10.6084/m9.figshare.3454259.v1
Angelos Mavromatidis
Angelos
Mavromatidis
Richard Hillis
Richard
Hillis
Quantification of exhumation in the Eromanga Basin and its implications for hydrocarbon exploration
Geological Society of London
2016
compaction
exhumation
Eromanga Basin
hydrocarbon exploration Exhumation
porosity
overcompaction
Geology
2016-06-21 12:00:31
Dataset
https://geolsoc.figshare.com/articles/dataset/Quantification_of_exhumation_in_the_Eromanga_Basin_and_its_implications_for_hydrocarbon_exploration/3454259
<p>Exhumation in the Eromanga Basin of South Australia and Queensland has been quantified using compaction methodology. All methods
of estimating exhumation utilize rock properties that are affected by, and retain a memory of, burial in excess of that presently
observed. The tool used for estimating the exhumation in this study is analysis of the degree of overcompaction of rock units.
Since porosity describes compaction state, the sonic log, controlled strongly by the amount of porosity, is an appropriate
indicator of compaction and, hence, is used for quantifying exhumation from compaction. The standard method of estimating
exhumation based on the degree of overcompaction of a single shale unit has been modified, and seven units, predominantly
shales ranging in age from the Cretaceous to the Jurassic, have been analysed. All units yield similar results. Burial at
depth greater than currently observed is the most likely cause of overcompaction since it is unlikely that sedimentological
and/or diagenetic processes are responsible for similar amounts of overcompaction in different lithologies. The results of
the compaction analysis reveal that Late Cretaceous–Tertiary exhumation increases eastwards from the Patchawarra Trough, through
the Gidgealpa–Merrimelia–Innamincka Trend and Nappamerri Trough into the Queensland sector of the basins. This study has major
implications for hydrocarbon exploration. Predicted maturation of source rocks will be greater for any given geothermal history
if exhumation is incorporated in maturation modelling. The exhumation study helps to quantify velocity anomalies associated
with overcompaction. Exhumation values can also be used to improve porosity predictions of reservoir units in undrilled targets.
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