Calcareous nannofossils in Neogene sediments of ODP Leg 117 holes

Calcareous nannofossils were studied in 574 Neogene samples recovered from eight sites drilled in block-faulted basins on the continental margin of Oman. This portion of the Arabian Sea experiences seasonal upwelling associated with the southwest monsoon. Not surprisingly, some of the more typical Neogene warm-water nannoplankton are either missing entirely or are extremely rare in these sediments. Coccolithus pelagicus, a typical cold-water indicator, is extremely abundant in many samples of late Pliocene to early Pleistocene age. These intervals correspond to periods of Northern Hemisphere glaciation. Reworked Late Cretaceous and Cenozoic nannofossils are found in a majority of the samples. They were probably carried from the Arabian Peninsula or the continent of Africa on strong southwest summer winds. Ages for the various nannofossil events were calculated by projecting the nannofossil datums onto the magnetostratigraphic scale for Sites 724, 727, and 728. These are the first ages for the various nannofossil datums derived from Oman Margin sediments. The following ages have been calculated for these nannofossil events: FAD Emiliania huxleyi, 0.23 Ma; LAD Pseudoemiliania lacunosa, 0.38 Ma; FAD Helicosphaera inversa, 0.42 Ma; top of acme of Reticulofenestra sp. A, 0.70 Ma; FAD Gephyrocapsaparallela, 0.85 Ma; LAD Gephyrocapsa spp. (large), 1.07 Ma; LAD Helicosphaera sellii, 1.34 Ma; LAD Calcidiscus macintyrei, 1.47 Ma; FAD Gephyrocapsa oceanica, 1.53 Ma; FAD Gephyrocapsa caribbeanica, 1.80 Ma; LAD Discoaster brouweri, 2.03 Ma; LAD Discoasterpentaradiatus, 2.31 Ma; LAD Discoaster surculus, 2.42; LAD Discoaster tamalis, 2.77 Ma; LAD Sphenolithus abies, 3.44 Ma; and LAD Reticulofenestra pseudoumbilica, 3.44 Ma.

87Sr/86Sr ratios of middle Miocene to Pleistocene planktonic foraminifers from ODP Site 117-722 (Table 3)

Continuous magnetostratigraphy and biostratigraphy made it possible to construct a detailed late Neogene record of 87Sr/86Sr isotopic ratios of ocean water, as measured in the tests of planktonic foraminifers. Sediments recovered during Leg 117, in the western Arabian Sea, provide a continuous, high resolution sedimentary record from the early Miocene to present. The late Miocene to Recent is marked by rapidly increasing 87Sr/86Sr ratios in seawater, which results in a chronostratigraphical resolution varying from 0.2 Ma to 1.5 Ma. The 87Sr/86Sr seawater curve has a stepwise character similar to the one determined by DePaolo on Site 590B, in the Tasman Sea, and to the one determined by McKenzie on Site 653A, in the Mediterranean, confirming its use as a chronostratigraphic tool for this time span. Periods of rapid increase in the 87Sr/86Sr isotopic ratio of seawater are correlated with important changes in tectonic and climatic conditions. Experiments showed that bulk carbonate sediment samples have differing 87Sr/86Sr ratios from those of planktonic and benthic foraminifers from the same depth.

Calcareous nannofossils in Pliocene and Quaternary sediments of ODP Leg 117 holes

A total of 21 calcareous nannofossil datums was found in the upper Pliocene and Quaternary sediments recovered from the ocean floor of the North Atlantic during DSDP Leg 94. These datums were correlated to magnetostratigraphy, and ages were estimated by interpolation between magnetic reversals. Calcareous nannofossil assemblages from 549 samples recovered during ODP Leg 117 were studied in order to estimate the age of the sediments of Sites 720, 721, 722, and 731 drilled at the Indus Fan and the Owen Ridge in the Arabian Sea, Indian Ocean. We also showed that the datums above mentioned can be traced into the Indian Ocean. Two new species, namely Helicosphaera omanica and Reticulofenestra ampla, are described.

Ley 117 de 1913 (6 de diciembre) sobre tarifa de aduanas. Tarifa alfabetica, arreglada por el Ministerio de hacienda y aprobada por el Jurado de aduanas.

At head of title: Républica de Colombia.

1er. Congrès international de le̕nseignement du dessin, tenu à Paris en lH̕ôtel du cercle de la librairie, 117, Boulevard Saint-Germain, du 29 août au 1er septembre 1900.

At head of title: Exposition universelle internationale de 1900.

S. Res. 117 and S. Res. 124, prohibition of the Olympic Games in Beijing : hearing before the Committee on Commerce, Science, and Transportation, United States Senate, One Hundred Third Congress, first session, July 15, 1993.

Shipping list no.: 95-0082-P.

Overture to König Stephan, op. 117 /

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Benedictus sit Deus : für 4 Singstimmen, 2 Violinen, 2 Violen, Bass, 2 Flöten, 2 Hörner, 2 Trompeten, Pauken und Orgel ; K.117.

Ser.3, no.20 of Mozarts Sämtliche Werke. Reprint of Leipzig: Breitkopf & Härtel, 1876-1905.

2e sonate pour piano et violoncelle, op. 117

Mode of access: Internet.