Ferromanganese composition

Clastic and pelagic sediments. Only a handful of clastic and pelagic samples have been analyzed for 5 Mo (Siebert et al. 2003). Clastic sediments (two samples) are indistinguishable from igneous rocks in their Mo isotope compositions. Pelagic clays (two samples) show enrichment in Mo (3.4 and 185 ppm), and also a shift toward lighter d Mo similar to ferromanganese sediments. 

Seawater. A half dozen analyses of Mo isotopes in the Pacific, Atlantic and Indian oceans, covering depths to -3000 m (Barling et al. 2001, Siebert et al. 2003), reveal two important facts. First, there is no detectable 5 Mo variation in the oceans with location or depth. Second, d Mo in the oceans is similar to the heaviest of euxinic sediments, and is heavier than in igneous rocks or ferromanganese sediments by -1.5%o and -2%o, respectively. A uniform isotopic composition in the oceans is consistent with the 10 -1 O " year ocean residence time. The explanation for the heavy isotopic composition is discussed further below. 

Guliy, V. 2004. Peculiarities of morphology and composition of ferromanganese nodules and possible mechanism of their formation. Geologist of Ukraine, 3, 61-71. 

Koschinsky, a. 2008. Ferromanganese Nodule Deposits Distribution, Composition and Origin / International Symposium Shaping the Future Deep-Sea Minerals and Mining, (March 9-12, 2008), RWTH Aachen... 

An ideal application of laser ablation MC-ICP-MS is the analysis of ferromanganese crusts from the ocean floor. The isotopic composition of Pb in the oceans should be sensitive to changes in ocean current patterns and sources. Fe-... 

PiotrowsM A. M., Lee D. C., Christensen J. N., Burton K. W., HalUday A. N., Hein J. R., and Gunther D. (2000) Changes in erosion and ocean circulation recorded in the Hf isotopic compositions of North Atlantic and Indian Ocean ferromanganese crusts. Earth Planet Sci. Lett 181(3), 315-325. 

Table 2 summarizes the average compositions of the Earth s upper crust, shale, and marine sediments, including pelagic sediments, ferromanganese nodules and crusts, metalliferous... 

Compositional data from metalliferous sediments of Deep Sea Drilling Project sites 573 (semibasal) and 574 (basal) from the central equatorial Pacific were given by Jarvis (1985). The sediments contain abundant carbonates and biogenic silica. The factor analysis results of data on a carbonate-free basis are summarized in Figures 19(a)-(d). Three samples with unusually low silica content (SiOi less than 2.7%) from site 573 were excluded. There are four distinct components FI (ferromanganese hydroxide coprecipitates Fe, Mn, Ni, Cu, Zn, V, B, P, and... 

Burns R. G. and Brown B. (1972) Nucleation and miner-alogical controls on the composition of manganese nodules. In Ferromanganese Deposits on the Ocean Floor (ed. D. R. Horn). Lamont-Doherty Geol. Observatory, New York, pp. 51-61. 

Elemental composition of freshwater and marine ferromanganese nodules... 

Chan, L.-H. and Hein, J.R., Lithium contents and isotopic compositions of ferromanganese deposits from the global ocean, Deep-Sea Res. II, 54, 1147, 2007. 

Table 11.6 Average composition of ferromanganese concretions from various basins of the Baltic Sea. Mn and Fe in per cent Co, Ni, Cu and Zn in ppm (after Glasby et al. 1997a).

Fig. 11.22 Schematic representation of deep-water flow in the world ocean based on characteristic changes in the isotopic composition of Nd, Pb and Be in ferromanganese crusts with location. The isotopic data are taken from Albarede and Goldstein (1992) and von Blanckenburg (1996a,b) (after Hein et al. 2000, Fig. 9.10).

These observations enabled Hein et al. (2000) to prepare a schematic map of deep-ocean flow in the world ocean showing the characteristic changes in the Nd, Pb and Be isotopic composition of the ferromanganese crasts along the bottom water flow path (Fig. 11.22). Particular interest in this figure lies in comparing this schematic flow path with the actual flow path of Pacific deep water based on measurements of the A C age of the deep bottom waters as presented by Schlosser et al. (2001, Plate 5.8.17 Fig. 11.23). These data confirm that the ocean bottom water flow in the Pacific is counterclockwise with the oldest waters being found in the... 

K., Conard, R. and Pisias, N., 1984. Ferromanganese nodules from MANOP Sites H, S, and R - Control of mineralogical and chemical composition by multiple accretionary processes. Geochimica et Cosmochimica Acta, 48 931-949. 

Halhach, P. and Puteanus, D., 1984. The influence of the carbonate dissolution rate on the growth and composition of Co-rich ferromanganese crusts from the central Pacific seamount areas. Earth and Planetary Science Letters, 68 73-87. 

---