Geology and tectonic evolution of the Western Approaches Trough

Maps/charts relating to this thesis have not been filmed, please apply direct to the issuing universityAvailable from British Library Document Supply Centre- DSC:D77549 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

Contemporary stress orientations in the Faroe-Shetland region

The Faroe-Shetland Region (FSR) of the NE Atlantic continental margin contains a number of complexly structured Mesozoic-Palaeogene-age rift basins, but in comparison to the contiguous British Isles and North Sea Basin, the state of crustal stress in the FSR is poorly understood. The orientation of maximum horizontal compressional stress (σHmax) across most of NW Europe is ~NW-SE, which is considered to be controlled by forces acting at the plate boundaries. We have determined 16 B-D quality σHmax orientations based on borehole breakouts interpreted in petroleum wells, and define three distinct stress provinces within the FSR. Stress orientations in the NE are ~NW-SE, consistent with the regional pattern of stresses in NW Europe and local neotectonic structural trends. However, contemporary stress orientations in the central and SW of the FSR exhibit short-wavelength (distances <10-50 km) variation, with NE-SW, N-S and E-W orientations that are parallel or sub-parallel to underlying structural trends. This variation is interpreted in terms of stress deflections towards weak faults that downthrow the Mesozoic-Cenozoic sedimentary successions against basement highs. These local-scale sources are superposed on a background ~WNW-ESE σHmax orientation that is controlled by both plate boundary forces and regional-scale sources of stresses

Determining apparent exhumation from Chalk outcrop samples, Cleveland Basin/East Midlands Shelf.

Porosity measurements of 22 Upper Cretaceous Chalk samples, and mean Chalk porosities derived from sonic logs in three wells, were used to quantify apparent exhumation (height above maximum burial-depth) in the onshore Cleveland Basin/East Midlands Shelf. Late Cretaceous/Tertiary exhumation of the East Midlands Shelf resulted in the removal of 1.2 km of section near the coast and more than 2 km of section inland, to the west. The southern margin of the Cleveland Basin was exhumed by 2 km, and exhumation increases northwards towards the recognized inversion axis running east–west along the basin’s centre. The northwards increasing exhumation associated with the east–west trending inversion axis of the Cleveland Basin is superimposed upon the regional westward trend of increasing exhumation of eastern England. These two trends control the outcrop distribution of the Upper Cretaceous Chalk in the Cleveland Basin/East Midlands Shelf.Robert J. Menpes and Richard R. Hilli

Present-day stress orientations and tectonic provinces of the NW Borneo collisional margin

Extent: 15p.Borehole failure observed on image and dipmeter logs from 55 petroleum wells across the NW Borneo collisional margin were used to determine maximum horizontal stress (σH) orientations; combined with seismic and outcrop data, they define seven tectonic provinces. The Baram Delta–Deepwater Fold-Thrust Belt exhibits three tectonic provinces: its inner shelf inverted province (σH is NW-SE, margin-normal), its outer shelf extension province (σH is NE-SW, margin-parallel), and its slope to basin floor compression province (σH is NW-SE, margin-normal). In the inverted province, σH reflects inversion of deltaic normal faults. The σH orientations in the extension and compression provinces reflect deltaic gravitational tectonics. The shale and minibasin provinces have been recognized in offshore Sabah. In the shale province, σH is N010°E, which aligns around the boundary of a massif of mobile shale. Currently, no data are available to determine σH in the minibasin province. In the Balingian province, σH is ESE-WNW, reflecting ESE absolute Sunda plate motions due to the absence of a thick detachment seen elsewhere in NW Borneo. The Central Luconia province demonstrates poorly constrained and variable σH orientations. These seven provinces result from the heterogeneous structural and stratigraphic development of the NW Borneo margin and formed due to complex collisional tectonics and the varied distribution and thicknesses of stratigraphic packages.Rosalind C. King, Mark R. P. Tingay, Richard R. Hillis, Christopher K. Morley, and James Clar

