Publication Name: PESA Journal No. 25
Authors: Xiaowen Sun
Publication Volume: 25
Date Published: December 1987
Number of Pages: 26
Reference Type: Journal Article
Abstract:
Detailed facies analysis of the lower Kalladeina Formation,by interpreting well and seismic data, leads to the
reconstruction of Middle to Late Cambrian carbonatedominated
depositional environments in the eastern
Warburton Basin. Two contrasting shallow-water carbonate
platform to deep-water slope to basin depositional systems
can be established from seven facies assemblages indicating
inner shelf, peritidal, shoal, shelf edge, foreslope, slope
apron and basin environments. The peritidal platform is
dominated by dolomitised limestone and rare siliciclastics.
Localised mounded carbonate build-ups and a linear shelf
edge are delineated seismically. Below the inferred shelf
edge, the slope apron to basin was starved of in situ
sediments but received carbonate and basaltic turbidites,
and chaotic debris flow deposits derived from the shelf
margin and foreslope. Preliminary palaeogeography during
the Middle and Late Cambrian permits the location of
potentially excellent dolomitised and karstic reservoirs in
the carbonate build-ups and on the shelf edge. A vuggy
dolomite unit is interpreted to have been originally
deposited in a shallow shelf environment. Stratigraphic
traps may form between grainy build-ups and encasing
muddy facies, and also between vuggy dolomites and
overlying transgressive shales. Recognition of thick, mudfree
carbonates at unconformities will delineate buried hill
type reservoirs capable of trapping petroleum sourced from
the Cooper Basin.