INVESTIGADORES
LECOMTE Karina Leticia
artículos
Título:
Mineral Weathering in a Semiarid Mountain River: Its assessment through PHREEQC inverse modeling
Autor/es:
KARINA L. LECOMTE; ANDREA I. PASQUINI; PEDRO J. DEPETRIS
Revista:
AQUATIC GEOCHEMISTRY
Editorial:
Springer
Referencias:
Lugar: Netherlands; Año: 2005 vol. 11 p. 173 - 194
ISSN:
1380-6165
Resumen:
Abstract. By means of PHREEQC inverse modeling, we have simulated the weathering reactions
in Los Reartes River, a mountainous (2400?670 m a.s.l.) drainage basin from the Sierras
Pampeanas of Co´ rdoba, Argentina, analyzing the effect of lithology, relief, and climate. The
steep upper half of the basin (slopes >20%) is occupied by exposed granite; the remaining area is
mostly metamorphic, with cropping out gneisses and progressively decreasing slopes (<6%).
Climate is semihumid to semiarid; rainfall mainly occurs in summer and decreases with
decreasing height. PHREEQC inverse models developed using water chemical data showed that:
(a) oligoclase was the major supplier of solutes, while the main precipitated phase was kaolinite
in the granite domain; (b) muscovite is the chief supplier of solutes and illite is the main precipitated
phase in the gneissic realm; (c) the steeper portions of the metamorphic reach are less
crucial in supplying solutes than the lower ones, thus highlighting the importance of the water
residence time in the kinetics of dissolution; (d) in the driest time of the year (winter, 20 mm/
month) we registered the highest production of dissolved and precipitated phases; fluxes (mmol/
month), however, are higher at the end of the rainy season; (e) CO2 consumption is important all
along the Los Reartes drainage basin and, in terms of mmol/kg H2O, the lowermost portion of
the basin is the most significant supplier; (f) CO2 accounts for over 50% of all the species
involved in the weathering reactions occurring at the Los Reartes drainage basin.By means of PHREEQC inverse modeling, we have simulated the weathering reactions
in Los Reartes River, a mountainous (2400?670 m a.s.l.) drainage basin from the Sierras
Pampeanas of Co´ rdoba, Argentina, analyzing the effect of lithology, relief, and climate. The
steep upper half of the basin (slopes >20%) is occupied by exposed granite; the remaining area is
mostly metamorphic, with cropping out gneisses and progressively decreasing slopes (<6%).
Climate is semihumid to semiarid; rainfall mainly occurs in summer and decreases with
decreasing height. PHREEQC inverse models developed using water chemical data showed that:
(a) oligoclase was the major supplier of solutes, while the main precipitated phase was kaolinite
in the granite domain; (b) muscovite is the chief supplier of solutes and illite is the main precipitated
phase in the gneissic realm; (c) the steeper portions of the metamorphic reach are less
crucial in supplying solutes than the lower ones, thus highlighting the importance of the water
residence time in the kinetics of dissolution; (d) in the driest time of the year (winter, 20 mm/
month) we registered the highest production of dissolved and precipitated phases; fluxes (mmol/
month), however, are higher at the end of the rainy season; (e) CO2 consumption is important all
along the Los Reartes drainage basin and, in terms of mmol/kg H2O, the lowermost portion of
the basin is the most significant supplier; (f) CO2 accounts for over 50% of all the species
involved in the weathering reactions occurring at the Los Reartes drainage basin.2400?670 m a.s.l.) drainage basin from the Sierras
Pampeanas of Co´ rdoba, Argentina, analyzing the effect of lithology, relief, and climate. The
steep upper half of the basin (slopes >20%) is occupied by exposed granite; the remaining area is
mostly metamorphic, with cropping out gneisses and progressively decreasing slopes (<6%).
Climate is semihumid to semiarid; rainfall mainly occurs in summer and decreases with
decreasing height. PHREEQC inverse models developed using water chemical data showed that:
(a) oligoclase was the major supplier of solutes, while the main precipitated phase was kaolinite
in the granite domain; (b) muscovite is the chief supplier of solutes and illite is the main precipitated
phase in the gneissic realm; (c) the steeper portions of the metamorphic reach are less
crucial in supplying solutes than the lower ones, thus highlighting the importance of the water
residence time in the kinetics of dissolution; (d) in the driest time of the year (winter, 20 mm/
month) we registered the highest production of dissolved and precipitated phases; fluxes (mmol/
month), however, are higher at the end of the rainy season; (e) CO2 consumption is important all
along the Los Reartes drainage basin and, in terms of mmol/kg H2O, the lowermost portion of
the basin is the most significant supplier; (f) CO2 accounts for over 50% of all the species
involved in the weathering reactions occurring at the Los Reartes drainage basin.20 mm/
month) we registered the highest production of dissolved and precipitated phases; fluxes (mmol/
month), however, are higher at the end of the rainy season; (e) CO2 consumption is important all
along the Los Reartes drainage basin and, in terms of mmol/kg H2O, the lowermost portion of
the basin is the most significant supplier; (f) CO2 accounts for over 50% of all the species
involved in the weathering reactions occurring at the Los Reartes drainage basin.2 consumption is important all
along the Los Reartes drainage basin and, in terms of mmol/kg H2O, the lowermost portion of
the basin is the most significant supplier; (f) CO2 accounts for over 50% of all the species
involved in the weathering reactions occurring at the Los Reartes drainage basin.2O, the lowermost portion of
the basin is the most significant supplier; (f) CO2 accounts for over 50% of all the species
involved in the weathering reactions occurring at the Los Reartes drainage basin.2 accounts for over 50% of all the species
involved in the weathering reactions occurring at the Los Reartes drainage basin.