Samples from the Amazon Fan deep mass-transport deposits (MTDs) were analyzed to investigate the benthic foraminiferal assemblages. The data were compared with a detailed study of recent benthic foraminiferal contents of the Amazon shelf and slope, and with benthic foraminiferal contents of Holocene and Last Glacial Maximum (LGM) hemipelagic sediments collected in the Amazon Fan. The analyzed sediments were recovered during the Ocean Drilling Program, Leg 155. Low values for abundance and diversity were encountered in the benthic foraminiferal contents. Microfaunal differences between holes are mainly observed in rare and sparse species. Buliminids and uvigerinids, which are common on the Amazon continental slope, were found in the MTDs. Globocassidulina subglobosa and Cassidulina laevigata are common on the upper slope and were also found in the MTDs. Species like Quinqueloculina lamarckiana, Quinqueloculina cf. stalkeri, and Pseudononion atlanticum, which are present on the Amazon shelf, were also present in the MTDs. The different assemblages found in both abyssal and MTDs demonstrate their distinct origin. Dominance of buliminids suggests that the MTDs originated mostly from bathyal environments. Sparse occurrences of characteristic species indicate the continental shelf as another sediment source.

West: -49.0000 East: -46.0000 North: 7.0000 South: 4.0000

Expedition: 155

Provider: SEDIS Publication Catalogue

Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=1999-006428 (c.f. for more detailed metadata)

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