Marine and lacustrine sediments

Hites, R.A. and P.M. Gschwend. 1982. The ultimate fates of polycyclic aromatic hydrocarbons in marine and lacustrine sediments. Pages 357-365 in M. Cooke, A.J. Dennis, and F.L. Fisher (eds.). Polynuclear Aromatic Hydrocarbons Physical and Biological Chemistry. Battelle Press, Columbus, OH. 

Gschwend, P. M., and R. A. Hites, Fluxes of polycyclic aromatic hydrocarbons to marine and lacustrine sediments in the Northeastern United States , Geochim. Cosmochim. Acta, 45,2359-2367 (1981). 

Wang, X.C., and Lee, C. (1990) The distribution and adsorption behavior of aliphatic amines in marine and lacustrine sediments. Geochim. Cosmochim. Acta 54, 2759-2774. 

Kaland, P. E., Krzywinski, K., Stabell, B., 1984. Radiocarbon-dating of transitions between marine and lacustrine sediments and their relation to the development of lakes. Boreas, 13, 243-258. 

Pore waters in oxic zones are characterized by a dissolved oxygen content greater than 0.5 ml/1. Oxic carbonates prevail in (i) subaerial environments, such as the vadose zone where the pores are periodically filled with gas, air and/or water (ii) immediately below the sediment-water interface in aquatic environments and (iii) in the phreatic zone below the water table where all the pores are regularly filled with water. The thickness of the oxic zone depends on the penetration, by diffusion or advection, of oxygen below the sediment surface. Oxygen diffusion into pore waters is largely controlled by the organic content and the rate of deposition. In marine and lacustrine sediments the... 

Thus, explanation of the ice-core records demands a creative interaction with other fields of earth system science. We identify two such fields as crucial. The first is global modeling, which is a standard approach to climate change problems (both present / future and past) and is being actively extended to include interactions of the biogeochemical cycles with climate. The second is Quaternary science in the broad sense, especially insofar as Quaternary paleo-environmental records have been standardized and compiled on a global scale. Quaternary scientists have amassed data from widely distributed natural archives such as marine and lacustrine sediments which, when suitably compiled, yield spatially extensive information about many aspects of climate, ecosystem composition, and even some indicators of atmospheric composition such as the... 

Carman, R., Ediund, G. and Damberg, C. (2000) Distribution of organic and inorganic phosphorus compounds in marine and lacustrine sediments a P NMR study. Chemical Geology 163, 101-114. 

In marine and lacustrine muds, the initial sulfide phase precipitated during early diagenesis is mackinawite (FeS09) which is subsequently converted to greigite (Fe3S4) and pyrite (FeS2) (85-89). This reaction path leads to the formation of framboidal pyrite (88.90). However, in salt marsh sediments under low pH and low sulfide ion activity conditions, direct precipitation of pyrite by reaction of ferrous iron with elemental sulfur without the formation of iron monosulfides as intermediates has been reported (85-87.89.91.92). This reaction is one possible pathway for the precipitation of pyrite as single crystals (89). 

Figure 1. Framework for main environments examined in studies of sulfur in recent sediments. Freshwater peats, marine peats, marine sediments, and lacustrine sediments occupy comers A, B, C, and D, respectively. Sediments in this study range from A to D and a large proportion are in region I.

Marine and lake sediment, the marine sediments were collected by a stainless steel grab from a boat or a ship. The lacustrine sediments were collected on the lake shore with a polypropylene scoop. The samples collected were manually pre-homo-genised and transferred into 1 1 polycarbonated cylindrical jars. The jars were wrapped in double polyethylene bags and immediately stored at -30°C. 

Algal indicators. Individual marker compounds indicative of sediment contributions from algae (Figure 2) may occur in both marine and lacustrine environments, although their... 

Hydrothermal and mantle contributions of methane are not significant. Oceanic surface waters are oversaturated with respect to methane, due to bacterial (methanogenic) activity in localized anaerobic environments, such as the digestive tracts of zooplankton, resulting in a net flux of methane to the air. Methane is similarly produced in freshwater environments. Deep ocean waters contain much lower methane concentrations than surface waters and the methane generated within anaerobic sediments is mostly oxidized by methanotrophes. Marine and lacustrine environments as a whole do not make a large contribution to the methane flux, but natural wetlands do. The bacterial... 

Fig. 19.33 The core recovered from the deepest part of Lake Vanda (Site 4A) by the Dry Valley Drilling Project in November 1973 consists of granitic basement overlain by marine glacial, and lacustrine sediment in about 68.25 m of water. B = basement, M = marine, G = glacial, L = lacustrine, W = water (Data from Cartwright et al. 1974) (See also Gumbley et al. 1974)...

Sedimentary evidence for tsunamis is found along the shorelines of marine and lacustrine environments. The shorelines of the Earth vary from place to place and can be simplified into two characteristic environments flat sandy coasts or marshes and cliffed rocky coasts (Fig. 3a, b). The formation of a coast with sediments at the seashore depends on several parameters including the position of the sea level, the tidal influence, and the presence of river inlets (e.g., sculpted into bays, cuspate forelands with mudflats, marshes, sandy beaches, or dunes). The geomorphology of a coast plays a major role in preserving tsunamigenic deposits. 

The amount of reduced sulfur in freshwater lacustrine sediment and in most marine sediment is a function of the availability of the limiting reactant during sulfate reduction—whether sulfate or organic matter. This simple two end-member model must frequently be modified for saline lacustrine sediment and for some marine sediment in order to reflect the capacity of the... 

Total sulfur concentrations in freshwater lacustrine sediments described in these studies may reach about 1 % (8), but are generally less than 0.4%. Marine sediments in California generally have average total sulfur concentrations of less than 1%, but are usually greater than 0.6% (6). Values for pyritic sulfur of 0.31 to 1.98% are given for coastal and marine sediments of Long Island Sound (7). 

---