Late pleistocene to holocene fluctuations in bottom-current speed in the Argentine Basin mudwave field

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Ledbetter, M. T. (1993). Late pleistocene to holocene fluctuations in bottom-current speed in the Argentine Basin mudwave field. Deep-Sea Research Part II, 40(4), 911-920.
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TitleLate pleistocene to holocene fluctuations in bottom-current speed in the Argentine Basin mudwave field
AuthorsT. Ledbetter
AbstractParticle-size analyses of core-top samples from traverses across two large asymmetrical mudwaves in the Argentine Basin were used to test a model that predicted slower bottom-current speeds on the steep, upstream (depositional) side and higher speeds on the downstream (erosional or non-depositional) side of the waveform. Consistent with the model, the silt mean particle-size of sediment on the upstream side of both mudwaves was finer than on the downstream side. Downcore analyses of the particle-size of box cores on each side of the two mudwaves were used to identify temporal trends in bottom-current speed. AMS14C dates of box core samples revealed unconformities on the downstream side of each mudwave (22-4.2 kya and 9-4 kya in cores 10 and 24, respectively). Particle sizes in samples above the unconformities were consistently coarser than those on the upstream side of each mudwave, revealing periods of high bottom-current speed from 4 to 2.5 kya. Below the unconformities the period 37 to 22 kya was characterized by high bottom-current speed in core 10 while low speeds were inferred for the period 13-9 kya in core 24. The inferred paleospeed in the cores from the depositional side of the two mudwaves reveals a trend of decreasing speed for the past 3.5 kya with short intervals of increased speed in each core.
JournalDeep-Sea Research Part II
Date1993
Start page911
End page920
ISSN09670645
Subjectsbedforms, bottom current, fluctuation, Holocene, mudwave field, palaeocurrents, Pleistocene, Quaternary, topographic effects, velocity variation, Atlantic, (South), Argentine Basin, Atlantic, Argentine Basin
NoteCited By (since 1996):8, CODEN: DSROE

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