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onlaps
Figure 32 shows a Cretaceous-Tertiary,
dominantly carbonate, 2 nd order cycle that
occurs over much of the Western Australian
offshore. Even at this highly condensed scale
we can see candidates for the component 3 rd
order SBs.
Fig. 32.
Figure 33 shows another 2 nd order cycle-Tertiary
clastics (with some volcanics) in the Taranaki
Basin, offshore the North Island, New Zealand.
Here the best fans are the early ones-as seen in
Brazil, North Africa, West Africa, Gulf of Mexico
inter alia.
Figures 34 (uninterpreted) and 35 (interpreted)
show an excellent 2 nd order Tertiary clastic cycle
in SE Asia. As seen in most examples the 2 nd
order fan is better developed that the 3 rd order
fans in the 2 nd order HST.
Fig. 33.
Figure 36 shows the Exxon log (gamma) model
(described in earlier Onlap articles in PNR) with
a 2 nd order log cycle from the entire Neocomian
Barrow Group of the Exmouth Sub-basin,
Western Australia. The massive 2 nd order fan
complex (in orangey-brown) is composed of
many 3 rd order fans stacking together. (These
fans are spectacular with one of the youngest
being deposited 60+ km from its coeval shelf
edge).
Fig. 34.
Figure 37 shows the Barrow 2 nd order cycle
on seismic. The yellow basal unit is a gigantic
undrilled (?) 2 nd order fan complex overlain by
the 2 nd order HST slope facies (grey) and 2 nd
order fluvial-deltaics (orange).
Figure 38 is a more unusual 2 nd order fan cycle,
from the Barrow Group in the Barrow Sub-basin
Fig. 35.
Fig. 37.
Fig. 36.
December 2012 / January 2013 | PESA News Resources | 47