Molecular Indicators of Geothermal History
Clifford C. Walters, Paul G. Lillis, Kenneth E. Peters, 2012. "Molecular Indicators of Geothermal History", Analyzing the Thermal History of Sedimentary Basins: Methods and Case Studies, Nicholas B. Harris, Kenneth E. Peters
Download citation file:
Many basin simulators include the option to use calculated biomarker ratios from published first-order kinetic parameters as a means to calibrate thermal history. Published kinetic parameters for many biomarker reactions are based on simplistic and unfounded assumptions of reaction pathways, lack the needed precision, or have insufficient documentation to evaluate their effectiveness. We believe that calibrations of thermal history based on biomarker ratios are less reliable than those based on more common methods, such as vitrinite reflectance and corrected bottom-hole temperatures, because of uncertainty in the reaction mechanisms and kinetic parameters. Some research indicates that certain reactions, such as cyclization of ortho-substituted biphenyls and thermal decomposition of alkyl esters, could provide useful kinetics with which to calibrate basin models, but these efforts have not been pursued by the geochemical community.
Figures & Tables
Thermal histories of sedimentary basins are critical sources of scientific and practical information. They provide us with windows into past and present tectonic processes and the configuration of the crust and mantle. Using records of present and past temperature distributions, we can identify and constrain interpretations of tectonic events, distinguish different basin types and interpret pathways of fluid flow. These insights can be used calibrate basin and petroleum system models and to interpret and predict the distribution of minerals and petroleum, diagenesis and reservoir quality, and the geomechanical properties of rock units. This volume summarizes the current state of the art for many modern approaches used to estimate paleotemperature. Many techniques are now available based on both organic and inorganic components in the rock. Even techniques that are now many years old, such as apatite fission track analysis, have und