Hydrocarbon traps within passive-margin evolution of Louisiana

Conference · Wed Sep 01 00:00:00 EDT 1993 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:6965661

Lavoie, D ^[1]; Lowrie, A

---

1. Steenis Space Center, MS (United States)

The evolutionary dynamics of the Louisiana continental margin as applied to the Neogene to present are sufficiently well understood that we present a preliminary model. The external components influencing the geologic evolution are sediment input (amount, type, and transport mechanisms) and sea level oscillations (periodicity and range). The internal dynamics are subsidence (rate, total amount, and location), salt tectonics (type and rate of motion), and sediment deposition (amount, type and mechanisms). The model presented is restricted geographically to the offshore region, from the shelf to the Sigsbee Escarpment, and temporally during the Neogene, the past 20 m.y. The notion that tectonic periodicity controls the evolutionary dynamics is integral to the model. The general loci of maximal deposition and tectonics are dictated by Milankovitch fourth-order cycles ranging from 1 x 10[sup 4] to 1 x 10 [sup 5] yr. superimposed on third-order cycles of up to 1 to 2 x 10[sup 6]yr. This model suggests a highly energetic phase in overall continental margin evolution during which the Sigsbee salt wedge migrated past an arbitrary fixed reference point, changing the physiography from lower slope to shelf. The energetic phase, which lasts between 2 and 4 m.y., separated two much longer phases are the drift phase, characterized by sedimentation along lower continental rises and abyssal plains, and a depositional phase, generally minor, and erosion along the shelf, coastal plain, and interior basins. This latter phase is characterized by regional subsidence and [open quotes]catch-up[close quotes] deposition as equilibrium along the continent is maintained. We also discuss hydrocarbon traps and their ephemeral nature with the overall continental margin.

• OSTI ID: 6965661
• Report Number(s): CONF-9310237-; CODEN: AABUD2
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 77:9; Conference: American Association of Petroleum Geologists (AAPG) mid-continent section meeting, Amarillo, TX (United States), 10-12 Oct 1993; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
CONTINENTAL MARGIN
GEOLOGIC MODELS
SEDIMENTATION
HYDROCARBONS
GEOLOGIC TRAPS
SEA LEVEL
VARIATIONS
LOUISIANA
TECTONICS
DEVELOPED COUNTRIES
LEVELS
NORTH AMERICA
ORGANIC COMPOUNDS
USA
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration