Introduction, Objectives, and Principal Results of Deep Sea Drilling Project Leg 96

Bouma, Arnold H.; Coleman, J.M.; Meyer, A.

doi:10.2973/dsdp.proc.96.102.1986

Cited by 16 publications

(35 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DSDP drill cores from elsewhere on the fan (Bouma et al 1986) were also completely or partially relogged at a scale of 1:5. These much longer drill cores are located: (i) adjacent to or within the proximal part of the main fan channel, (ii) within the eastern Walker-Massingill Slump(s), and (iii) beyond the junction of the main channel and secondary feeder channel (Fig.…”

Section: Core Descriptionmentioning

confidence: 99%

How Did Thin Submarine Debris Flows Carry Boulder-Sized Intraclasts for Remarkable Distances Across Low Gradients to the Far Reaches of the Mississippi Fan?

Talling¹,

Wynn²,

Schmmidt³

et al. 2010

Journal of Sedimentary Research

View full text Add to dashboard Cite

Submarine density flows dominate sediment transport into many parts of the ocean and form submarine fans, which are some of the largest sediment accumulations on Earth. Previous studies often assumed that the distal fringes of submarine fans would be dominated by extensive sheet-like deposits from dilute and expanded turbidity currents, because only turbidity currents would transport large volumes of sediment for long distances across such low gradients. Deposits with a remarkable frondlike shape occur at the furthest fringe of the Mississippi submarine fan. Understanding the emplacement process of these deposits is important because their frondlike shape suggests deposition from debris flows rather than turbidity currents. Previous analyses concluded that these deposits comprise a complex arrangement of thin interbedded turbidity current and debris flow deposits. Here we propose a different internal geometry for the frondlike deposits. Intervals previously described as in place turbidites are interpreted to be clasts within a single debrite interval that is , 1 to 2 m thick. This debrite interval is underlain by clean sand. The debrite interval could have been emplaced by multiple debris flows, or one event comprising multiple pulses. Clasts in the debrite interval are much bigger than previously thought, including boulders with diameters that can exceed 50 cm. We show that thin (, 2 m) and extremely fluidal debris flows could have carried these boulders across gradients of only 0.06u to the fringes of one of the world's largest submarine fans, without hydroplaning. This long transport distance could occur if the density of the clasts was less than that of the surrounding debris flow. Emplacement of the basal clean sand layer appears closely linked to debris flow deposition because the clean sand layer pinches out in a location similar to that of the overlying debrite. We therefore suggest that the basal clean sand most likely settled out from the overlying debris flows, and that the clean sand is not a fore running turbidity current deposit. Shearing at the base of a mud-rich debris flow would most likely produce a muddy basal sand interval, rather than the clean sand that is observed. This basal sand interval is therefore less likely to be a record of a lubricating layer with high-pore-fluid-pressure on which the debris flows moved. This study shows how thin and highly mobile debris flows can redistribute large volumes of sediment including bouldersized clasts long distances into the deep ocean across remarkably low gradients.

show abstract

Section: Core Descriptionmentioning

confidence: 99%

How Did Thin Submarine Debris Flows Carry Boulder-Sized Intraclasts for Remarkable Distances Across Low Gradients to the Far Reaches of the Mississippi Fan?

Talling¹,

Wynn²,

Schmmidt³

et al. 2010

Journal of Sedimentary Research

View full text Add to dashboard Cite

show abstract

“…An example quoted by Boyd et al (1989) is the Mississippi Delta, which extends down-dip into a submarine fan consisting of several lobes. According to Coleman et al (1983) and Bouma et al (1986), these lobes were formed during Quaternary sea level lowstands from sediments supplied by the ancient Mississippi River and then conveyed through a submarine canyon to the fan.…”

Section: Basic Concepts Of Sequence Stratigraphymentioning

confidence: 99%

Coal-Bearing Depositional Systems

Diessel¹

1992

401

416

View full text Add to dashboard Cite

“…From 5 meter long drop core samples, Brooks and Bryant (22) recovered samples of hydrates from the seafloor across the Gulf of Mexico slope in water depths greater than about 1600 ft. Hydrates were also recovered at significant depths below the mudline during DSDP Leg 96 drilling in the Orca Basin on the Texas/Louisiana Slope (10).…”

Section: Gas Hydratesmentioning

confidence: 97%

“…According to the results of DSDP Leg 96 Site 615 boring, a portion of the fan overlaps an 84-ft thick calcareous ooze layer derived from the Florida slope (10). The sensitivity is probably due to the breakdown of a cementing agent at relatively small strains.…”

Section: Sensitive Claysmentioning

confidence: 99%

“…Also, during DSDP Leg 96 exploration of the Mississippi Fan, gravel layers were sampled 700 ft below the seabed in water depths of 8,183 ft; sand strata were recovered 90 ft below the seabed in water depths of 10,869 ft (10). Martin and Bouma (5) describe a 60-ft thick sand in 3600 ft of water at a location adjacent to the Gyre Basin.…”

Section: Sand and Rock Sand Strata Locations And Propertiesmentioning

confidence: 99%

See 1 more Smart Citation