Origin of organism-dependent biogenic silica quartz formation.
Organism-dependent biogenic quartz formation in the steady-state environment is a phenomenon that can address the global environmental issues such as diagenetic evolution, biogeochemical cycling, and reservoir formation, but detailed studies have not been performed so far. Here, steady-state quartz formation is studied for amorphous silica of different biogenic origin on the basis of the recently established mechanistic model [Sato et al., J. Phys. Chem. C 2011, 115, 18131]. Amorphous silica originated from rice husks possesses angstrom-scale pores larger by 1.3 Å than those originated from diatom algae. The slight difference of pore size dramatically reduces activation energies of water diffusion by 78% and reactions of water molecules at pore surfaces by 47%, resulting in the reduction of activation energy of biogenic quartz formation by 64%. The present findings evidence that angstrom-scale pores intrinsically residing in the amorphous matrix are the organism-dependent origin of steady-state biogenic quartz formation.
Department of Environmental Sciences, Tokyo Gakugei University, Tokyo, Japan. sato-k@u-gakugei.ac.jp
Kiminori
K
Sato
D017377:Diatoms / Q000378:metabolism; D004058:Diffusion; D011791:Quartz / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D014867:Water; D011791:Quartz; D012822:Silicon Dioxide