Seismic Stratigraphy Of The Tertiary Sediments In The Dampier Sub-Basin And On The Rankin Platform, North West Shelf, Western Australia.
Stockmann, Janet E.
Honours Degree, 1987
University of Adelaide
The Tertiary sediments in the Dampier Sub-basin and over the Rankin Platform, on the North West Shelf of Western Australia can be subdivided into six sequences, as follows:
- The Palaeocene Sequence,
- The Lower Eocene Sequence,
- The Middle and Upper Eocene Sequence,
- The Oligocene Sequence,
- The Lower Miocene Sequence, and
- The Middle and Upper Miocene Sequence.
Each of the sequences prograde in a northwesterly direction, and in the process the shelf is extended in the same direction. The internal seismic character of the sequences delineates the position of the shore, the shelf, the shelf edge and the slope. Lateral variations in sediment type occur from the shore to the slope. The nature of the sediments in the sequences are also controlled by the amount of clastic input into the basin from shore drainage.
The areal extent and thicknesses of the six Tertiary sequences listed above is largely controlled by the regional subsidence history of the North West Shelf passive margin and sea level changes during this period. However structural movement along existing fault blocks, such as the Rankin Platform, also had an influence, though more subtle.