Aquatic Geochemistry

, Volume 17, Issue 4–5, pp 357–396 | Cite as

Dolomite Versus Calcite Weathering in Hydrogeochemically Diverse Watersheds Established on Bedded Carbonates (Sava and Soča Rivers, Slovenia)

  • Kathryn SzramekEmail author
  • Lynn M. Walter
  • Tjaša Kanduč
  • Nives Ogrinc
Original Paper


The relative contributions of dolomite to calcite weathering related to riverine fluxes are investigated on a highly resolved spatial scale in the diverse watersheds of Slovenia, which previous work has shown have some of the highest carbonate-weathering intensities in the world and suggests that dolomite weathering is favored over limestone weathering in mixed carbonate watersheds. The forested Sava and Soča River watersheds of Slovenia with their headwaters in the Julian Alps drain alpine regions with thin soils (<30 cm) and dinaric karst regions with thicker soils (0 to greater than 70 cm) all developed over bedded Mesozoic carbonates (limestone and dolomite), and siliclastic sediments is the ideal location for examining temperate zone carbonate weathering. This study extends previous work, presenting geochemical data on source springs and documenting downstream geochemical fluctuations within tributaries of the Sava and Soča Rivers. More refined sampling strategies of springs and discrete drainages permit directly linking the stream Mg2+/Ca2+ ratios to the local bedrock lithology and the HCO3 concentrations to the relative soil depths of the tributary drainages. Due to differences in carbonate source lithologies of springs and tributary streams, calcite and dolomite weathering end members can be identified. The Mg2+/Ca2+ ratio of the main channel of the Sava River indicates that the HCO3 concentration can be attributed to nearly equal proportions by mass of dolomite relative to calcite mineral weathering (e.g., Mg2+/Ca2+ mole ratio of 0.33). The HCO3 concentration and pCO2 values increase as soil thickness and alluvium increase for discrete spring samples, which are near equilibrium with respect to calcite. Typically, this results in approximately 1.5 meq/l increase in HCO3 from the alpine to the dinaric karst regions. Streams in general do not change in HCO3 , Mg2+/Ca2+, or Mg2+/HCO3 concentrations down course, but warming and degassing of CO2 produce high degrees of supersaturation with respect to calcite. Carbonate-weathering intensity (mmol/km2-s) is highest within the alpine regions where stream discharge values range widely to extreme values during spring snowmelt. Overall, the elemental fluxes of HCO3 , Ca2+, and Mg2+ from the tributary watersheds are proportional to the total water flux because carbonates dissolve rapidly to near equilibrium. Importantly, dolomite weathers preferentially over calcite except for pure limestone catchments.


Dolomite Carbonate Weathering Rivers Slovenia Watersheds Fluxes 



We acknowledge the support of the National Science Foundation (EAR-0208182 and EAR-05-18965) and the Slovenian Research Agency. We thank the following people for their invaluable assistance in the field and laboratory: Corey Lambert, Nina Carranco, Lixin Jin, and Jennifer Macintosh. We extend our thanks to the anonymous reviewers who helped improve this manuscript.


