Making geological data accessible to non-geoscientists : a 3D model case history from Glasgow, U.K.

The British Geological Survey’s 3D geological framework modelling of the entire Glasgow conurbation and surrounding River Clyde catchment, has been undertaken as part of the Clyde-Urban Super-Project (CUSP) and in partnership with Glasgow City Council and other local and regulatory authorities. The 3D modelling covers an area of complex glacial superficial deposits, overlain by heterogeneous anthropogenic deposits that reflect Glasgow’s industrial heritage, over coal-bearing Palaeozoic bedrock succession deformed by multiple faulting episodes. As such, the geology poses significant interpretive challenges for planners, regulators and engineers. The depth dimension of conventional geological maps is very hard for non-geologists to appreciate. As a result, decision makers rarely take full account of geoscience issues in planning and development; nor do they fully exploit potential subsurface assets. With the advances of 3D hardware and software, it is now possible to combine disparate geoscience data types for a wide range applications and scenarios and to display these data effectively, and in ways that non-geologists can easily understand and use to inform their decisions. Using several 3D modelling packages, but primarily GSI3D and GOCAD® workflows in tandem, we have created 3D models designed to ‘nest’ within each other. Lower resolution regional models (c.1:50,000-scale equivalent) therefore provide the context for higher resolution (1:10,000-scale equivalent), and ultimately site-specific, models. The geological framework models have been attributed with a wide range of parameters such as permeability, aquifer productivity and various engineering properties. They have also been exported to flow modelling packages to model time-series processes such as recharge and flow of groundwater and will be used to model migration of contaminant plumes and carbon dioxide. Man-made objects, such as tunnels and mine workings have been embedded as 3D objects and placed into the 3D geological framework so their relationships to faults and other geological structures can be examined. The models are already assisting in the design and layout of new subsurface infrastructure such as buried utilities, tunnels, and underground storage, as part of Glasgow’s regeneration and redevelopment. They will also help to accurately quantify resources and enable their sustainable exploitation (e.g. aggregates, coal). In particular, the models provide an excellent basis for assessing the sustainable extraction of heat, using ground source heat pumps, from mine waters in Glasgow’s extensive network of abandoned mines. 3D modelling is therefore placing geoscience data and knowledge at the heart of the decision making process. With these data in forms that are interoperable with existing 3D models of surface infrastructure, the vision of an integrated 3 dimensional surfaces and subsurface approach to future city-scale planning is becoming achievable

Reinterpreting the age of the uppermost ‘Old Red Sandstone’ and Early Carboniferous in Scotland

In Scotland the base of the Ballagan Formation has traditionally been placed at the first grey mudstone within a contiguous Late Devonian to Carboniferous succession. This convention places the Devonian-Carboniferous boundary within the Old Red Sandstone Kinnesswood Formation. The consequences of this placement are that the tetrapods from the Ballagan Formation were dated as late Tournaisian in age and that the ranges of typically Devonian fish found in the Kinnesswood Formation continue into the Carboniferous. The Pease Bay specimen of the fish Remigolepis is from the Kinnesswood Formation. Comparisons with its range in Greenland, calibrated against spores, shows it to be Famennian in age. Detailed palynological sampling at Burnmouth from the base of the Ballagan Formation proves that the early Tournaisian spore zones (VI and HD plus Cl 1) are present. The Schopfites species that occurs through most of the succession is S. delicatus rather than S. claviger. The latter species defines the late Tournaisian CM spore zone. The first spore assemblage that has been found in upper ‘ORS’ strata underlying the Ballagan Formation (Preston, Whiteadder Water), contains Retispora lepidophyta and is from the early latest Famennian LL spore zone. The spore samples are interbedded with volcaniclastic debris which shows that the Kelso Volcanic Formation is, in part, early latest Famennian in age. These findings demonstrate that the Ballagan Formation includes most of the Tournaisian with the Devonian-Carboniferous boundary positioned close to the top of the Kinnesswood Formation. The Stage 6 calcrete at Pease Bay can be correlated to the equivalent section at Carham showing that it represents a time gap equivalent to the latest Famennian glaciation(s). Importantly some of the recently described Ballagan Formation tetrapods are older than previously dated and now fill the key early part of Romer’s Gap

Physical and genetic mapping in the grasses Lolium perenne and Festuca pratensis.

A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. In this line recombination occurs throughout the length of the F. pratensis/L. perenne bivalent. The F. pratensis chromosome and recombinants between it and its L. perenne homeologue can be visualized using genomic in situ hybridization (GISH). GISH junctions represent the physical locations of sites of recombination, enabling a range of recombinant chromosomes to be used for physical mapping of the introgressed F. pratensis chromosome. The physical map, in conjunction with a genetic map composed of 104 F. pratensis-specific amplified fragment length polymorphisms (AFLPs), demonstrated: (1) the first large-scale analysis of the physical distribution of AFLPs; (2) variation in the relationship between genetic and physical distance from one part of the F. pratensis chromosome to another (e.g., variation was observed between and within chromosome arms); (3) that nucleolar organizer regions (NORs) and centromeres greatly reduce recombination; (4) that coding sequences are present close to the centromere and NORs in areas of low recombination in plant species with large genomes; and (5) apparent complete synteny between the F. pratensis chromosome and rice chromosome 1

A demonstration of a 1:1 correspondence between chiasma frequency and recombination using a Lolium perenne/Festuca pratensis substitution

A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. The chromatin of F. pratensis and L. perenne can be distinguished by genomic in situ hybridization (GISH), and it is therefore possible to visualize the substituted F. pratensis chromosome in the L. perenne background and to study chiasma formation in a single marked bivalent. Recombination occurs freely in the F. pratensis/L. perenne bivalent, and chiasma frequency counts give a predicted map length for this bivalent of 76 cM. The substituted F. pratensis chromosome was also mapped with 104 EcoRI/Tru91 and HindIII/Tru91 amplified fragment length polymorphisms (AFLPs), generating a marker map of 81 cM. This map length is almost identical to the map length of 76 cM predicted from the chiasma frequency data. The work demonstrates a 1:1 correspondence between chiasma frequency and recombination and, in addition, the absence of chromatid interference across the Festuca and Lolium centromeres