运用盆地分析的技术与方法, 分层序或阶段将地质构造依次恢复、地层逐层回剥, 并通过在松辽盆地南部吉林两井油田扶余油层4 条剖面的实践, 复原出不同时代盆地构造与地层发育的连续剖面, 揭示出松辽盆地南部主要构造样式是以浅表构造层次的负花状构造及深层剥离断层发育为特征; 断层生长指数、盆地的伸展史和伸展量等参数显示, 晚白垩世是构造转型的重要阶段, 此前主要为走滑构造样式形成阶段, 此后则主要为伸展滑脱构造发育阶段. 在此基础上, 提出松辽盆地具有伸展- 走滑双重力学构造性质, 可能是一个弧后构造盆地.The balanced geological sect ion has been widely used for the analysis of orogenic belt, but it is infrequent for ex tensional basins. In this paper, 4 extensional balanced geological sect ion analysis were practiced in Fuyu oil layer of Liangjing , Jilin oilfield, southern Songliao basin with the technology and method, including deformation history restoration, decompaction and erosion restoration. The structure of different ages and the continuous sedimentary sections have been restored. T he result s show that the structural styles possess the characteristics of negative flower structure in the shallow level and ex tensional detachment in deep level. The parameters, including fault growth index, the basin ex tensional history and fault detachment depth, indicate that Late Cretaceous is an important stage for the structure transferring mainly with a strike-slip style before this time and an ex tensional structure and detachment after this time. Therefore, a basin model with twin dynamic property and back-arc characters is proposed.published_or_final_versio

Heterogeneous mantle source and magma differentiation of quaternary arc-like volcanic rocks from Tengchong, SE margin of the Tibetan Plateau

The Tengchong volcanic field north of the Burma arc comprises numerous Quaternary volcanoes in the southeastern margin of the Tibetan Plateau. The volcanic rocks are grouped into four units (1-4) from the oldest to youngest. Units 1, 3 and 4 are composed of olivine trachybasalt, basaltic trachyandesite and trachyandesite, and Unit 2 consists of hornblende dacite. The rocks of Units 1, 3, and 4 form a generally alkaline suite in which the rocks plot along generally linear trends on Harker diagrams with only slight offset from unit to unit. They contain olivine phenocrysts with Fo values ranging from 65 to 85 mol% and have Cr-spinel with Cr# ranging from 23 to 35. All the rocks have chondrite-normalized REE patterns enriched in LREE and primitive mantle-normalized trace element patterns depleted in Ti, Nb and Ta, but they are rich in Th, Ti and P relative to typical arc volcanics. Despite minor crustal contamination, 87Sr/ 86Sr ratios (0.706-0.709), εNd values (-3.2 to -8.7), and εHf values (+4.8 to -6.4) indicate a highly heterogeneous mantle source. The Pb isotopic ratios of the lavas ( 206Pb/ 204Pb = 18.02-18.30) clearly show an EMI-type mantle source. The underlying mantle source was previously modified by subduction of the Neo-Tethyan oceanic and Indian continental lithosphere. The present heterogeneous mantle source is interpreted to have formed by variable additions of fluids and sediments derived from the subducted Indian Oceanic lithosphere, probably the Ninety East Ridge. Magma generation and emplacement was facilitated by transtensional NS-trending strike-slip faulting. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 28 May 201

SHRIMP zircon geochronology of the Emeishan Large Igneous Province (SW China): implications for double mass extinctions in Late Permian

Abstract in http://www.lpi.usra.edu/meetings/gold2001/pdf/3519.pd

Children and older adults exhibit distinct sub-optimal cost-benefit functions when preparing to move their eyes and hands

"© 2015 Gonzalez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited"Numerous activities require an individual to respond quickly to the correct stimulus. The provision of advance information allows response priming but heightened responses can cause errors (responding too early or reacting to the wrong stimulus). Thus, a balance is required between the online cognitive mechanisms (inhibitory and anticipatory) used to prepare and execute a motor response at the appropriate time. We investigated the use of advance information in 71 participants across four different age groups: (i) children, (ii) young adults, (iii) middle-aged adults, and (iv) older adults. We implemented 'cued' and 'non-cued' conditions to assess age-related changes in saccadic and touch responses to targets in three movement conditions: (a) Eyes only; (b) Hands only; (c) Eyes and Hand. Children made less saccade errors compared to young adults, but they also exhibited longer response times in cued versus non-cued conditions. In contrast, older adults showed faster responses in cued conditions but exhibited more errors. The results indicate that young adults (18 -25 years) achieve an optimal balance between anticipation and execution. In contrast, children show benefits (few errors) and costs (slow responses) of good inhibition when preparing a motor response based on advance information; whilst older adults show the benefits and costs associated with a prospective response strategy (i.e., good anticipation)

Theoretical and experimental studies of the bell-jar-top inductively coupled plasma

The present paper describes a systematic study of argon plasmas in a bell-jar inductively coupled plasma (ICP) source over the range of pressure 5-20 mtorr and power input 0.2-0.5 kW, Experimental measurements as well as results of numerical simulations are presented. The models used in the study include the well-known global balance model (or the global model) as well as a detailed two-dimensional (2-D) fluid model of the system, The global model is able to provide reasonably accurate values for the global electron temperature and plasma density, The 2-D model provides spatial distributions of various plasma parameters that make it possible to compare with data measured in the experiments, The experimental measurements were obtained using a tuned Langmuir double-probe technique to reduce the RF interference and obtain the light versus current (I-V) characteristics of the probe. Time-averaged electron temperature and plasma density were measured for various combinations of pressure and applied RF power, The predictions of the 2-D model were found to be in good qualitative agreement with measured data, It was found that the electron temperature distribution T-e was more or less uniform in the chamber, It was also seen that the electron temperature depends primarily on pressure, but is almost independent of the power input, except in the very low-pressure regime. The plasma density goes up almost linearly with the power input

Association of Clinical Factors and Therapeutic Strategies With Improvements in Survival Following Non-ST-Elevation Myocardial Infarction, 2003-2013.

