Heavy mineral analysis by ICP-AES a tool to aid sediment provenancing

Correlation and provenancing of sediments/sedimentary rocks can be achieved by several techniques; a common approach is through the identification and quantification of heavy minerals using a petrological microscope. This can be time consuming, the analysis of heavy minerals by inductively coupled plasma atomic emission spectroscopy offers a faster alternative, by determining key elements associated with specific heavy minerals. Here we outline a method for determining heavy mineral species though ICP-AES using high temperature fusion with a lithium metaborate flux to ensure complete dissolution of resistate minerals. The method was tested in a provenance study of desert sands from the United Arab Emirates. The results are compared with those derived from traditional optical microscopy. These show good agreement for minerals with specific geochemical signatures, whilst the overall geochemistry of the heavy mineral concentrate was diagnostic of potential sediment sources. This geochemical approach is capable of processing large numbers of samples rapidly and is advocated as a screening technique. A combination of geochemical and mineralogical data produced by these techniques provides a powerful diagnostic tool for studies of heavy mineral signatures in sediments frequently used in mineral reconnaissance, paleogeographic reconstruction and reservoir characterisation in the petroleum industry

Speleogenetic evidence from Ogof Draenen for a pre-Devensian glaciation in the Brecon Beacons, South Wales, UK

The British Isles have been affected by as many as 30 glaciations during the Quaternary. However, the evidence for pre-Devensian glaciations in upland regions is scarce. Understanding the extent and timing of earlier upland glaciations is essential for modelling the long-term evolution and sensitivity of the British Ice Sheet. Caves, being protected from surface erosion and weathering, can preserve evidence of earlier glaciations in the form of speleothem and sediment archives. The ∼70-km-long Ogof Draenen cave system in South Wales, UK, contains multiple cave levels related to changes in the surface topography and drainage during the past 0.5 Ma. The cave contains evidence of massive influxes of sediment that were sufficient to choke the cave and alter the underground drainage. Analysis of the cave sediments, passage morphology and geometry suggests the cave once acted as a subterranean glacial spill-way before being overridden by ice. Speleothem U-series data demonstrate that this sediment influx occurred before Marine Isotope State (MIS) 9, probably during the Anglian glaciation (MIS 12). Evidence from Ogof Draenen indicates the impact of subsequent glaciations on the landscape evolution of the region was minimal and that much of the surface topography dates from the Anglian

Establishing and Prioritising Research Questions for the Treatment of Alopecia Areata: The Alopecia Areata Priority Setting Partnership

BACKGROUND: Alopecia areata is a common hair loss disorder that results in patchy to complete hair loss. Many uncertainties exist around the most effective treatments for this condition. OBJECTIVES: To identify uncertainties in alopecia areata management and treatment that are important to both service users (people with hair loss, carers and relatives) and healthcare professionals. METHODS: An alopecia areata priority setting partnership was established between patients, their carers and relatives, and healthcare professionals to identify the most important uncertainties in alopecia areata. The methodology of the James Lind Alliance was followed to ensure a balanced, inclusive and transparent process. RESULTS: In total 2747 treatment uncertainties were submitted by 912 participants, of which 1012 uncertainties relating to alopecia areata (and variants) were analyzed. Questions were combined into "indicative uncertainties" following a structured format. A series of ranking exercises further reduced this list to a top 25 that were taken to a final prioritization workshop where the top 10 priorities were agreed. CONCLUSIONS: We present the top 10 research priorities for alopecia areata to guide researchers and funding bodies to support studies important to both patients and clinicians. This article is protected by copyright. All rights reserved

Effects of seed storage and fire on germination in the nut-fruited Restionaceae species, Cannomois virgata

The effects of storage regime (laboratory and soil storage) and fire cues (heat and charate) on seed viability and germination were investigated in the nut-fruited Restionaceae species, Cannomois virgata (Rottb.) Steud. Soil-stored seeds were cycled through a series of alternating temperature and moisture regimes in a phytotron, while laboratory-stored seeds were kept at comparatively constant temperatures and low humidity. Seed deterioration in soil-stored seed was not significantly different to laboratory-stored seed. A marked improvement in germination of soil-stored seed was observed on exposure to charate from a fire