HR: 0800h
AN: T21C-0505    [Abstracts]
TI: Putting the geology back into Earth models
AU: McCaffrey, K
EM: k.j.w.mccaffrey@durham.ac.uk
AF: Reactivation Research Group, Department of Earth Sciences University of Durham, Durham, DH13LE United Kingdom
AU: McCaffrey, K
EM: k.j.w.mccaffrey@durham.ac.uk
AF: Geospatial Research Ltd, Dept of Earth Sciences, University of Durham, Durham, DH13LE United Kingdom
AU: * Imber, J
EM: jonathan.imber@durham.ac.uk
AF: Reactivation Research Group, Department of Earth Sciences University of Durham, Durham, DH13LE United Kingdom
AU: Holdsworth, R
EM: r.e.holdsworth@durham.ac.uk
AF: Reactivation Research Group, Department of Earth Sciences University of Durham, Durham, DH13LE United Kingdom
AU: Holdsworth, R
EM: r.e.holdsworth@durham.ac.uk
AF: Geospatial Research Ltd, Dept of Earth Sciences, University of Durham, Durham, DH13LE United Kingdom
AU: Clegg, P
EM: p.clegg@durham.ac.uk
AF: Reactivation Research Group, Department of Earth Sciences University of Durham, Durham, DH13LE United Kingdom
AU: De Paola, N
EM: Nicola De Paola depaola@unipg.it
AF: Reactivation Research Group, Department of Earth Sciences University of Durham, Durham, DH13LE United Kingdom
AU: Jones, R
EM: r.r.jones@durham.ac.uk
AF: Geospatial Research Ltd, Dept of Earth Sciences, University of Durham, Durham, DH13LE United Kingdom
AU: Hobbs, R
EM: r.w.hobbs@durham.ac.uk
AF: e-Science Research Institute, University of Durham, Durham, DH13LE United Kingdom
AU: Holliman, N
EM: n.s.holliman@durham.ac.uk
AF: e-Science Research Institute, University of Durham, Durham, DH13LE United Kingdom
AB: Geological architectures span at least 12 orders of magnitude length-scale from individual microstructures to lithospheric plates. Traditional paper-based geological mapping and fieldwork techniques have not been able to accurately capture the geospatial properties of mesoscale features in surface outcrops. In addition, geophysical imaging of the subsurface is poor at these length scales. This lack of fine-scale spatial precision has meant that the superbly detailed lithological units and structures we see in surface outcrops have not been integrated directly into predictive numerical and analogue models. As a result, models created to simulate mesoscale geology are currently not well calibrated to natural datasets and it is therefore difficult to demonstrate even partial confirmation of predictive, three dimensional (3D) models. This creates significant problems for industrial users interested in the extraction or storage of fluids in subsurface reservoirs, since accurate predictions of these processes rely critically on a complete 3D understanding of the subsurface mesoscale geology. Terrestrial laser scanners and Real Time Kinematic (RTK) GPS units are the principal tools used to capture digital data from surface outcrops. Automatic data collection involves scanning the outcrop surface with a laser to capture the topography with a cm-spaced grid of spatial coordinates in x,y and z. Using built-in digital cameras, the most recent laser scanners collect registered photographs that allow the software to colour the points to match the outcrop, and produce a photo-realistic 3D image. Laser scanning works best on cliff sections or in mines and quarries where the scanner can be placed directly in front of the outcrop. With RTK GPS data collection, any measurable attribute (surface dip, strike, lithology) can be recorded together with the spatial coordinates at a user-controlled sample spacing down to c. 5 cm. As the method is GPS-based, it works best on sub-horizontal outcrop surfaces with an unobstructed view of the sky. Photographs can be draped onto the topographic surfaces created using RTK GPS allowing the surface geology to be analysed in detail within an immersive 3D visualisation environment. An additional advantage is that these outcrop-scale data can be easily integrated into a single standardised database, e.g. a 3D Geographical Information System (GIS) and combined with other geological or geophysical datasets collected across a range of scales. Our examples show how digital datasets provide a 3D geological model that can be used to calibrate mesoscale numerical and analogue models in the same way that geophysical datasets (seismic reflection, gravity and magnetics) are used to constrain lithosphere geodynamic and basin models.
DE: 0545 Modeling (4255)
SC: Tectonophysics [T]
MN: Fall Meeting 2005