Sequence Stratigraphy of Neogene Turbidite Systems, Northern Green Canyon and Ewing Bank, Northern Gulf of Mexico

Abstract

The Ncogene turbidite systems of Green Canyon and Ewing Bank lease areas in the northern Gulf of Mexico are amajor exploration play. The regional sequence stratigraphy for this area has been interpreted to help define the potential areas for future exploration. Data base consists of 6300 miles of 2-D multifold seismic data well log data for 175, wells, and biostratigraphy from 180 wells. Four main intervals have been identified, which reflect different kinds of turbidite systems based upon lithologies and seismic facies. Exploration concepts must be different in each of the four intervals because of the different nature of the turbidite systems. Paleoecology data indicate that deposition of these turbidite systems occurred in bathyal water depths. Lower Pliocene sediments (5.5 to 3.0 Ma) include the 5.5, 4.2 and 3.8 sequence boundaries. The interval consists of sandrich turbidite systems. The upper Pliocene interval (3.0 to 1.4 Ma) comprises the 3.0, 2.6, 2.4, 1.9 sequence boundaries. The interval is thin in the eastern portion of the area and becomes thicker to the west. Sands develop only in the western portion of the area. The interval corresponds to when the Mississippi River avulsed to farther in the western Gulf of Mexico and sediment supply decreased significantly. The lower Pleistocene interval (1.4 to 0.7 Ma) includes the 1.4, 1.1 and 0.8 Ma sequence boundaries. The interval is predominantly shale-rich with localized sands developing in channel-levee systems and unchannelized sands. The upper Pleistocene interval (0.7 Ma to Present) consists of shale-dominated turbidite systems. Notable submarine canyons develop in this interval to the east.

Controls on Mesozoic rift-related uplift and syn-extensional sedimentation in the Exmouth Plateau

“…The area is a highly productive Australian hydrocarbon province (Gartrell, 2000). The Exmouth Plateau is a broad subsided continental platform outboard of the main depocentres of the Northern Carnarvon Basin (Falvey and mutter, 1981;Purcell and Purcell, 1988;Wulff and Barber, 1995). The two dominant structural trends, orientated north and the northeast, vary across the plateau reflecting the interaction of basement contacts and oblique extension (Stagg et al, 2004).…”