  1. Amiotte Suchet P, Probst JL (1993) Modeling of atmospheric CO2 consumption by chemical weathering of rocks: application to the Garonne, Congo and Amazon basins. Chem Geol 107:205–210CrossRefGoogle Scholar
  2. Amiotte Suchet P, Probst JL (1995) A global model for present-day atmospheric/soil CO2 consumption by chemical erosion of continental rocks (GEM-CO2). Tellus 47B:273–280Google Scholar
  3. Amiotte Suchet P, Probst JL, Ludwig W (2003) Worldwide distribution of continental rock lithology: implications for the atmospheric/soil CO2 uptake by continental weathering and alkalinity river transport to the oceans. Global Biogeochem Cycles 17:1038CrossRefGoogle Scholar
  4. Anderson SP, Drever JI, Frost CD, Holden P (2000) Chemical weathering in the foreland of a retreating glacier. Geochim Cosmochim Acta 64:1173–1189CrossRefGoogle Scholar
  5. Berner EK, Berner RA (1996) Global environment: water, air, and geochemical cycles, 1st edn. Prentice-Hall, Upper Saddle River New JerseyGoogle Scholar
  6. Berner RA, Lasaga AC, Garrels RM (1983) The carbonate-silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 million years. Am J Sci 283:641–683CrossRefGoogle Scholar
  7. Bluth GJS, Kump LR (1994) Lithologic and climatologic controls of river chemistry. Geochim Cosmochim Acta 58:2341–2359CrossRefGoogle Scholar
  8. Brook GA, Folkoff ME, Box EO (1983) A world model of soil carbon dioxide. Earth Surf Process Landf 8:79–88CrossRefGoogle Scholar
  9. Dessert C, Dupre B, Gaillardet J, Francois LM, Allegre CJ (2003) Basalt weathering laws an the impact of basalt weathering on the global carbon cycle. Chem Geol 202:257–273CrossRefGoogle Scholar
  10. Drever JI (1997) The geochemistry of natural waters: surface and groundwater environments. Prentice-Hall, New JerseyGoogle Scholar
  11. Dürr HH, Meybeck M, Dürr SH (2005) Lithologic composition of the earth’s continental surfaces derived from a new digital map emphasizing riverine material transfer. Global Biogeochem Cycles 19:GB4S10CrossRefGoogle Scholar
  12. EWN-SI (2003) European Environment Information and Observation Network (EIONET), EIONET in Slovenia.
  13. Fairchild IJ, Killawee JA, Sharp MJ, Spiro B, Hubbard B, Lorrain RD, Tison J-L (1999) Solute generation and transfer from a chemically reactive alpine glacial-proglacial system. Earth Surf Process Landf 24:1189–1211CrossRefGoogle Scholar
  14. Frantar P, Dolinar M, Kurnik B (2008) Water balance of Slovenia 1971–2000 IOP Conf Ser: Earth Environ Sci 4:012020Google Scholar
  15. Gabrovec M (1995) Dolomite areas in Slovenia with particular consideration of relief and land use. Geogr zbornik 35:7–44Google Scholar
  16. Gaillardet J, Dupré B, Louvat P, Allègre CJ (1999) Global silicate weathering and CO2 consumption rates deduced from the chemistry of large rivers. Chem Geol 159:3–31CrossRefGoogle Scholar
  17. Galy A, France-Lanord C (1999) Weathering processes in the Ganges-Brahmaputra basin and the riverine alkalinity budget. Chem Geol 159:31–60CrossRefGoogle Scholar
  18. Gieskes JM, Rogers WC (1973) Alkalinity determinations in interstitial waters of marine sediments. J Sediment Petrol 43:272–277Google Scholar
  19. Han G, Liu C-Q (2004) Water geochemistry controlled by carbonate dissolution: a study of the river waters draining karst-dominated terrain, Guizhou Province, China. Chem Geol 204:1–21CrossRefGoogle Scholar
  20. Hercod DJ, Brady PV, Gregory RT (1998) Catchment-scale coupling between pyrite oxidation and calcite weathering. Chem Geol 151:259–276CrossRefGoogle Scholar
  21. Herman JS, Lorah MM (1987) CO2 outgassing and calcite precipitation in Falling Spring Creek, Virginia. U.S.A. Chem Geol 62:251–262CrossRefGoogle Scholar
  22. Huh Y, Tsoi M, Zaitsev A, Edmond JM (1998) The fluvial geochemistry of the rivers of Eastern Siberia: I. Tributaries of the Lena River draining the sedimentary platform of the Siberian Craton. Geochim Cosmochim Acta 62:1657–1676CrossRefGoogle Scholar
  23. Jin L, Williams E, Szramek K, Walter LM, Hamilton SK (2008) Silicate and carbonate mineral weathering in soil profiles developed on Pleistocene glacial drift (Michigan, USA): mass balances based on soil water geochemistry. Geochim Cosmochim Acta 72:1027–1042CrossRefGoogle Scholar
  24. Jin L, Ogrinc N, Hamilton SK, Szramek K, Kanduč T, Walter LM (2009) Inorganic carbon isotope systematics in soil profiles undergoing silicate and carbonate weathering (Southern Michigan, USA). Chem Geol 264:139–153CrossRefGoogle Scholar
  25. Kanduč T, Ogrinc N, Szramek K, Walter LM (2005) Hydrogeochemical and stable isotope characteristics of the Sava River Basin, Slovenia. 7th Hellenic hydrogeological conference vol II, pp 233–239Google Scholar
