Geotechnical Properties of Intraslope Basin Sediments, Gulf of Mexico, Deep Sea Drilling Project Leg 96, Site 619

Bryant, William R.; Wetzel, Andreas; Sweet, William E.

doi:10.2973/dsdp.proc.96.153.1986

Cited by 4 publications

(3 citation statements)

References 4 publications

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“…Original maps of Bouma et al (1986) were digitized in UTM coordinates, and volumes calculated using GIS software. Sediment volumes were converted to sediment masses using grain density of 2,650 kg/m 3 , porosities from DSDP Leg 96 core data (Bryant et al, 1986) for core depths of 0-200 m below sea floor (bsf) , and depth-porosity relationships of Nobes et al (1986) Table 5. Details of discharge and duration for meltwater flood pulses (MWF) of Aharon (2003) and pauses in meltwater discharge to the GoM (P), with approximations of sediment delivery per pulse, using sediment concentration of 0.4 kg/m 3 for prehistoric loads, and 0.2 kg/m 3 for the 2011 flood (conservative ssc estimate from Heimann et al, 2011, and water discharge from US-ACE, 2012).…”

Section: Discussionmentioning

confidence: 99%

The Mississippi River source-to-sink system: Perspectives on tectonic, climatic, and anthropogenic influences, Miocene to Anthropocene

Bentley

Blum

Maloney

et al. 2016

Earth-Science Reviews

143

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The Mississippi River fluvial-marine sediment-dispersal system (MRS) has become the focus of renewed research during the past decade, driven by the recognition that the channel, alluvial valley, delta, and offshore regions are critical components of North American economic and ecological networks. This renaissance follows and builds on over a century of intense engineering and geological study, and was sparked by the catastrophic Gulf of Mexico 2005 hurricane season, the 2010 Deep Water Horizon oil spill, and the newly recognized utility of source-to-sink concepts in hydrocarbon exploration and production. With this paper, we consider influences on the MRS over Neogene timescales, integrate fluvial and marine processes with the valley to shelf to deepwater regions, discuss MRS evolution through the late Pleistocene and Holocene, and conclude with an evaluation of Anthropocene MRS morphodynamics and source-to-sink connectivity in a time of profound human alteration of the system. In doing so, we evaluate the effects of tectonic, climatic, and anthropogenic influences on the MRS over multiple timescales. The Holocene MRS exhibits autogenic process-response at multiple spatial and temporal scales, from terrestrial catchment to marine basin. There is also ample evidence for allogenic influence, if not outright control, on these same morphodynamic phenomena that are often considered hallmarks of autogenesis in sedimentary systems. Prime examples include episodes of enhanced Holocene flooding that likely triggered avulsion, crevassing, and lobe-switching events at subdelta to delta scales. The modern locus of the Mississippi fluvial axis and shelf-slope-fan complex was established by Neogene crustal dynamics that steered sediment supply. Dominant Miocene sediment supply shifted west to east, due to regional subsidence in the Rockies. Then, drier 3 conditions inhibited sediment delivery from the Rocky Mountains, and Appalachian epeirogenic uplift combined with wetter conditions to enhance sediment delivery from the Appalachians. Climatic influences came to the forefront during Pleistocene glacial-interglacial cycles. The fluvial system rapidly responded to sea-level rises and falls with rapid and extensive floodplain aggradation and fluvial knickpoint migration, respectively. More dramatically, meltwater flood episodes spanning decades to centuries were powerful agents of geomorphic sculpting and source-to-sink connectivity from the ice edge to the deepest marine basin. Differential sediment loading from alluvial valley to slope extending from Cretaceous to present time drove salttectonic motions, which provided additional morphodynamic complexity, steered deep-sea sediment delivery, diverted and closed canyons, and contributed to modern slope geometry. Despite the best efforts from generations of engineers, the leveed, gated, and dammed Mississippi still demonstrates the same tendency for self-regulation that confronted 19 th century engineers. This is most apparent in the bed-level aggradation and scour associated wit...

