(Table T1) Radiolaria abundance of ODP Hole 175-1082A, supplement to: Weinheimer, Amy L (2001): Radiolarians from Northern Cape Basin, Site 1082. In: Wefer, G; Berger, WH; Richter, C (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 175, 1-16

• Main Author: Weinheimer, Amy L
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2001
• Subjects: Sample code/label; Radiolarians abundance; Radiolarian preservation; Spongodiscid sp.; Dictyocoryne profunda; Tetrapyle octacantha; Botryostrobus auritus/australis group; Spongurus cf. elliptica; Dictyocoryne sp.; Carpocanarium papillosum; Cornutella profunda; Spongopyle osculosa; Corocalyptra columba; Lamprocyrtis hannai; Larcopyle buetschlii; Lithelius minor; Dictyophimus gracilipes; Acrosphaera murrayana; Pterocanium trilobum; Eucyrtidium acuminatum; Helotholus histricosa; Lamprocyclas maritalis; Spongocore puella; Phormostichoartus corbula; Cycladophora davisiana; Dictyophimus crisiae; Pterocorys minythorax; Spongotrochus venustum; Anthocyrtidium zanguebaricum; Lampromitra quadricuspis; Pterocanium praetextum eucolpum; Pterocanium sp.; Pterocorys zancleus; Carpocanistrum sp.; Didymocyrtis tetrathalamus; Spongurus pylomaticus; Stylodictya aculeata; Spongaster tetras tetras; Theocalyptra bicornis; Lithomelissa setosa; Peripyramis circumtexta; Spongotrochus glacialis; Clathrocyclas bicornis; Lipmanella dictyoceras; Botryostrobus aquilonaris; Lithostrobus hexagonalis; Dictyophimus infabricatus; Theocorythium trachelium; Anthocyrtidium ophirense; Lamprocyrtis nigriniae; Lophospyris spp.; Amphirhopalum ypsilon; Lampromitra coronata; Arachnocorys circumtexta; Cycladophora davisiana cornutoides; Eucyrtidium cf. teuscheri; Hexacontium enthacanthum; Pterocanium praetextum praetextum; Actinomma cf. leptodermum; Lophospyris pentagona pentagona; Phormospyris stabilis stabilis; Arachnocorys penthacantha; Botryocyrtis scutum; Cyrtolagena laguncula; Rhizoplegma boreale; Radiolarians; Drilling/drill rig; DSDP/ODP/IODP sample designation; Counting, radiolarians; Leg175; Joides Resolution; Ocean Drilling Program ODP; Antarctic; Pillar; Southern Ocean; Antarc*
• Online Access: https://dx.doi.org/10.1594/pangaea.787554; https://doi.pangaea.de/10.1594/PANGAEA.787554

A primary objective of Leg 175 was to investigate the upwelling history of the Benguela Current. Upwelling along the coast is found over the shelf in several well-established cells, as well as along the shelf-slope break, and extends over the 1000-m isobath. Streaming filaments along the coast also carry upwelled water off shore (Shannon, 1985). The upwelled nutrient-rich waters are sourced from the South Atlantic central water mass, which is a mixture of subtropical and subantarctic water masses. Below the central water mass lies Antarctic intermediate water (Shannon and Hunter, 1988, doi:10.2989/025776188784480735; Stramma and Peterson, 1989, doi:10.1175/1520-0485(1989)019<1440:GTITBC>2.0.CO;2).The upwelling system supports a robust marine community (Shannon and Pillar, 1986) where radiolarians are abundant (Bishop et al., 1978, doi:10.1016/0146-6291(78)90010-3). The endemic nature of radiolarians makes them useful in reconstructing the paleocirculation patterns. The biogeographic distribution of many species is limited by water-mass distribution. In a given geographic region, species may also have discrete depth habitats. However, their depth of occurrence can change worldwide because the depths of water masses vary with latitude (Boltovskoy, 1999). Consequently, species found at shallow depths at high latitudes (cold-water fauna) are observed deeper in the water column at lower latitudes. The low-latitude submergence of cold-water species broadens their distribution, resulting in species distributions that can cover multiple geographic regions (Kling, 1976, doi:10.1016/0011-7471(76)90880-9; Casey, doi:10.1016/0031-0182(89)90017-5; 1971; Boltovskoy, 1987, doi:10.1016/0377-8398(87)90014-4). Since radiolarian distribution is closely related to water-mass distribution and controlled by climatic conditions rather than geographic regions, similar assemblages characterize the equatorial, subtropical, transition, subpolar, and polar regions of ocean basins (Petrushevskaya, 1971a; Casey, 1989, doi:10.1016/0031-0182(89)90017-5; Boltovskoy, 1999). Numerous radiolarian species found in water masses in the Angola and Benguela Current systems have also been observed in plankton net samples, sediment traps, and surface-sediment studies in the Atlantic sector of the Southern Ocean, where they exhibited particular water-mass affinities (Abelmann, 1992a, doi:10.1007/BF00243107; Abelmann 1992b, doi:10.1007/BF00243108; Abelmann and Gowing, 1997, doi:10.1016/S0377-8398(96)00021-7). This report presents data on the radiolarian fauna recovered from Site 1082 sediments in the form of a survey of species reflecting the latitudinal migration of the Angola-Benguela Front and upwelling. The data constitute a time series of relative radiolarian abundances at very high resolution (every 20 cm) of the upper 12 m of Hole 1082A. : Only radiolaria skeletons of the >45 µm fraction were counted (at 100x). Selected species were counted along 1-3 transects until a total of 300 specimens were counted.