Oxygen Isotope Geothermometry of Diagenetically Altered Shales
Published:January 01, 1979
The maximum temperature to which a shale has been heated as a result of burial can, in some instances, be estimated using oxygen isotope geothermometry. The isotopic fractionation, or difference between O<sup>18</sup>/O<sup>16</sup> ratios of two coexisting minerals which have reached isotopic equilibrium with one another, is temperature dependent. Hence, if two coexisting minerals, which have isotopically equilibrated with one another, can be separated from a shale, and if the variation of the equilibrium isotopic fractionation between these minerals is known, the temperature of equilibration can-be estimated.
Quartz and coexisting illite or mixed layer illite/smectite is a promising pair for...
Figures & Tables
Aspects of Diagenesis
There are a number of gaping holes in accumulated knowledge within the discipline of sedimentology. Perhaps one of the largest holes has been the general subject of diagenesis in clastic rocks. It was therefore fortuitous that two symposia covering various aspects of diagenesis (mainly in clastics) were presented a year apart in different parts of the country but with the same motivation – to contribute to the closing of that knowledge gap. Sedimentologists now have a fairly good idea of the what and the how of sediment deposition. What happens after the sediments are lithified has frequently been ignored. It was the aim of both editors of this publication to approach the subject from two different viewpoints. Schluger directed a symposium which looked mainly at clastic reservoirs, and Scholle presented a symposium which examined various aspects of paleotemperature control of diagenesis.