Germanium - Silicon (Ge/Si) molar ratio in sea floor hot spring effluents, rivers and biogenic silica deposits

Range sea floor hot spring (11±3)e-6: rivers (0.54±0.14)e-6: biogenic silica deposits (0.66±0.12)e-6 unitless
Organism Biosphere
Reference Tréguer P et al., The silica balance in the world ocean: a reestimate. Science. 1995 Apr 21 268(5209):375-9. DOI: 10.1126/science.268.5209.375 p.377 left column bottom paragraphPubMed ID17746543
Comments P.377 left column bottom paragraph: "To resolve the various inputs of dissolved Si to the oceans, it is useful to examine germanium, an element located directly under Si in the periodic table. Sea floor hot spring effluents carry a Ge/Si molar ratio of about (11±3)x10^-6, which is much higher than that for rivers (0.54±0.14)×10^-6 and for biogenic silica deposits (0.66±0.12)×10^-6 (primary source). Assuming that biogenic silica from diatoms is the only major sink for Ge in the ocean, Mortlock et al. (primary source) constructed a mass balance for riverine and hydrothermal inputs of Ge and Si into the ocean versus biogenic deposits. Given [investigators’] estimate for riverine Si inputs, this leads to FH (hydrothermal activity) = 0.15±0.11 Tmol Si/year, which is less than 10% of that predicted from the global 3He model and from the Sr isotope balances." 1Tmol=1 teramole = 10^12 moles
Entered by Uri M
ID 114434