Aluminum migration and chemical weathering in subalpine and alpine soils and tills, Mt. Moosilauke, New Hampshire: the effects of acid rain
Aluminum mobilization in response to acidification by precipitation has been described by three methods: (1) observation of existing and relict soil weathering products, particularly clay minerals, (2) measurement of soil solution and low-order stream chemistry, and (3) quantification of the distribution, amount, and dissolution rate of labile soil aluminum. From the latter two methods, the amount and rate of aluminum leaching is predicted. Six labile aluminum reservoirs are, in order of decreasing solubility: (1) inorganic and organic exchangeable aluminum, (2) organo-aluminum complexes, (3) amorphous aluminum trihydroxide, (4) hydroxy-aluminum interlayers in vermiculitic clay minerals, (5) clay mineral lattices and (6) primary aluminosilicates. Progressive acid dissolution (P.A.D.) analysis reveals that only the first four reservoirs yield significant amounts of soluble aluminum and have kinetically distinct solubilities. The relative abundance of the different Al reservoirs depends on exposure, slope, drainage, and depth in the profile. From soil solution data and P.A.D. studies, yearly aluminum losses from soil reservoirs are calculated. At present rainfall acidity levels, the best estimates of the lifespan of these soil aluminum-pH buffers fall between 170 and 840 years. The rate of depletion of soil aluminum is orders of magnitude greater than the rate at which bedrock weathering can replace it.
- OSTI ID:
- 5608169
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ACID RAIN
CHEMICAL REACTION KINETICS
ENVIRONMENTAL EFFECTS
ALUMINIUM
ENVIRONMENTAL TRANSPORT
LEACHING
SOILS
WEATHERING
NEW HAMPSHIRE
ATMOSPHERIC PRECIPITATIONS
DISSOLUTION
ELEMENTS
FEDERAL REGION I
KINETICS
MASS TRANSFER
METALS
NORTH AMERICA
RAIN
REACTION KINETICS
SEPARATION PROCESSES
USA
510100* - Environment
Terrestrial- Basic Studies- (-1989)