- acid
- aggregate
- anthropogenic
- arsenic
- base
- basement
- decomposition
- drainage
- forest
- greywacke
- impurities
- mercury
- mineralised
- natural
- neutralisation
- northland
- ppm
- release
- roads
- roots
- runoff
- sediment
- soil
- soils
- solid
- spring
- strongly
- subordinate
- subtropical
- sulfides
- system
- temperate
- theoretical
- typically
- underlying
- unmineralised
- valid
- warm
- washed
- weathered
- weathering
- yields
