Deep geothermal resource assessment of early carboniferous limestones for Central and Southern Great Britain

Early Carboniferous limestones (ECL) host active geothermal systems in Central and Southern Britain. Equivalent rocks have been successfully developed for geothermal energy in Belgium and the Netherlands, but the ECL has yet to be fully assessed as a geothermal resource in Britain. We use established statistical methods to assess the depth, distribution, and geothermal potential of the ECL in Central and Southern Britain. Total heat in place (HIP) resources of 1415 (P10)–1528 (P90) EJ may be present, with a tentative potential recoverable thermal power of 106–222 GW. Further work is needed to understand the resource by identifying areas with sufficient flow rates for successful development such as enhanced permeability zones around faults, fractures or karsts

The Geology and Geophysics of the United Arab Emirates. Volume 6, Geology of the western and central United Arab Emirates

This volume forms part of the product of a multidisciplinary study by the British Geological Survey (BGS), commissioned by the UAE Federal Government, Ministry of Energy, to produce 1:100 000 scale geological maps of the bedrock and superficial geology of the central and western part of the UAE. 1:50 000 scale maps were produced of selected areas near Abu Dhabi and for seven emergent salt domes (mainly on offshore islands). This document therefore follows on from the previous volume (Styles et al., 2006) on the geology of the northern Emirates. The present volume similarly contains information about the findings of the geological mapping and associated specialist research. Much of the central and western part of the UAE is blanketed by Quaternary and recent dune sands, fluvial sediments and sabkhas. The only significant areas of exposed older rocks occur along the coast between Abu Dhabi and As Sila and on the various salt islands. Previous geological maps were made more than 20 years ago and were based largely on air photo interpretation with limited ground-truthing. The rapid economic development in the intervening period has seen a tremendous expansion of the national infrastructure and this has greatly increased the demand for high quality, field-based geological maps. The area was mapped at a scale of 1:50 000 and maps produced at 1:100 000, with the exception of the salt dome islands which were mapped at 1:25 000 scale. An area of the coast around Abu Dhabi is illustrated in two additional maps produced at 1:50 000 scale. Each 1:100 000 scale map is accompanied by a Sheet Explanation that describes the rock sequences in the area covered by that particular map. This report describes the broader features of the main rock groups on a regional basis and includes the results of the specialist laboratory studies that were used to define and interpret the geology of the project area. The field mapping was undertaken in the winter months between October 2008 and March 2011. The mapping was carried out by A R Farrant, R A Ellison, R J Thomas, J W Merritt, S J Price, A J Newell, J Merritt, J R Lee, A B Leslie, H F Burke, R A Smith, K M Goodenough, A Finlayson, C J Jordan and S L B Arkley. The laboratory studies were mostly carried out at the BGS. The petrographic study of the Miocene and Quaternary rocks and sediments was carried out by E R Phillips, whilst the igneous petrology of the Hormuz Complex rocks was undertaken by members of the mapping team. I P Wilkinson undertook micropalaeontologial determinations of both Miocene and recent sediments. The macropalaeontology of the basal Baynunah Formation is based largely on published information provided by Dr Mark Beech, Professor Andrew Hill and Dr Faisal Bibi. Some additional data on the Fars Group was provided by M A Woods. R Knox did the heavy mineral analyses, whilst D Wagner and S Kemp worked on the XRD analysis. The U-Pb zircon and carbonate geochronology was undertaken by M Horstwood, N Roberts and R Parrish at the NERC Isotope Geoscience Laboratories at the BGS, Keyworth. The Optically Stimulated Luminescence (OSL) dating was carried out by Professor G Duller and Dr H Roberts in the Aberystwyth Luminescence Research Laboratory at the Institute of Geography and Earth Sciences, Aberystwyth University. P Turner and C Simpson were responsible for the GIS systems and map layouts. H Holbrook and S Ward drew the majority of the illustrations. W Masterson and A Hill formatted this Memoir and the Sheet Explanations. This volume was compiled by A R Farrant and edited by R J Thomas

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Survival ratio plots with permutation envelopes in survival data problems

A new method is proposed, based on a simple ratio plot, which is useful for identifying time intervals or regions in which survival prospects differ between two distinct populations or treatments. In order to investigate whether any observed difference or trend is due to sampling variation or is due to a possible real effect, resampling techniques are used to generate permutation envelopes as reference bands. The method is applicable to the comparison of survival in two populations for both independent and paired survival problems and also to the assessment of the symmetry of a bivariate survival function