Pacific Ocean sediment

Fig. 14-6 Profiles of potential temperature and phosphate at 21 29 N, 122 15 W in the Pacific Ocean and a schematic representation of the oceanic processes controlling the P distribution. The dominant processes shown are (1) upwelling of nutrient-rich waters, (2) biological productivity and the sinking of biogenic particles, (3) regeneration of P by the decomposition of organic matter within the water column and surface sediments, (4) decomposition of particles below the main thermocline, (5) slow exchange between surface and deep waters, and (6) incorporation of P into the bottom sediments.

Figure 1.159. Eu/Eu values of (A) modern sediment, hydrothermal solution and seawater and (B) mid-Miocene to early Pliocene Japan Sea see in text). Modern data are from the Pacific ocean,...

Marcantonio F, Anderson RF, Higgins S, Stute M, Schlosser P, Kubik PW (2001b) Sediment focusing in the central equatorial Pacific Ocean. Paleoceanography 16(3) 260-267 Marcantonio F, Kumar N, Stute M, Anderson RF, Seidl MA, Schlosser P, Mix A (1995) A comparative study of accumulation rates derived by He and Th isotope analysis of marine sediments. Earth Planet. Sci. Letters 133 549-555... 

Lee [2] using a hydride generation atomic absorption spectrometric method has investigated the bioaccumulation of bismuth on marine sediment samples collected in Narragensett Bay and the North Pacific Ocean. 

The matrices and sources of the sediments listed in Table 4.2 are sometimes unclear. Those that are known are highly weighted toward clastic (quartz- and aluminosilicate-rich) marine sediments from coastal environments. Some of these reference materials, such as MESS-3 (NRC-Canada), MAG-1 (USGS) and the Arabian Sea and Pacific Ocean samples (IAEA 315, and 368), could provide excellent examples of clastic marine sediment representing the main repositories of organic matter in the ocean (Hedges and Keil, 1995). The listed materials fail to include both open-ocean opal and carbonate oozes, as well as pelagic red clays. 

Calvert SE, Price NB (1977) Geochemical variation in ferromanganese nodules and associated sediments from the Pacific Ocean. Mar Geochem 5 43-47... 

Mid-depth maxima are produced by mid-depth sources of metals. Some of these maxima are created by remineralization of detrital biogenic particles, such as seen in Figure 11.4f for cadmium. Others are caused by lateral transport of metals mobilized from coastal sediments as illustrated in Figure 11.17(a) for manganese. Mid-depth maxima can also result from hydrothermal emissions as shown in Figure 11.19 for Mn (aq) and He(g) at a site in the Eastern North Pacific Ocean. Hydrothermal fluids are emitted into the ocean from chimneys located atop the East Pacific Rise at water depths of about 2500 m. After entering the ocean, the Mn and He are entrained in subsurfece currents and... 

The sediment oxygen penetration depth as a function of water coiumn depth in the Atlantic Ocean (open symbols) and Pacific Ocean (closed symbols). Source-. From Martin, W. R., and F. L. Sayles (2003). Treatise on Geochemistry, Elsevier. 

Parameters influencing the distribution of calcium carbonate with increasing water depth in equatorial Pacific sediment. Note that fi is reported as a percentage (%). Source From van Andel, Tj. H., et al. (1975). Cenozoic History and Paleoceanography of the Central Equatorial Pacific Ocean, Geological Society of America, Boulder, CO, p. 40. 

The slowest growth rates are found in the Fe-Mn oxides that have formed predominantly by precipitation of solutes from seawater, being on the order of 1 to a few millimeters per million years. Because of slow formation rates, these hydrogenous precipitates tend to form only in areas where sedimentation rates are slow, such as the abyssal plains of the mid-Pacific Ocean, or where bottom currents are strong enough to prevent sediment accumulation, such as on submarine seamounts and plateaus. 

The distribution of sediment types in the Pacific Ocean is much different from that of the Atlantic. Except for the coastline of the northwest United States, the Pacific is ringed by deep-sea trenches and, hence, has relatively narrow continental shelves. The trenches effectively trap all the terrigenous particles carried to the sea by river runoff. The Pacific Ocean is much wider than the other oceans thus the flux of wind-borne lithogenous particles is spread over a much greater area and produces a much lower mass flux, on an areal basis, to the seafloor. This makes other particles relatively important in determining the composition of the sediments in the Pacific ocean. 

Relative primary productivity, POC fluxes at 105 and 3000 m, and POC sediment accumulation rates versus latitude in the central equatorial Pacific Ocean. Data are normalized to the maximum value in each transect. Survey 1 was conducted during February-March 1992 under El Nino conditions and Survey 2 from August to September 1992 under non-El Nino conditions at longitudes ranging from 135 to 140°W. Ordinate scale is reset to 1.0 at each maximum, and the absolute magnitude (mmolCm ij-i) of each parameter is given next to its maximum. Source-. From Flernes, P. J., et al. (2001). Deep-Sea Research I 48, 1999-2023. 

Rushdi Al, Simoneit BRT, Hydrothermal alteration of organic matter in sediments of the Northeastern Pacific Ocean Part 1. Middle Valley, Juan de Fuca Ridge, Appl Geochem 17 1401—1428, 2002. 

CARROLL (D.), 1969. Chlorite in central north Pacific ocean sediments. 

HEATH (G.R.), 1969. Mineralogy of Cenezoic deep-sea sediments from the equatorial Pacific Ocean. Bull. Geol. Soc. Arne. JO, 1997-2018. 

---