Abstract: Comparison of Two Miocene Turbidite Intervals: Taranaki Basin (New Zealand) and Gulf of Mexico Basin (GOM) (USA)

COLEMAN, JAMES L.
Jr, Amoco Worldwide Exploration Business Group, 501 WestLake Park Blvd, Houston, Texas, U.S.A. 77079-2696;
GREG H. BROWNE
Institute of Geological and Nuclear Sciences, Ltd., P.O. Box 30 368, Lower Hutt, New Zealand (IGNS);
ROGER M. SLATT
Colorado School of Mines, Golden, Colorado, U.S.A. 80401-1887 (CSM);
GEORGE R. CLEMENCEAU
Amoco Offshore Business Group, 1340 Poydras Street, New Orleans, U.S.A. 70112

Comparison of two different Miocene deep water depositional systems enable a better understanding of both systems. The Mt. Messenger Fm. (MMF) of the Taranaki Basin (TB) (NZ) is an overall prograding submarine fan complex adjacent to an active, submarine volcano-punctuated basin margin. Miocene of the Viosca Knoll/ Mississippi Canyon (VK/MC) area of the GOM is an overall prograding passive margin submarine fan complex deposited within an active salt dome basin. The active margin nature of the TB affords an opportunity to observe basin floor through slope depositional systems tracts in outcrop along the sea cliffs of the North Taranaki coast. This outcrop ties into nearby well and seismic data.

The thick upper and middle Miocene of the VK/MC GOM is known only from subsurface data. Relatively thin turbidite sand packages are present, but appear to be in the minority, with thick muddy debris flow intervals dominating much of the section. The VK/MC area was part of the main Mississippi River depocenter during the middle and late Miocene.

This difference may be attributed to the different tectonic and sedimentologic natures of the two depositional areas. During the Miocene the TB was a tectonically and seismically active area, where earthquake shocks could have increased the fluidization potential of the MMF precursor sediments producing a dominance of turbidites. The VK/MC area is controlled by salt dome tectonics within the high outfall area of the Mississippi River slope, an area of lower seismic activity and higher sedimentation - hence, a mixture of debrites and turbidites.

AAPG Search and Discovery Article #90932©1998 GCAGS/GCS-SEPM Meeting, Corpus Christi, Texas