the atmosphere and driven to the surface by barometric pumping
(Cameron et al., 2004), or be released from the oxidation of sulfide in
ore deposits, or from mantle degassing (Gold and Soter, 1980); 4) sedimentary
or volcanic rocks and overlying regolith with fractures or pores
allow gases and gas-like nanoparticles to migrate upward through
covers to the surface; 5) arriving at the surface, some nano-particles
may be retained in soil pore gases, and some trapped by soil minerals
such as Fe and Mn oxides, clay minerals, colloids, soluble salts and secondary
carbonates, and organic matters; and 6) lateral dispersion has
been taking place under the surface process of peneplanation