(1) The mean value of magnetic susceptibility in Lanzhou
is 219.23×108 m3 kg1, and ranges from 36.73 to
649.5×108 m3 kg1. The magnetic characteristics are dominated
by low-coercivity magnetite. The high values of PLI
and PN and distribution of some magnetic parameters (lf,
SIRM, ARM, SOFT, ARM/SIRM, ARM/) are consistent in
industrial concentration, high-density traffic areas and areas
involving other human activities. The magnetic mineral
content and coarse magnetic particles possess certain advantages
in delineating the values of regional contamination.