Continental margins

Gas hydrates are an ice-like material which is constituted of methane molecules encaged in a cluster of water molecules and held together by hydrogen bonds. This material occurs in large underground deposits found beneath the ocean floor on continental margins and in places north of the arctic circle such as Siberia. It is estimated that gas hydrate deposits contain twice as much carbon as all other fossil fuels on earth. This source, if proven feasible for recovery, could be a future energy as well as chemical source for petrochemicals. 

Why do continental margins play a dominant role on the biogeochemical cycling of elements ... 

Sloss, L. L. and Speed, R. C. (1974). Relationships of cratonic and continental-margin tectonic episodes. In "Tectonics and Sedimentation" (W. R. Dickenson, ed.), pp. 98-119. Society of Economic Paleontologists and Mineralogists, Tulsa, Oklahoma, SEPM Special Publication 22. 

Anschutz, P., Zihong, S., Sundby, B., Mucci, A., and Gobeil, C. (1998). Burial efficiency of phosphorus and the geochemistry of iron in continental margin sediments. Limnol. Oceanogr. 43,53-64. 

Ruttenberg, K. C. and Berner, R. A. (1993). Authigenic apatite formation and burial in sediments from non-upwelling, continental margin environments. Geochim. Cosmochim. Acta 57,991-1007. 

Miller, K.G., Fairbanks, R.G. and Mountain, G.S. (1987) Tertiary oxygen isotope synthesis, sea level history, and continental margin erosion. Paleoceanography, 2, 1-19. 

Heussner S, Cherry RD, Heyraud M (1990) Po-210 and Pb-210 in sediment trap particles on a Mediterranean continental margin. Cont. Shelf Res 10 989-100 Heyraud M, Cherry RD (1983) Correlation of Po-210 and Pb-210 enrichments in the sea-surface microlayer with neuston biomass. Cont Shelf Res 1 283-293 Honeyman BD, Santschi PH (1989)The role of particles and colloids in the transport of radionuclides and trace metals in the oceans. In Environmental particles. Buffle J, van Leewen HP (eds) Lewis Publishers, Boca Raton, p 379-423... 

Radakovitch O, Cherry RD, Heussner S (1999) Particulate fluxes on the Rhone continental margin (NW Mediterranean). Part III °Po and 4 b data and the particle transfer scenario. Deep-Sea Res I 46 1539-1563... 

Other applications of °Thxs profiling to assess accumulation rates of sedimentary components include carbonate accumulation in the Western Equatorial Atlantic (Rtihlemann et al. 1996) biogenic and terriginous particle accumulation on the Australian continental margin (Veeh et al. 2000) sedimentation rates in the North East Atlantic (McManus et al. 1998 Thomson et al. 1993 ) (Fig. 5) sedimentation rates during key... 

Figure 8. Partition coefficients (Kd) for Th and Pa and the fractionation factor (F) between Th and Pa plotted as a function of the opal and calcium carbonate percentage in settling particulate material. Note the tendency for the Kd for Th to increase with increasing carbonate fraction and decrease with increasing opal fraction. Pa shows the opposite behavior so that F increases with low opal fraction or high carbonate fraction. This plot is modified from Chase et al. (in press-b) but excludes the continental margin data also shown in that study and instead focuses exclusively on open-ocean sites.

Nelson CH (1990) Post Messinian deposition rates and estimated river loads in the Ebro sedimentary system. In Nelson CH, Maldonado A (eds) Marine geology of the Ebro continental margin. Geology 95 395 -18... 

Figure 1 presents the model. Precipitation rates are 9000 km3 between atmosphere and continental interior (Cl), 110000 km3 between atmosphere and continental margins (CM), and 458000 km3 between atmosphere and oceans. Mean DIC for global precipitation is 81.59 (xmol/l. Thus, the atmospheric C02 sink is 0.0044, 0.054, and 0.22 Pg C/a, respectively (Fig. 1). Annual global Cl RO and CM RO are 2000 and 44800 km3, respectively (Baumgartner Reichel 1975 Shiklomanov 1993). Using global mean soil pC02 of 6393 ppmv and global mean surface temperature of 15°C, the equilibrium values of DIC are 300 and 3640 amol/l for the non-carbonate and carbonate terranes, respectively. Thus, C02 sinks by Cl and CM RO are 0.013 and 0.28 Pg C/a, respectively.

Ransom et al. (1995) and Godon et al. (2004) present 8 Cl results for a variety of marine sedimentary pore fluids taken from the northeast African passive continental margin to pore fluids from the Nankai and Caribbean convergent margins. The measurement of these marine... 

Thamdrup B, Canfield DE (1996) Pathways of carbon oxidation in continental margin sediments off central Chile. Limnol Oceanogr 41 1629-1650... 

Since the continental margins are relatively small compared to the total surface area of the ocean, the surface areas of the two reservoirs are also considered to be equal in size. From this perspective, the global rate of water transport between the boxes can be expressed as the annual exchange of a water layer that is 300 cm thick. This... 

Table 12.3 Electron Acceptors in (a) Pelagic Sediments and (b) Continental Margin Sediments. ... 

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