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Section: Discussionmentioning

confidence: 99%

The Mississippi River source-to-sink system: Perspectives on tectonic, climatic, and anthropogenic influences, Miocene to Anthropocene

Bentley

Blum

Maloney

et al. 2016

Earth-Science Reviews

143

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“… d References are as follows: a, Uchida et al [2000]; b, Kulenkampff and Spangenberg [2005]; c, Matsumoto et al [2000]; d, Collett and Wendlandt [2000]; e, Winters [2000a]; f, Winters [2000b]; g, Uchida et al [2004]; h, Taira et al [1991]; i, Yun et al [2010]; j, Collett et al [2008]; k, Winters et al [2008]; l, Hovland et al [1995]; m, Camerlenghi et al [1995]; n, Westbrook et al [1994]; o, von Huene et al [1987]; p, Kvenvolden and Kastner [1990]; q, Hill and Marsters [1990]; r, Tamaki et al [1990]; s, Holler [1992]; t, Yun et al [2011]; u, Kim et al [2011]; v, Kwon et al [2011]; w, Pflaunm et al [1985]; x, Thayer et al [1986]; y, Bryant et al [1986]; z, Boswell et al [2009]; aa, Luan et al [2008]; ab, Dang et al [2010]; ac, Stern et al [2011]; ad, Winters et al [2011]; ae, Dai et al [2011]; af, Yun et al [2006]; ag, Tan et al [2006]. …”

Section: Hydrate In Porous Media: Patternsmentioning

confidence: 99%

Hydrate morphology: Physical properties of sands with patchy hydrate saturation

et al. 2012

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.[1] The physical properties of gas hydrate-bearing sediments depend on the volume fraction and spatial distribution of the hydrate phase. The host sediment grain size and the state of effective stress determine the hydrate morphology in sediments; this information can be used to significantly constrain estimates of the physical properties of hydrate-bearing sediments, including the coarse-grained sands subjected to high effective stress that are of interest as potential energy resources. Reported data and physical analyses suggest hydrate-bearing sands contain a heterogeneous, patchy hydrate distribution, whereby zones with 100% pore-space hydrate saturation are embedded in hydrate-free sand. Accounting for patchy rather than homogeneous hydrate distribution yields more tightly constrained estimates of physical properties in hydrate-bearing sands and captures observed physical-property dependencies on hydrate saturation. For example, numerical modeling results of sands with patchy saturation agree with experimental observation, showing a transition in stiffness starting near the series bound at low hydrate saturations but moving toward the parallel bound at high hydrate saturations. The hydrate-patch size itself impacts the physical properties of hydrate-bearing sediments; for example, at constant hydrate saturation, we find that conductivity (electrical, hydraulic and thermal) increases as the number of hydrate-saturated patches increases. This increase reflects the larger number of conductive flow paths that exist in specimens with many small hydrate-saturated patches in comparison to specimens in which a few large hydrate saturated patches can block flow over a significant cross-section of the specimen.

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“…The rate of consolidation is controlled by how fast the pore-water can dissipate under a given pressure gradient. In marine settings, the factors that principally influence this consolidation process are depth of burial, grain size, porosity, and permeability (Taylor and Bryant, 1985;Bryant et al, 1986b). Porosity is a measure of the volume of voids in the sediment, and permeability depends on the interconnection (tortuosity) of these voids to achieve fluid flow through the sediment.…”

Section: Permeabilitymentioning

confidence: 99%

Sediment Consolidation and Permeability at the Barbados Forearc

Taylor¹,

Leonard²

1990

Proceedings of the Ocean Drilling Program

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Sediments cored from the Barbados Ridge accretionary complex at ODP Sites 671, 672, and 676 are progressively underconsolidated with depth. Very low measured intergranular permeabilities contribute substantially to the probable excess pore-water pressures that account for the underconsolidated behavior. The estimated pore pressures immediately overlying the incipient decollement at the reference site are nearly equal to the overburden stress. Data show that the pore fluids within the fine-grained sediments of the complex are absorbing the tectonic shock of underthrusting as they are accreted, effectively leading to "lubricated subduction" of the underthrust Oligocene and older sediments. Lateral compression and dewatering by fracture permeability is taking place in the accreted section despite apparent underconsolidation, resulting in limited pore-volume reduction and sediment strengthening from east to west on the ridge.

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Geotechnical Properties of Intraslope Basin Sediments, Gulf of Mexico, Deep Sea Drilling Project Leg 96, Site 619

Cited by 4 publications

References 4 publications

The Mississippi River source-to-sink system: Perspectives on tectonic, climatic, and anthropogenic influences, Miocene to Anthropocene

The Mississippi River source-to-sink system: Perspectives on tectonic, climatic, and anthropogenic influences, Miocene to Anthropocene

Hydrate morphology: Physical properties of sands with patchy hydrate saturation

Sediment Consolidation and Permeability at the Barbados Forearc

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