Abstract:

Mineral magnetic parameters and contents of SiO₂（w(SiO₂)） were measured on sediments of upper reaches of Haohe River and quartz tail-sands. Results show that w(SiO₂) of the sediments is more than 80%. It proves that sediments of upper reaches of Haohe River has been seriously polluted by quartz tail-sands. Magnetic measurement results show that the magnetic characteristics for sediments and quartz tailsands are basically the same. The main magnetic mineral of the two kinds of samples is ferrimagnetic magnetite, and the content of magnetic mineral is low. The magnetic grains of the two kinds of samples are wide, mainly in the 0.1-5 μm region. When a lot of the quartz tail-sands is rushed into Haohe River, its effect weakens the magnetism of sediments, while the magnetic grains become bigger. The w(SiO₂) of sediments and the magnetic parameters(χ, SIRM and χ_ARM) have negative correlation(-0.83≤R≤-0.61). It shows that the magnetic parameters might reflect degree of sediment’s pollution by quartz tail-sands. The lower the scale of the magnetic parameters, the more seriously sediment will be polluted by quartz tail-sands.

Key words: quartz tail-sands, Haohe River, sediments, environmental magnetism, pollution