04-16-2014, 09:15 PM
Reef Complex formation in eastern Papuan Basin
“In Eocene times, a passive margin was still established in the Papuan Basin. The Australian carton was emergent to the south and southwest, and a temperate carbonate platform formed a rim in the shallow water around its edges (Mendi Limestone). Deeper water (abyssal plain) existed further to the north and east (Aure Formation). The Middle Oligocene saw the Australian Craton and Melanesian Arc start to converge. The slow collision of these two regions transformed Papuan passive margin into a foreland basin. By the Early Micoene, this transition had created a narrow foredeep, and a southward moving transgression that greatly expanded the width of the carbonate platform... it is interpreted that barrier reefs (Borabi trend) became established along the margins of the platform near the shelf edge. Large reefs were also established on structural highs in front of the main trend (three of these, the Uramu, Pasca and Pandora reefs, located offshore in the Gulf of Papua, contain significant gas resources). With continued loading from the thrust sheet to the north, the basin deepened and sediment influx increases. This caused backstepping of the reef trends into shallower, cleaner waters to the south.”
– GLJ Petroleum Consultants 12/31/09
“In Eocene times, a passive margin was still established in the Papuan Basin. The Australian carton was emergent to the south and southwest, and a temperate carbonate platform formed a rim in the shallow water around its edges (Mendi Limestone). Deeper water (abyssal plain) existed further to the north and east (Aure Formation). The Middle Oligocene saw the Australian Craton and Melanesian Arc start to converge. The slow collision of these two regions transformed Papuan passive margin into a foreland basin. By the Early Micoene, this transition had created a narrow foredeep, and a southward moving transgression that greatly expanded the width of the carbonate platform... it is interpreted that barrier reefs (Borabi trend) became established along the margins of the platform near the shelf edge. Large reefs were also established on structural highs in front of the main trend (three of these, the Uramu, Pasca and Pandora reefs, located offshore in the Gulf of Papua, contain significant gas resources). With continued loading from the thrust sheet to the north, the basin deepened and sediment influx increases. This caused backstepping of the reef trends into shallower, cleaner waters to the south.”
– GLJ Petroleum Consultants 12/31/09