Yorkshire geology as seen through the eyes of notable British Geological Survey geologists 1862-2000

This paper was presented at the PLACE (People, Landscape & Cultural Environment Education and Research Centre) conference 3rd October 2015. It describes some of the major contributions made to the understanding of Yorkshire geology by geologists of the British Geological Survey from the early directors through to the end of the 20th Century. It briefly describes the founding work of William Smith in Yorkshire and the early years of the Geological Survey under Sir Henry De La Beche then Sir Roderick Impey Murchison. The outstanding work of Murchison's Yorkshire "boys" is noted including details of the contributions made by A H Green, J R Dakyns, R H Tiddeman, J C Ward, C E Fox-Strangways and G. Barrow. These outstanding geologists laid the foundations for our understanding of the Yorkshire coalfield, the Pennine sedimentary blocks and basins, the structures and hydrogeology of the Carboniferous rocks, the Yorkshire Jurassic and glacial deposits. The years of the 2nd World War are noted with the work of R L Sherlock, G H Mitchell and Sir Kingsley Dunham all of whom contributed to the Nation’s need for minerals to supply the war effort. Finally, the work of D B Smith is described showing how he unravelled the complexities of the Permian sequence of Yorkshire

Road and bridge construction across gypsum karst in England

Gypsum karst problems in the Permian and Triassic sequences of England have caused difficult conditions for bridge and road construction. In Northern England, the Ripon Bypass crosses Permian strata affected by active gypsum karst and severe subsidence problems. Here, the initial borehole site investigation for the road was supplemented by resistivity tomography studies. The roadway was reinforced with two layers of tensile membrane material within the earth embankment. This will prevent dangerous catastrophic collapse, but will allow sagging to show where problems exist. The River Ure Bridge was constructed across an area of subsidence pipes filled with alluvial deposits. It was built with extra strength, larger than normal foundations. If one pier fails, the bridge is designed for adjacent arches to span the gap without collapse. The bridge piers are also fitted with electronic load monitoring to warn of failure. In the Midlands area of England, road construction over Triassic gypsum has required a phase of ground improvement on the Derby Southern Bypass. Here, the gypsum caps a hill where it was formerly mined; it dips through a karstic dissolution zone into an area of complete dissolution and collapse. The road and an associated flyover were built across these ground conditions. A major grouting program before the earthworks began treated the cavities in the mine workings and the cavernous margin of the gypsum mass. Within the karstic dissolution zone, gypsum blocks and cavities along the route were identified by conductivity and resistivity geophysical surveys, excavated and backfilled. In the areas of complete dissolution and collapse, the road foundation was strengthened with vibrated stone columns and a reinforced concrete road deck was used

Road construction over voids caused by active gypsum dissolution, with an example from Ripon, North Yorkshire, England

Sudden subsidence problems, caused by gypsum karst developed in the Permian sequence of Northern England, have caused difficult conditions for road construction. This paper presents the design strategy, mathematical modelling and parameters used to construct roads to cope with such difficult ground conditions. Because it is impossible to locate all the subsidence features along a route, the road design has to cope with potential future problems. This is achieved by using reinforcementcomprising layers of tensile membrane material within the earth embankment. This will prevent dangerous catastrophic collapse and maintain serviceability, but will allow sagging to show where major problems exist. The modelling showed that for the situation at Ripon, two layers of tensile membrane material within the earth embankment fulfilled the design brief for the road

Planning for gypsum geohazards in Lithuania and England

The rapid underground dissolution of gypsum, and the evolution of the gypsum karst in Lithuania and England, results in subsidence problems which can make construction difficult. The natural dissolution yields sulphate-rich groundwater of poor quality and the karst is susceptible to the rapid transmission of pollutants. In the north of Lithuania gypsum karst is developed in Devonian gypsum. Here the towns of Birai, Pasvalys and the surrounding countryside suffer subsidence and some buildings have been damaged. The majority of the potable water in these areas is derived from groundwater extracted from sandstone sequences that underlie the gypsum. In Lithuania conservation measures have been introduced to control agriculture and prevent pollution of the gypsum karst. These measures include environmentally-friendly farming, restrictions on land use and exclusion zones around subsidence hollows. In England subsidence caused by the dissolution of Permian gypsum has caused severe problems in the vicinity of the town of Ripon. Numerous buildings have been damaged and new sites are difficult to develop. Here formal planning regulations have recently been introduced to help to protect against the worst effects of subsidence resulting from gypsum dissolution

The stratigraphy and palaeontology of the Ordovician to Devonian rocks of the area north of Dornes (near Figueiródos Vinhos), central Portugal.

