- Palaeotemperature constraints in Jabiru-1A derived from AFTA
and VR plotted against True Vertical Depth (EKB).
- Two major thermal episodes are recognised 225-160Ma (Middle
Triassic-Middle Jurassic) associated with an elevated palaeogeothermal
gradient and 30-15 Ma (Oligocene-Middle Miocene associated with
a palaeogeothermal gradient similar to that at the present-day
- Reconstructed thermal history of units preserved in Jabiru-1A
based on thermal history interpretation of AFTA and VR.
- Two palaeothermal episodes have been recognised, with cooling
beginning between 225 and 160 Ma (Middle Triassic to Middle Jurassic)
attributed to decline in basal heat flow combined with uplift
- Cooling beginning between 30 and 15 Ma (Oligocene - Middle Miocene)
attributed solely to uplift and erosion.
- Timing limits derived from AFTA samples in this well are shown
as the grey shading.
- Variation of maturity with time for Jabiru-1A derived from
the reconstructed thermal history, with the grey columns representing
the two major thermal episodes revealed by AFTA.
- The figure shows cessation of active source rock maturation
in the deeper section at 175 Ma (225-160 Ma allowed by AFTA) due
to cooling as a response to decline in basal heat flow and minor
(600m) uplift and erosion.
- The Tertiary thermal episode has no effect on the source rock
maturation history in the deeper section, as palaeotemperatures
during this episode were less than those during the Middle Triassic-Middle
Jurassic. However, subsequent burial did result in renewed maturation
in the shallower section, with cessation of active maturation
occurring between 30 and 15 Ma.
Basins Map || Arafura
|| Canning || McArthur
|| Bonaparte || Browse