The Great Glen Caledonian Igneous Suite: new geochemical and geochronological insights into the final stages of the Caledonian Orogeny

The Caledonian Orogeny is responsible for the consolidation of British and Irish crust and the intrusion of an extensive suite of granite (sensu – lato) plutons and dykes. Said intrusions are collectively known as the Newer granites and are a natural laboratory for studying mid-crustal petrogenetic processes in a post- collisional setting. Recent workers have highlighted inconsistencies in the timeline of events for the final stages of the orogeny (the so-called ‘Scandian phase’), particularly regarding the timing and geodynamic processes associated with Newer granite magmatism. New single grain U – Pb zircon data from three undated Newer granite bodies (Glen Loy, Cluanie and Loch Linnhe), and whole rock geochemical data from five (Glen Loy, Cluanie, Loch Linnhe Clunes and Scaddle) will facilitate new insights into said issues. Intrusions at Glen Loy, Cluanie and Loch Linnhe return ages of 433.6 +/- 3.9, 437.7 +/- 3.3 and 439.4 +/-3.1 respectively (+/- 2σ). Their emplacement therefore predates estimates for slab break–off, usually invoked as the mechanism behind Newer granite melt generation, which requires some explanation. The geochemical profiles for Scaddle and Loy strongly suggest a mantle source, which requires explanation given their emplacement coincides with what is traditionally accepted as peak crustal thickening - another contradictory set of circumstances. As detailed, the newly acquired data is largely inconsistent with previously accepted geodynamic timelines for so called ‘Scandian’ events and supports a growing array of data suggesting the demarking of Caledonian orogenic events has been erroneous. A new model is presented, which includes Baltica - Laurentia collision occurring far earlier than traditional estimates of c. 430 Ma; instead occurring at c. 450 Ma. All subsequent events and processes are associated with crustal thickening, slab rollback, and eventual slab break-off

A comparison of penetration and damage caused by different types of arrowheads on loose and tight fit clothing

Bows and arrows are used more for recreation, sport and hunting in the Western world and tend not to be as popular a weapon as firearms or knives. Yet there are still injuries and fatalities caused by these low-velocity weapons due to their availability to the public and that a licence is not required to own them. This study aimed to highlight the penetration capabilities of aluminium arrows into soft tissue and bones in the presence of clothing. Further from that, how the type and fit of clothing as well as arrowhead type contribute to penetration capacity. In this study ballistic gelatine blocks (non-clothed and loose fit or tight fit clothed) were shot using a 24 lb weight draw recurve bow and aluminium arrows accompanied by four different arrowheads (bullet, judo, blunt and broadhead).The penetration capability of aluminium arrows was examined, and the depth of penetration was found to be dependent on the type of arrowhead used as well as by the type and fit or lack thereof of the clothing covering the block. Loose fit clothing reduced penetration with half of the samples, reducing penetration capacity by percentages between 0% and 98.33%, at a range of 10 m. While the remaining half of the samples covered with tight clothing led to reductions in penetration of between 14.06% and 94.12%.The damage to the clothing and the gelatine (puncturing, cutting and tearing) was affected by the shape of the arrowhead, with the least damaged caused by the blunt arrowheads and the most by the broadhead arrows. Clothing fibres were also at times found within the projectile tract within the gelatine showing potential for subsequent infection of an individual with an arrow wound.Ribs, femur bones and spinal columns encased in some of the gelatine blocks all showed varying levels of damage, with the most and obvious damage being exhibited by the ribs and spinal column.The information gleaned from the damage to clothing, gelatine blocks and bones could potentially be useful for forensic investigators, for example, when a body has been discovered with no weapons or gunshot residue present

Caledonian hot zone magmatism in the “Newer Granites”: insight from the Cluanie and Clunes plutons, Northern Scottish Highlands