The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2002

Called for by the U.S. Coral Reef Task Force’s (USCRTF) National Action Plan to Conserve Coral Reefs, this is the first biennial report on the condition of coral reefs. It is the scientific baseline for subsequent reports on the health of U.S. coral reef ecosystems that are to be used by NOAA and others to evaluate the efficacy of coral reef conservation and management practices. The National Oceanic and Atmospheric Administration’s National Ocean Service led the development of this report. It was authored by 38 experts and supported by 79 contributors from government agencies and non-governmental organizations across the nation and internationally. Over 100 Task Force members and other notable scientists have reviewed this document

Design mining interacting wind turbines

© 2016 by the Massachusetts Institute of Technology. An initial study has recently been presented of surrogate-assisted evolutionary algorithms used to design vertical-axis wind turbines wherein candidate prototypes are evaluated under fan-generated wind conditions after being physically instantiated by a 3D printer. Unlike other approaches, such as computational fluid dynamics simulations, no mathematical formulations were used and no model assumptions weremade. This paper extends that work by exploring alternative surrogate modelling and evolutionary techniques. The accuracy of various modelling algorithms used to estimate the fitness of evaluated individuals from the initial experiments is compared. The effect of temporally windowing surrogate model training samples is explored. A surrogateassisted approach based on an enhanced local search is introduced; and alternative coevolution collaboration schemes are examined

Thermal weakening localizes intraplate deformation along the southern Australian continental margin

The controls on seismicity and fault reactivation in stable intraplate crust located far from active plate boundaries are poorly understood. The southern Australian continental margin has been undergoing mild levels of deformation over the past ~10 Myr, manifested today by high levels of seismicity for a stable intraplate region. However, this deformation is partitioned, with zones of abundant neotectonic faults with evidence for Pliocene–Quaternary displacement, enhanced relief (up to 1–2 km) and high seismicity (numerous M > 5 earthquakes) such as the Flinders Ranges adjoining areas of little neotectonic activity, subdued topography and low levels of seismicity such as the Murray Basin and Nullarbor Plain. Here we present a new compilation of 192 heat flow data for the southern Australian margin. Variations in heat flow correlate well with variations in neotectonic and seismic activity, with regions of deformation corresponding to elevated heat flows of up to ~90 mW m− 2. We propose that the southern Australian margin provides the best evidence to-date that active intraplate deformation may be localized and controlled by the thermal properties of the crust and upper mantle.Simon P. Holford, Richard R. Hillis, Martin Hand, Mike Sandifor

Inferring Phylogenies from RAD Sequence Data

Reduced-representation genome sequencing represents a new source of data for systematics, and its potential utility in interspecific phylogeny reconstruction has not yet been explored. One approach that seems especially promising is the use of inexpensive short-read technologies (e.g., Illumina, SOLiD) to sequence restriction-site associated DNA (RAD) – the regions of the genome that flank the recognition sites of restriction enzymes. In this study, we simulated the collection of RAD sequences from sequenced genomes of different taxa (Drosophila, mammals, and yeasts) and developed a proof-of-concept workflow to test whether informative data could be extracted and used to accurately reconstruct “known” phylogenies of species within each group. The workflow consists of three basic steps: first, sequences are clustered by similarity to estimate orthology; second, clusters are filtered by taxonomic coverage; and third, they are aligned and concatenated for “total evidence” phylogenetic analysis. We evaluated the performance of clustering and filtering parameters by comparing the resulting topologies with well-supported reference trees and we were able to identify conditions under which the reference tree was inferred with high support. For Drosophila, whole genome alignments allowed us to directly evaluate which parameters most consistently recovered orthologous sequences. For the parameter ranges explored, we recovered the best results at the low ends of sequence similarity and taxonomic representation of loci; these generated the largest supermatrices with the highest proportion of missing data. Applications of the method to mammals and yeasts were less successful, which we suggest may be due partly to their much deeper evolutionary divergence times compared to Drosophila (crown ages of approximately 100 and 300 versus 60 Mya, respectively). RAD sequences thus appear to hold promise for reconstructing phylogenetic relationships in younger clades in which sufficient numbers of orthologous restriction sites are retained across species