GALLAGHER, KERRY, T.H. Huxley School of Environment, Earth Sciences and Engineering, Imperial College, South Kensington, London, SW7 2AS, England; ANDREW CARTER, ANTHONY HURFORD, Dept. of Geological Sciences, University College London, Gower St, London WC1 E, England; KIT JOHNSON,T.H. Huxley School of Environment, Earth Sciences and Engineering, Imperial College, South Kensington, London, SW7 2AS, England; RUTH SIDDALL Dept. of Geological Sciences, University College London, Gower St, London WC1 E, England
Abstract: Sediment Supply to the Margin of N.W. Europe - Constraints from the Onshore Denudation Chronology
Tectonically active areas have long been studied in terms of cooling and exhumation. On passive margins, however, the rates of long term regional denudation are poorly constrained, yet are important in terms of sediment budgets and tectonic evolution. One technique capable of constraining long term denudation is apatite fission track analysis as the data record shallow level cooling histories, appropriate to the upper few km of the Earth's crust.
A fission track database
of over 600 samples exists for NW Europe between the Alps, the Pyrenees,
Ireland and Scotland.These data can be correlated with structures and surface
geology. However, a more useful application of this database is as constraint
for models of the cooling and denudation histories. We have modelled the
thermal history of each datum individually, combining the results with
other spatial geophysical data sets, such as heat flow, to produce computer
animations of the denudation history or cooling rates as a function of
space and time. These new visual representations of allow a rapid assessment
of the regional denudation history. Moreover, the model results can be
used within a specified region to constrain the volume of detritus derived
or average debudation rate as a function of time. These denudation chronology
estimates may be correlated with sediment volumes and rates of deposition
in nearby sedimentary basins to construct a more complete picture of the
geological evolution of a region.We illustrate the application of these
modelling techniques to the NW European fission track database.
AAPG Search and Discovery Article #90923@1999 International Conference and Exhibition, Birmingham, England