Lithogenic

H. L. Windom, "Lithogenous Matedal in Marine Sediments," Chemical Oceanography, Academic Press, Inc., New York, 1976. 

Yu E-F, Francois R, Bacon M (1996) Similar rates of modem and last-glacial ocean thermohaline circulation inferred from radiochemical data. Nature 379 689-694 Zheng Y, Anderson RF, van Geen A, Fleisher MQ (2002) Preservation of particulate non-lithogenic uranium in marine sediments. Geochim Cosmochim Acta 66(17) 3085-3092. 

Measured concentrations of Th and Pa in marine sediments consist of three components that scavenged from seawater that supported by U contained within lithogenic minerals and that produced by radioactive decay of authigenic U. Most of the proxies described in this paper make use of only the scavenged component. Measured °Th and Pa must therefore first be corrected for the presence of the other two... 

Where all nuclide measurements are expressed in activities. In both expressions, the first term in curly brackets corrects for Th (or Pa) supported by U in lithogenic material, and the second term in curly brackets corrects for °Th (or Pa) ingrown from authigenic U. For samples that are known to be young, such as sediment trap or core-top samples, t = 0 and this second term equals zero reflecting the lack of time for decay of authigenic U in such samples. 

Lithogenic eolian deposition is a primary chemical contributor to TV snow (Lyons et a ., 2003 Williamson et al., 2007 ... 

Trautwein, E. A., Siddiqui, A., and Hayes, K. C. (1993). Modeling plasma lipoprotein-bile lipid relationships Differential impact of psyllium and cholestyramine in hamsters fed a lithogenic diet. Metabolism 42,1531-1540. 

As shown in Table 13.6, the sedimentation rate of the clay nfineral fraction of pelagic deposits is very slow, being on the order of millimeters per thousand years. Spatial variations reflect geographic variability in the supply rate of these lithogenous particles. This is generally related to distance from land, causing the South Pacific to have sedimentation rates less than 1 mm per thousand years. 

Coral reefs and mangrove swamps Modern lithogenous sediment Relict sediment (continental shelf)... 

The abyssal clays are composed primarily of clay-sized clay minerals, quartz, and feldspar transported to the siuface ocean by aeolian transport. Since the winds that pick up these terrigenous particles travel in latitudinal bands (i.e., the Trades, Westerlies, and Polar Easterlies), the clays can be transported out over the ocean. When the winds weaken, the particles fell to the sea siufece and eventually settle to the seafloor. Since the particles are small, they can take thousands of years to reach the seafloor. A minor fraction of the abyssal clays are of riverine origin, carried seaward by geostrophic currents. Despite slow sedimentation rates (millimeters per thousand years), clay minerals, feldspar, and quartz are the dominant particles composing the surface sediments of the abyssal plains that lie below the CCD. Since a sediment must contain at least 70% by mass lithogenous particles to be classified as an abyssal clay, lithogenous particles can still be the major particle type in a biogenous ooze. 

The dominant clay mineral at high latitudes is chlorite. In addition to ice rafting, lithogenous materials are transported in the polar oceans by rivers and winds. Polar seas are also characterized by diatomaceous oozes due to the occurrence of upwelling supported by divergence at 60°N and 60°S. 

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. 

Because of the relative scarcity of lithogenous particles and fast seafloor spreading rates, metalliferous sediments are common around the East Pacific Rise and very high densities of manganese nodules are present on the abyssal plains, especially in the Southern Hemisphere. In these locations, the weathering products of volcanic detritus, such as montmorillonite, phillipsite, nontronite, and celadonite, are also found in great abimdance. 

The continental shelves cover most of the seafloor in the Arctic Ocean, making this the shallowest ocean. Thus, most of the sediments are neritic. Because of light limitation, primary production is inhibited, so river runoff and ice rafting supply most of the particles to this ocean. As a result, lithogenous and glacial marine sediments are most common. 

Two different pathways of formation are possible (Stanjek, 2000). One route involves aerial oxidation of lithogenic magnetite as suggested for Brazilian Oxisols on basic igneous rocks. The mechanism of this topotactic reaction is described in Chapter 14. These maghemites are usually titaniferous as are the magnetites from which they are derived (see Chap. 15) and almost free from or very low in Al (Allan et al., 1989). Their unit cell size is a function of the residual Fe" and the Ti content. 

Tritapepe R, Di Padova C, Zuin M, Bellomi M, Podda M. Lithogenic bile after conjugated estrogen. N Engl J Med 1976 295(17) 961-2. 

---