The Ordovician, Silurian and lower Devonian rocks of the Domes area (near Figueiro dos Vinhos), in central Portugal, form a continuous sedimentary sequence approximately 1450m thick. Folded Pre-Ordovician "Complexo xisto-grauvaquico" (CXG) is unconformably overlain by a transgressive quartzite, mudstone and greywacke succession of four Ordovician formations which are locally shelly and graptolitic. These formations are: Serra do Brejo Formation, Brejo Fundeiro Formation, Monte da Sombadeira Formation and Monte do Carvalhal Formation. The Ordovician rocks are conformably overlain by a Silurian sequence of graptolitic mudstones passing upwards into sandstones; these beds include the Vale da Ursa Formation, Foz da Serta Formation, Vale do Serräo Formation, Serra da Mendeira Formation and part of the Serra do Luacäo Formation. The Devonian rocks are represented by part of the Serra do Luagao Formation and the Dornes formation, a sandstone-madstone sequence passing up into Shelly limestones. Most of the Ordovician faunas are described and discussed including sixteen species of trilobite, five species of brachiopod and eleven ichnospecies of trace fossil. Faunal lists of material identified by specialists in the fields of Ordovician and Silurian graptolites, Ordovician echinoderms, Devonian brachiopods and Silurian microfossils are also given. The Ordovician faunas belong to the Selenopeltis province and show close links with those of Spain, France, Morocco and Bohemia. The correlation and palaeogeography of the Dornes area is discussed with emphasis on the Ordovician Period in the Ibero-Armorican area

Comment on Fano Line Shapes Reconsidered: Symmetric Photoionization Peaks from Pure Continuum Excitation

A Comment on the Letter by U. Eichmann. T. F. Gallagher, and R. M. Konik, Phys. Rev. Lett. 90, 233004 (2003). The authors of the Letter offer a Reply

Evidence for a stratigraphic basis for the Anthropocene

The Anthropocene was proposed as a term (Crutzen and Stoermer 2000) before consideration was given to the nature of the key signatures, contrasting with standard procedures for defining such units. The term is being widely used in both popular and scientific publications before a decision is made as to whether it warrants formalisation and definition of a Global Stratigraphic Section and Point (GSSP). The deliberate human modification of the landscape and its subsurface, and the creation of human-generated novel sedimentary deposits, minerals, and landforms, are characteristic features of the development of Earth’s surface and near surface, which has accelerated in the past two centuries. The large-scale intentional excavation, transportation, and deposition of mixtures of rock and soil to form anthropogenic deposits and landforms represent a new geological process that could be used as a diagnostic signature of the Anthropocene

Multi-reflection polarimetry in microfluidics

The field of microfluidics promises new portable, low-cost sensing systems, as well as the capabilities to measure the physical or chemical properties of precious samples, for which only small volumes are available. However, when using microfluidic channels with millimeter to micron scale dimensions, together with optical sensing methods, these configurations result in short path lengths over which the signal can be acquired. Whilst polarimetry would greatly benefit from using small volumes, providing important information on the structure of chiral biomarkers in life sciences, the small interrogation volumes associated with the use of minute samples decreases the numbers of molecules in the light path that cause an optical rotation and reduces the sensitivity of the technique. Here, we show that when an optical beam, passing through a chiral sample, undergoes multiple reflections from suitably aligned external micromirrors, the usual cancelling out of the optical rotation, that occurs when the rotated polarized beam is passed back through a solution following reflection at a single mirror, can be negated. This enables the chirality of molecular species present in a microfluidic sample to be measured with increased sensitivity. This approach was validated experimentally using solutions of D-(+)-glucose as a model system, by investigating the effect of multiple reflections of a linearly polarized He-Ne laser beam and a 403 nm diode laser beam across the microfluidic channel. It was found that there was a 30-fold enhancement in the limit of detection with as few as 11 reflections through the sample

Effects of Verapamil SR and Atenolol on 24-Hour Blood Pressure and Heart Rate in Hypertension Patients with Coronary Artery Disease...

Elevated night-time blood pressure (BP) and heart rate (HR), increased BP and HR variability, and altered diurnal variations of BP and HR (nighttime dipping and morning surge) in patients with systemic hypertension are each associated with increased adverse cardiovascular events. However, there are no reports on the effect of hypertension treatment on these important hemodynamic parameters in the growing population of hypertensive patients with atherosclerotic coronary artery disease (CAD). This was a pre-specified subgroup analysis of the INternational VErapamil SR-Trandolapril STudy (INVEST), which involved 22,576 clinically stable patients aged ≥50 years with hypertension and CAD randomized to either verapamil SR- or atenolol-based hypertension treatment strategies. The subgroup consisted of 117 patients undergoing 24-hour ambulatory monitoring at baseline and after 1 year of treatment. Hourly systolic and diastolic BP (SBP and DBP) decreased after 1 year for both verapamil SR- and atenolol-based treatment strategies compared with baseline (P<0.0001). Atenolol also decreased hourly HR (P<0.0001). Both treatment strategies decreased SBP variability (weighted standard deviation: P = 0.012 and 0.021, respectively). Compared with verapamil SR, atenolol also increased the prevalence of BP and HR night-time dipping among prior non-dippers (BP: OR = 3.37; 95% CI: 1.26 – 8.97; P = 0.015; HR: OR = 4.06; 95% CI: 1.35-12.17;P = 0.012) and blunted HR morning surge (+2.8 vs. +4.5 beats/min/hr; P = 0.019). Both verapamil SR- and especially atenolol-based strategies resulted in favorable changes in ambulatory monitoring parameters that have been previously associated with increased adverse cardiovascular events