『Abstract
　We investigated chemical weathering in a high elevation granitic environment in three selected watersheds located in the Pyrenees (France). The sites were located on glacial deposits derived from similar Hercynian (〜300 Ma) granites characterized by the occurrence of zoned plagioclases and trace calcic phases (epidote, prehnite, sphene, apatite). The surface waters at those sites show high Ca/Na molar ratios (＞1) which could not be explained by the dissolution of the major plagioclase (oligoclase) present in the rocks. The coupled approach of investigating stream water chemistry and the mineralogy and chemistry of rocks and soils allowed us to explore the role of the weathering of trace calcic minerals in calcium export at the watershed scale. The weathering of the trace calcic minerals which represent 〜1％ of the total rock volume are responsible for more than 90％ of the calcium export at the sites. Annual cationic fluxes (〜23.10⁴ eq/km²/yr) calculated for the Esribere（最初のeの頭に´） watershed are among the highest reported for high elevation systems draining granitic rocks and 〜80％ of this annual cationic flux can be attributed to the weathering of trace calcic phases. Calculations based on isotopic values (⁸⁷Sr/⁸⁶Sr) go in the same direction. Except apatite, the trace calcic phases appear to be mainly silicates, thus the type of chemical weathering observed in the Esribere（最初のeの頭に´） watershed may have an influence on atmospheric CO2 consumption by granitic weathering. However, comparison with other watersheds draining granitic environments worldwide, and with the two other sites in the Pyrenees, indicate that the role of trace calcic phases is important in most young environments exposed to chemical weathering (e.g., high elevation catchments on glacial deposits). Other factors such as the date of glacial retreat, the physical denudation rate, the hydrological functioning of the watershed and the nature and structure of the soil cover are also important.』

1. Introduction
2. Geological and geographical setting
　2.1. The Esribere（最初のeの頭に´） watershed
　2.2. The Bassies massif and the Escale stream
　2.3. The Trois Seigneurs massif and its streams
　2.4. Climatic and hydrological setting of the study
3. Material and methods
4. Results
　4.1. Bedrock and soil mineralogy and chemistry
　　4.1.1. The Esribere（最初のeの頭に´） parental monzogranite and soils
　　4.1.2. The Bassies parental monzogranite
　　4.1.3. The Trois Seigneur granodiorite
　4.2. Stream water chemistry
5. Discussion
　5.1. Input-output budget for the Esribere（最初のeの頭に´） watershed
　5.2. The molar Ca/Na ratios of granite weathering
　5.3. Determination of the probable solute sources in the Esribere（最初のeの頭に´） watershed
　　5.3.1. Atmospheric “red dust” deposition
　　5.3.2. The occurrence of mylonitic assemblages
　　5.3.3. The effect of vegetation
　5.4. The weathering of trace phases: The problem of mass balance calculations
　5.5. The weathering of trace phases: ⁸⁷Sr/⁸⁶Sr investigations
　5.6. Implications of the present study: Importance of mountainous areas and the chemical weathering of trace phases in the global co budget
6. Summary and conclusion
Acknowledgments
References
Appendix 1. Chemical analysis of mineral from the Neouvielle monzogranite.
Appendix 2. Chemical analysis of amphibole and allanite from the Trois Segneurs granodiorite.