  26. Kanduč T, Szramek K, Ogrinc N, Walter LM (2007) Origin and cycling of riverine inorganic carbon in the Sava River watershed (Slovenia) inferred from major solutes and stable carbon isotopes. Biogeochemistry 86:137–154CrossRefGoogle Scholar
  27. Kanduč T, Kocman D, Ogrinc N (2008) Hydrogeochemical and stable isotope characteristics of the River Idrijca (Slovenia) the boundary watershed between the Adriatic and Black Seas. Aquatic Geochem 14:239–262CrossRefGoogle Scholar
  28. Kharaka YK, Gunter WD, Aggarwal PK, Perkins EH, DeBraal JD (1988) SOLMINEQ.88: a computer program for geochemical modeling of water-rock interactions. U.S. Geological SurveyGoogle Scholar
  29. Kump LR, Brantley SL, Arthur MA (2000) Chemical weathering, atmospheric CO2, and climate. Annu Rev Earth Planet Sci 28:611–667CrossRefGoogle Scholar
  30. Langmuir D (1997) Aqueous environmental geochemistry. Prentice-Hall, New JerseyGoogle Scholar
  31. Lee RW (1997) Effects of carbon dioxide variations in the unsaturated zone on water chemistry in a glacial-outwash aquifer. Appl Geochem 12:347–366CrossRefGoogle Scholar
  32. Markovics R, Kanduč T, Szramek K, Golobočanin D, Milačič R, Ogrinc N (2010) Chemical dynamics of the Sava riverine system. J Environ Monit 12:2165–2176CrossRefGoogle Scholar
  33. Meybeck M (1987) Global chemical weathering of surficial rocks estimated from river dissolved loads. Am J Sci 287:401–428CrossRefGoogle Scholar
  34. Millot R, Gaillardet J, Dupré B, Allègre CJ (2003) Northern latitude chemical weathering rates: clues from the Mackenzie River Basin, Canada. Geochim Cosmochim Acta 67:1305–1329CrossRefGoogle Scholar
  35. Oliva P, Viers J, Dupré B (2003) Chemical weathering in granitic environments. Chem Geol 202:225–256CrossRefGoogle Scholar
  36. Palmer CD, Cherry JA (1984) Geochemical evolution of groundwater in sequences of sedimentary rocks. J Hydrol 75:27–65CrossRefGoogle Scholar
  37. Pawellek F, Frauenstein F, Veizer J (2002) Hydrochemistry and isotope geochemistry of the upper Danube River. Geochim Cosmochim Acta 66:3839–3854CrossRefGoogle Scholar
  38. Roy S, Gaillardet J, Allègre CJ (1999) Geochemistry of dissolved and suspended loads of the Seine river, France: anthropogenic impact, carbonate and silicate weathering. Geochim Cosmochim Acta 63:1277–1292CrossRefGoogle Scholar
  39. Stallard RF, Edmond JM (1981) Geochemistry of the Amazon 1, precipitation chemistry and the marine contribution to the dissolved load at the time of peak discharge. J Geophys Res 86:9844–9858CrossRefGoogle Scholar
  40. Stallard RF, Edmond JM (1983) Geochemistry of the Amazon 2, the influence of geology and weathering environment on the dissolved load. J Geophys Res 88:9671–9688CrossRefGoogle Scholar
  41. Suarez DL (1983) Calcite supersaturation and precipitation kinetics in the Lower Colorado River, all American Canal and East Highline Canal. Water Resour Res 19:653–661CrossRefGoogle Scholar
  42. Szramek K, Walter LM (2004) Impact of carbonate precipitation on riverine inorganic carbon mass transport from a mid-continent, forested watershed. Aquatic Geochem 10:99–137CrossRefGoogle Scholar
  43. Szramek K, McIntosh JC, Williams EL, Kanduč T, Ogrinc N, Walter LM (2007) Relative weathering intensity of calcite vs. dolomite in carbonate-bearing temperate zone watersheds: carbonate geochemistry and fluxes from catchments within the St. Lawrence and Danube River Basin. Geochem Geophys Geosyst 8:1–28CrossRefGoogle Scholar
  44. Vidic N (1998) Soil-age relationships and correlations; comparison of chronosequences in the Ljubljana Basin, Slovenia and USA. Catena 34:113–129CrossRefGoogle Scholar
  45. Vidic N, Pavich MJ, Lobnik F (1991) Statistical analyses of soil properties on a quaternary terrace sequence in the upper Sava River valley, Slovenia, Yugoslavia. Geoderma 51:189–212CrossRefGoogle Scholar
  46. White AF, Blum AE (1995) Effects of climate on chemical weathering in watersheds. Geochim Cosmochim Acta 59:1729–1747CrossRefGoogle Scholar
  47. White AF, Schulz MS, Lowenstern JB, Vivit DV, Bullen TD (2005) The ubiquitous nature of accessory calcite in granitoid rocks: implications for weathering, solute evolution, and petrogenesis. Geochim Cosmochim Acta 69:1455–1471Google Scholar
  48. Williams E, Szramek K, Jin L, Ku TCW, Walter LM (2007) The carbonate system geochemistry of shallow groundwater/surface water systems in temperate glaciated watersheds (Michigan, USA): significance of open system dolomite weathering. Geol Soc Am Bull 119:511–528CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Kathryn Szramek
    • 1
    • 3
    Email author
  • Lynn M. Walter
    • 1
  • Tjaša Kanduč
    • 2
  • Nives Ogrinc
    • 2
  1. 1.Department of Geological SciencesUniversity of MichiganAnn ArborUSA
  2. 2.Department of Environmental SciencesJ. Stefan InstituteLjubljanaSlovenia
  3. 3.Environmental SciencesDrake UniversityDes MoinesUSA

Personalised recommendations