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- Late Tertiary/Quaternary magnetostratigraphy and biostratigraphy of Vema Channel sediments,
- Twenty-one piston cores in a transect of the Vema Channel near 31°S were analyzed magnetostratigraphically and biostratigraphically in order to ascertain the depositional continuity in the late Tertiary and Quaternary. The cores span a depth interval of 2941-4235 m and represent three distinct physiographic provinces, each of which shows a relatively consistent accumulation pattern. The deepest cores are from the broad terraces which flank the Vema Channel axis on both the west (∼3650 mm) and east (4150-4250 m); these cores show the highest accumulation rates in the region (>20 m m.y.-2) and no evidence of unconformities. Twelve cores from the flanks of the Rio Grande Rise (2941-3950 m) show depositional continuity in the late Quaternary and normal pelagic accumulation rates (5-10 m m.y.-2), with evidence in two of the cores for minor erosional hiatuses on a local scale, perhaps due to slumping. A relatively narrow transition zone between the Rio Grande Rise flanks and the eastern terrace (3950-4150 m) shows buried manganese pavements and near-outcrops of Miocene/Pliocene strata, indicating intermittent erosion during the late Tertiary and Quaternary, perhaps due to episodes of intensified AABW flow. Modern flow within this transition zone and over the eastern terrace is relatively weak ( \ ̄gu ≈ 2 cm s-2) and southward. The presence of well-developed sediment waves on the terrace and buried erosional unconformities upslope to the east suggests substantially higher current velocities during the late Tertiary than those present today., Cited By (since 1996):2, CODEN: MAGEA, ,
- Johnson, Ledbetter, Tappa, Thunell
- Morphological, molecular, and in situ behavioral observations of the rare deep-sea anglerfish Chaunacops coloratus (Garman, 1899), order Lophiiformes, in the eastern North Pacific
- In situ observations and collections of Chaunacops coloratus (Garman, 1899) from seamounts in the eastern North Pacific Ocean lend new behavioral, morphological and molecular data to an under-sampled, deep-sea group of fishes in the order Lophiiformes. Seven observations were made at Davidson Seamount, 130. km southwest of Monterey, CA, and from the Taney Seamount chain, 290. km west of Moss Landing, CA, from depths ranging from 2313 to 3297. m. Specimens were collected at both locations. Morphometric and meristic analyses were performed to identify individuals to the species level. These observations of C. coloratus provide greater latitude and depth distributions in the eastern North Pacific Ocean than previously known. Detailed habitat information indicated the fish occurred near manganese-encrusted volcanic talus slopes, a highly rugose habitat. Video observations revealed possible ontogenetic color changes in which small fish were blue and large fish were red. Video recorded rapid, vertical swimming as an escape response and maneuvering, or walking, with pectoral and pelvic fins and esca deployment. Phylogenetic analyses used here verify what has been known since Garman first described C. coloratus in 1899, that Chaunax and Chaunacops are closely related; molecular tools complement previous knowledge and genetic information created has been submitted to GenBank for further use by the scientific community. © 2012 Elsevier Ltd.
- Lundsten, Johnson, Cailliet, DeVogelaere, Clague