We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Use of <sup>40</sup>Ar/<sup>39</sup>Ar K-feldspar thermochronology in basin thermal history reconstruction: an example from the Big Lake Suite granites, Warburton Basin, South Australia.
- Authors
McLaren, Sandra; Dunlap, W. James
- Abstract
The potential use of 40Ar/39Ar thermochronologic data from K-feldspars in reconstructing basin thermal history has been evaluated using the example of the Warburton/Cooper/Eromanga Basin, Australia's largest onshore oil- and gas-producing basin. Results from 40Ar/39Ar step-heating experiments reveal details of the evolution of the basin system, including the following: (1) the operation of high geothermal gradient regimes during the earliest basin evolution, suggesting that basin formation was active rather than passive; (2) slow cooling from a Permo-Triassic temperature peak of at least 250–300°C; (3) a rise in thermal gradients to contemporary bottom hole temperatures in the last 5–10 Myr; and (4) spatially variable recrystallization events between 100 and 50 Ma and at around 20 Ma. Initial microstructural observations serve as a useful predictor of the quality and nature of the obtainable age information. Data from ‘pristine’ K-feldspars may constrain the peak temperature conditions experienced in the basin, the basin's early thermal history and also any recent changes in thermal gradient. Contrasting data from texturally modified K-feldspars may constrain times of thermal transients and/or fluid flow, with the preferred interpretation that K-feldspars recrystallize in response to such events. The Warburton/Cooper/Eromanga Basin example suggests that the 40Ar/39Ar technique may serve as a useful adjunct to apatite and zircon fission track analysis and conventional organic maturation indices in basin thermal history analysis.
- Subjects
GEOLOGICAL basins; THERMAL analysis; CHEMICAL oceanography; ARGON; GRANITE; FELDSPAR; CRYSTALLIZATION
- Publication
Basin Research, 2006, Vol 18, Issue 2, p189
- ISSN
0950-091X
- Publication type
Article
- DOI
10.1111/j.1365-2117.2006.00288.x