Quantification of architectural variability and controls in an Upper Oligocene to Lower Miocene carbonate ramp, Browse Basin, Australia

Adding the missing third and fourth dimensions to trajectory analysis in carbonate systems

“…Key cause for retrogradation and intermediate‐scale along‐strike ramp margin variability in the Browse Basin Oligo‐Miocene carbonate system is the headward and downslope incision of channels into the ramp margin, which is likely triggered by syn‐sedimentary, small‐scale faults along the margin (Rinke‐Hardekopf, Reuning, Bourget, & Back, ; Tesch et al, ). In addition, SBT 5–6 and SBT 10–11 coincide with autogenic slope system re‐organization phases (Tesch et al, ): As the capacity of the slope system for basinward sediment transport is a function of slope channel number, width and depth, autogenic slope system re‐organization phases represent time intervals of increased basinward sediment bypass in excess of the transport capacity of the slope. This results in morphological instability of the slope system with a distinct shift in the slope channel number, width and depth as the slope system re‐equilibrates to accommodate the increased basinward sediment volume.…”

“…Age constraints from previous studies place the time duration for the 13 depositional sequences at ~1.4–1.8 Myr/sequence (Belde, Back, Bourget, & Reuning, ; Rosleff‐Soerensen et al, ; Tesch et al, ). Accommodation fill during the Oligo‐Miocene was dominated by autogenic carbonate sediment production of the cool‐water carbonate factory with <5% of siliciclastic sediment content in the study area (Rosleff‐Soerensen et al, ; Tesch et al, ). Tesch et al () flattened the seismic volume at the base of hemipelagic sediments that overly the Miocene reef complex to account for the effect of differential compaction.…”

“…Resulting limits of vertical and horizontal resolution in the seismic data at the Oligocene‐Miocene boundary are ~15 m and ~30 m respectively (Tesch et al, ). During the Oligocene to Lower Miocene, a distally steepened, strongly channelized heterozoan carbonate ramp developed in the Browse Basin, overlying Palaeocene and older fluvio‐deltaic siliciclastic strata (Figure ; Apthorpe, ; Reuning et al, ; Rosleff‐Soerensen, Reuning, Back, & Kukla, ; Stephenson & Cadman, ; Tesch et al, ). Age constraints from previous studies place the time duration for the 13 depositional sequences at ~1.4–1.8 Myr/sequence (Belde, Back, Bourget, & Reuning, ; Rosleff‐Soerensen et al, ; Tesch et al, ).…”

“…Accommodation fill during the Oligo‐Miocene was dominated by autogenic carbonate sediment production of the cool‐water carbonate factory with <5% of siliciclastic sediment content in the study area (Rosleff‐Soerensen et al, ; Tesch et al, ). Tesch et al () flattened the seismic volume at the base of hemipelagic sediments that overly the Miocene reef complex to account for the effect of differential compaction. The flattening decreased seismic reflection dip angles by less than 1°.…”

“…Location of Browse Basin data set on the North West Shelf of Australia with stratigraphic column of the Eocene to Miocene sedimentary system evolution from fluvio‐deltaic to rimmed carbonate shelf (modified from Tesch et al, ). Formation names from Woodside Energy (2008), and main EOD/lithology from Woodside Energy (1980) and Rosleff‐Soerensen et al ().…”