Scottish “Newer” Granites record the evolution of the Caledonides resulting from Iapetus subduction and slab breakoff during the Silurian-Devonian Scandian Orogeny, but relationships between geodynamics, petrogenesis and emplacement are incomplete. Laser ablation U-Pb results from magmatic zircons at the Cluanie Pluton (Northern Highlands) identify clusters of concordant Silurian data points. A cluster with a weighted mean 206Pb/238U age of 431.6 ± 1.3 Ma (2 confidence interval, n = 6) records emplacement whilst older points (clustered at 441.8 ± 2.3 Ma, n = 9) record deep crustal hot zone magmatism prior to ascent. The Cluanie Pluton, and its neighbour the ∼428 Ma Clunes tonalite, have adakite-like high Na, Sr/Y, La/Yb and low Mg, Ni and Cr characteristics, and lack mafic facies common in other “Newer Granites”. These geochemical signatures indicate the tapping of batches of homogenised, evolved magma from the deeper crust. The emplacement age of the Cluanie Pluton confirms volumetrically modest subduction-related magmatism occurred beneath the Northern Highlands before slab breakoff, probably as a result of crustal thickening during the ∼450 Ma Grampian 2 event. Extensive new in-situ geochemical-geochronological studies for this terrane may further substantiate the deep crustal hot zone model and the association between Caledonian magmatism and potentially metallogenesis. The term “Newer Granites” is outdated as it ignores the demonstrated relationships between magmatism, Scandian orogenesis and slab breakoff. Hence, “Caledonian intrusions” would be a more appropriate generic term to cover those bodies related to either Iapetus subduction or to slab breakoff

Pleistocene - Holocene volcanism at the Karkar geothermal prospect, Armenia

Pleistocene to Holocene volcanic centres north of the Bitlis-Zagros suture in Turkey, Iran, Armenia and Georgia represent both volcanic hazards and potential or actual geothermal energy resources. Such challenges and opportunities cannot be fully quantified without understanding these volcanoes’ petrogenesis, geochronology and magmatic, tectonic or other eruption triggers. We discuss the age and igneous geology of the Karkar monogenetic volcanic field in Syunik, SE Armenia. The ~30 km2 field is beside the location of Armenia’s only geothermal energy test drilling site. Eruptions of fissure-fed trachybasaltic andesite to trachyandesite occurred on a trans-tensional pull-apart segment of the Pambak-Sevan-Syunik Fault and have previously been interpreted to be of Holocene age. We conducted high-resolution duplicate 40Ar/39Ar dating of 7 groundmass separates, providing composite plateau or inverse isochron ages ranging from 6 ± 3 ka to 332 ± 9 ka (2). Each lava flow displays petrographic and geochemical patterns consistent with melting of subduction-modified lithospheric mantle and crystal fractionation involving ol, sp, opx and cpx, amp and plg. Some crystal-scale zoning was observed, implying recharge prior to eruption, and a preliminary estimate of cpx crystallisation pressures indicates storage in the mid- to upper crust, which may be of relevance for geothermal developments. These data indicate that volcanic activity in Syunik and elsewhere in Armenia overlapped with human occupation and that the presence of a substantive heat source for geothermal energy and a lava inundation hazard for local infrastructure should be further considered. Additional geophysical monitoring of the Pambak-Sevan-Syunik Fault is merited, along with detailed determination of the depths of magma storage both here and also at Porak volcano 40 km north of Karkar

Pleistocene - Holocene volcanism at the Karkar geothermal prospect, Armenia

Quaternary volcanic centres north of the Bitlis-Zagros suture in Turkey, Iran and the Caucasus represent both volcanic hazards and potential or actual geothermal energy resources. Such challenges and opportunities cannot be fully quantified without understanding these volcanoes' petrogenesis, geochronology and magmatic, tectonic or other eruption triggers. In this preliminary study, we discuss the age and geology of the Karkar monogenetic volcanic field in Syunik, SE Armenia. The ∼70 km2 field is close to Armenia's only geothermal energy test drilling site. Fissure-fed trachybasaltic andesite to trachyandesite lavas erupted on a trans-tensional segment of the Syunik branch of the Pambak-Sevan-Syunik Fault, where previous studies suggested a Holocene age for the youngest eruptions. Here, high-resolution duplicate 40Ar/39Ar dating of 7 groundmass separates provided inverse isochron ages ranging from 7.4 ± 3.6 ka and 7.9 ± 2.9 ka to 353 ± 20 ka (2σ). Each lava flow displays petrographic and whole rock geochemical patterns consistent with melting of subduction-modified lithospheric mantle and extensive evolution within the crust involving fractional crystallisation and mixing of magma batches. Data confirm that volcanic activity related to the Syunik Fault overlapped with Palaeolithic to Bronze Age human occupation and remains a minor lava inundation hazard. Further geochemical work will allow constraint of the depth and timescales of magma storage. Both Karkar and the area around Porak volcano, which lies 35 km N of Karkar on the Syunik Fault, might be considered for future geothermal energy developments

