Evidence of late glacial runoff in the lower Mississippi Valley

Saucier, Roger T.

doi:10.1016/0277-3791(94)90011-6

Cited by 54 publications

(24 citation statements)

References 4 publications

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“…The marks of catastrophic flood outbursts in the form of deeply cut spillways, linking an extensive network of midcontinent proglacial lakes and feeding directly into the Mississippi River, have been recognized in a number of studies of the early deglaciation continental records [ Kehew and Lord , 1987; Saucier , 1994; Knox , 1996]. However, the duration and exact timing of each outburst are uncertain because of overprinting of the overflow channels and changes in their depth of flow [ Licciardi et al , 1999], and therefore correlation between the continental and marine records of floods is tenuous.…”

Section: Discussionmentioning

confidence: 99%

Meltwater flooding events in the Gulf of Mexico revisited: Implications for rapid climate changes during the last deglaciation

Aharon

2003

Paleoceanography

128

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North American freshwater runoff records have been used to support the case that climate flickers were caused by shutdowns of the ocean thermohaline circulation (THC) resulting from reversals of meltwater discharges. Inconsistencies in the documentation of these meltwater switches, however, continue to fuel the debate on the cause/s of the oscillatory nature of the deglacial climate. New oxygen and carbon isotope records from the northern Gulf of Mexico depict in exceptional detail the succession of meltwater floods and pauses through the southern routing during the interval 16 to 8.9 ka (14C years BP; ka, kiloannum). The records underscore the bimodal role played by the Gulf of Mexico as a destination of meltwater discharges from the receding Laurentide Ice Sheet. The evidence indicates that the Gulf of Mexico acted as the principal source of superfloods at 13.4, 12.6, and 11.9 ka that reached the North Atlantic and contributed significantly to density stratification, disruption of ocean ventilation, and cold reversals. Gulf of Mexico lapsed into a “relief valve” position in post‐Younger Dryas time, when meltwater discharges were rerouted south at 9.9, 9.7, 9.4, and 9.1 ka, thus temporarily interrupting North Atlantic‐bound freshwater discharges from Lake Agassiz. The history of meltwater events in the Gulf of Mexico contradicts the model that meltwater flow via the eastern outlets into the North Atlantic disrupted the ocean THC, causing cooling, while diversions to the Gulf of Mexico via the Mississippi River enhanced THC and warming.

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Section: Discussionmentioning

confidence: 99%

Meltwater flooding events in the Gulf of Mexico revisited: Implications for rapid climate changes during the last deglaciation

Aharon

2003

Paleoceanography

128

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“…These braided deposits were transported by huge flood pulses, the largest of which (melt water flood, labeled MWF-4 in Table 4) is estimated by Aharon (2003) to have had an average discharge rate ~2.3 times the record discharge rate of the 2011 Mississippi Flood, with a duration of ~1,000 years (Table 4). These floods undoubtedly helped incise and broaden the deep (20-30 m below shelf) and wide (~100 km) incised valley (Autin, 1991;Saucier, 1994b;Kulp et al, 2002). This valley experienced marine inundation earlier than the more elevated adjacent continental shelves, with the oldest dated marine transgressive deposits formed ca.…”

Section: Glaciation and Deglaciation And Associated Phenomena Left A mentioning

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

148

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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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“…Over the Holocene, the Mississippi River (M.R.) delta has experienced semi‐periodic avulsions, or the rapid abandonment of a channel course for a new course through the delta (Blum & Roberts, 2012; Fisk, 1952; Saucier, 1994). The Atchafalaya River (A.R.)…”

Section: Introductionmentioning

confidence: 99%

Influences on Discharge Partitioning on a Large River Delta: Case Study of the Mississippi‐Atchafalaya Diversion, 1926–1950

Shaw

Mason

et al. 2021

Water Resources Research

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Evidence of late glacial runoff in the lower Mississippi Valley

Cited by 54 publications

References 4 publications

Meltwater flooding events in the Gulf of Mexico revisited: Implications for rapid climate changes during the last deglaciation

Meltwater flooding events in the Gulf of Mexico revisited: Implications for rapid climate changes during the last deglaciation

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

Influences on Discharge Partitioning on a Large River Delta: Case Study of the Mississippi‐Atchafalaya Diversion, 1926–1950

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