--> Abstract: Estimates of Uplift and Erosion from Thermal History Information, by D. C. Arne, I. R. Duddy, P. F. Green, K. A. Hegarty, and G. M. Laslett; #91012 (1992).

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ABSTRACT: Estimates of Uplift and Erosion from Thermal History Information

ARNE, D. C., I. R. DUDDY, and P. F. GREEN, Geotrack International, Melbourne, Australia, K. A. HEGARTY, Geotrack International, Houston, TX, and G. M. LASLETT, Geotrack International, Melbourne, Australia

The combined application of apatite fission track analysis (AFTA) and vitrinite reflectance measurement (VR) places important constraints on both the timing and magnitude of uplift and erosion for samples in vertical well sequences that show evidence of cooling, either following deposition of the youngest preserved sediment intersected by the well or across major regional unconformities within the sequence.

By obtaining estimates of maximum paleotemperatures over a range of depths, the paleogeothermal gradient prior to cooling can be constrained. This information is then used to estimate the amount of section removed from the observed degree of cooling from maximum paleotemperatures to present-day temperatures. Maximum paleotemperatures are constrained by AFTA for paleotemperatures up to 150%C, while VR data are used to constrain maximum paleotemperatures over a greater temperature range using the distributed activation energy model of Burnham and Sweeney (1989). AFTA also places unique constraints on the time of cooling from elevated paleotemperatures in situations where it cannot be obtained from VR profiles alone.

This approach is subject to uncertainties associated with the estimation of maximum paleotemperatures, present-day temperatures, and the depth range over which the paleogeothermal gradient can be constrained. Where these uncertainties can be minimized, reliable estimates of uplift and erosion can be obtained and burial models improved, as demonstrated by the statistical assessment of estimates from several examples.

 

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)