Caledonian hot zone magmatism in the “Newer Granites”: insight from the Cluanie and Clunes plutons, Northern Scottish Highlands

No abstract available

Prospective observational cohort study on grading the severity of postoperative complications in global surgery research

Background The Clavien–Dindo classification is perhaps the most widely used approach for reporting postoperative complications in clinical trials. This system classifies complication severity by the treatment provided. However, it is unclear whether the Clavien–Dindo system can be used internationally in studies across differing healthcare systems in high- (HICs) and low- and middle-income countries (LMICs). Methods This was a secondary analysis of the International Surgical Outcomes Study (ISOS), a prospective observational cohort study of elective surgery in adults. Data collection occurred over a 7-day period. Severity of complications was graded using Clavien–Dindo and the simpler ISOS grading (mild, moderate or severe, based on guided investigator judgement). Severity grading was compared using the intraclass correlation coefficient (ICC). Data are presented as frequencies and ICC values (with 95 per cent c.i.). The analysis was stratified by income status of the country, comparing HICs with LMICs. Results A total of 44 814 patients were recruited from 474 hospitals in 27 countries (19 HICs and 8 LMICs). Some 7508 patients (16·8 per cent) experienced at least one postoperative complication, equivalent to 11 664 complications in total. Using the ISOS classification, 5504 of 11 664 complications (47·2 per cent) were graded as mild, 4244 (36·4 per cent) as moderate and 1916 (16·4 per cent) as severe. Using Clavien–Dindo, 6781 of 11 664 complications (58·1 per cent) were graded as I or II, 1740 (14·9 per cent) as III, 2408 (20·6 per cent) as IV and 735 (6·3 per cent) as V. Agreement between classification systems was poor overall (ICC 0·41, 95 per cent c.i. 0·20 to 0·55), and in LMICs (ICC 0·23, 0·05 to 0·38) and HICs (ICC 0·46, 0·25 to 0·59). Conclusion Caution is recommended when using a treatment approach to grade complications in global surgery studies, as this may introduce bias unintentionally

The surgical safety checklist and patient outcomes after surgery: a prospective observational cohort study, systematic review and meta-analysis

© 2017 British Journal of Anaesthesia Background: The surgical safety checklist is widely used to improve the quality of perioperative care. However, clinicians continue to debate the clinical effectiveness of this tool. Methods: Prospective analysis of data from the International Surgical Outcomes Study (ISOS), an international observational study of elective in-patient surgery, accompanied by a systematic review and meta-analysis of published literature. The exposure was surgical safety checklist use. The primary outcome was in-hospital mortality and the secondary outcome was postoperative complications. In the ISOS cohort, a multivariable multi-level generalized linear model was used to test associations. To further contextualise these findings, we included the results from the ISOS cohort in a meta-analysis. Results are reported as odds ratios (OR) with 95% confidence intervals. Results: We included 44 814 patients from 497 hospitals in 27 countries in the ISOS analysis. There were 40 245 (89.8%) patients exposed to the checklist, whilst 7508 (16.8%) sustained ≥1 postoperative complications and 207 (0.5%) died before hospital discharge. Checklist exposure was associated with reduced mortality [odds ratio (OR) 0.49 (0.32–0.77); P\u3c0.01], but no difference in complication rates [OR 1.02 (0.88–1.19); P=0.75]. In a systematic review, we screened 3732 records and identified 11 eligible studies of 453 292 patients including the ISOS cohort. Checklist exposure was associated with both reduced postoperative mortality [OR 0.75 (0.62–0.92); P\u3c0.01; I2=87%] and reduced complication rates [OR 0.73 (0.61–0.88); P\u3c0.01; I2=89%). Conclusions: Patients exposed to a surgical safety checklist experience better postoperative outcomes, but this could simply reflect wider quality of care in hospitals where checklist use is routine

Critical care admission following elective surgery was not associated with survival benefit: prospective analysis of data from 27 countries

This was an investigator initiated study funded by Nestle Health Sciences through an unrestricted research grant, and by a National Institute for Health Research (UK) Professorship held by RP. The study was sponsored by Queen Mary University of London