Importance: International studies report a decline in mortality following non–ST-elevation myocardial infarction (NSTEMI). Whether this is due to lower baseline risk or increased utilization of guideline-indicated treatments is unknown. Objective: To determine whether changes in characteristics of patients with NSTEMI are associated with improvements in outcomes. Design, Setting, and Participants: Data on patients with NSTEMI in 247 hospitals in England and Wales were obtained from the Myocardial Ischaemia National Audit Project between January 1, 2003, and June 30, 2013 (final follow-up, December 31, 2013). Exposures: Baseline demographics, clinical risk (GRACE risk score), and pharmacological and invasive coronary treatments. Main Outcomes and Measures: Adjusted all-cause 180-day postdischarge mortality time trends estimated using flexible parametric survival modeling. Results: Among 389 057 patients with NSTEMI (median age, 72.7 years [IQR, 61.7-81.2 years]; 63.1% men), there were 113 586 deaths (29.2%). From 2003-2004 to 2012-2013, proportions with intermediate to high GRACE risk decreased (87.2% vs 82.0%); proportions with lowest risk increased (4.2% vs 7.6%; P= .01 for trend). The prevalence of diabetes, hypertension, cerebrovascular disease, chronic obstructive pulmonary disease, chronic renal failure, previous invasive coronary strategy, and current or ex-smoking status increased (all P < .001). Unadjusted all-cause mortality rates at 180 days decreased from 10.8% to 7.6% (unadjusted hazard ratio [HR], 0.968 [95% CI, 0.966-0.971]; difference in absolute mortality rate per 100 patients [AMR/100], −1.81 [95% CI, −1.95 to −1.67]). These findings were not substantially changed when adjusted additively by baseline GRACE risk score (HR, 0.975 [95% CI, 0.972-0.977]; AMR/100, −0.18 [95% CI, −0.21 to −0.16]), sex and socioeconomic status (HR, 0.975 [95% CI, 0.973-0.978]; difference in AMR/100, −0.24 [95% CI, −0.27 to −0.21]), comorbidities (HR, 0.973 [95% CI, 0.970-0.976]; difference in AMR/100, −0.44 [95% CI, −0.49 to −0.39]), and pharmacological therapies (HR, 0.972 [95% CI, 0.964-0.980]; difference in AMR/100, −0.53 [95% CI, −0.70 to −0.36]). However, the direction of association was reversed after further adjustment for use of an invasive coronary strategy (HR, 1.02 [95% CI, 1.01-1.03]; difference in AMR/100, 0.59 [95% CI, 0.33-0.86]), which was associated with a relative decrease in mortality of 46.1% (95% CI, 38.9%-52.0%). Conclusions and Relevance: Among patients hospitalized with NSTEMI in England and Wales, improvements in all-cause mortality were observed between 2003 and 2013. This was significantly associated with use of an invasive coronary strategy and not entirely related to a decline in baseline clinical risk or increased use of pharmacological therapies

Evaluation of the impact of the GRACE risk score on the management and outcome of patients hospitalised with non-ST elevation acute coronary syndrome in the UK: protocol of the UKGRIS cluster-randomised registry-based trial

Introduction For non-ST-segment elevation acute coronary syndrome (NSTEACS) there is a gap between the use of class 1 guideline recommended therapies and clinical practice. The GRACE risk score is recommended in international guidelines for the risk stratification of NSTEACS, but its impact on adherence to guideline-indicated treatments and reducing adverse clinical outcomes is unknown. The objective of the UKGRIS trial is to assess the effectiveness of the GRACE risk score tool and associated treatment recommendations on the use of guideline-indicated care and clinical outcomes. Methods and Analysis The UK GRACE Risk Score Intervention Study (UKGRIS), a parallel-group cluster randomised registry-based controlled trial, will allocate hospitals in a 1:1 ratio to manage NSTEACS by standard care or according to the GRACE risk score and associated international guidelines. UKGRIS will recruit a minimum of 3000 patients from at least 30 English National Health Service hospitals and collect healthcare data from national electronic health records. The co-primary endpoints are the use of guideline-indicated therapies, and the composite of cardiovascular death, non-fatal myocardial infarction, new onset heart failure hospitalisation or cardiovascular readmission at 12 months. Secondary endpoints include duration of inpatient hospital stay over 12 months, EQ-5D-5L responses and utilities, unscheduled revascularisation and the components of the composite endpoint over 12 months follow-up. Ethics and Dissemination The study has ethical approval (North East - Tyne & Wear South Research Ethics Committee ref: 4/NE/1180). Findings will be announced at relevant conferences and published in peer-reviewed journals in line with the funder’s open access policy. Registration ISRCTN29731761, registered 12th January 2017