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Initial stages of soil and clay mineral formation

Titel Englisch Initial stages of soil and clay mineral formation
Gesuchsteller/in Egli Markus
Nummer 129500
Förderungsinstrument Projektförderung (Abt. I-III)
Forschungseinrichtung Geographisches Institut Universität Zürich
Hochschule Universität Zürich – ZH
Hauptdisziplin Bodenkunde
Beginn/Ende 01.04.2010 - 31.03.2012
Bewilligter Betrag 135'336.00
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Keywords (6)

Weathering; Soil minerals; Alps; Proglacial area; Soil chronosequence; chronosequence

Lay Summary (Englisch)

Lead
Lay summary
Chemical weathering of rocks is important for the generation of soils, for the evolution of landscape, and as a main source of inorganic nutrients for plant growth and therefore for life. A major interest in chemical and physical denudation of rocks is also due to its potential to affect the local up to global cycle of elements. A main gap in knowledge exists about the velocity of (clay) mineral transformations or formations in soils or material starting to be a soil in high alpine and arctic climate zones. Investigations of Alpine soils indicate that mineral weathering is much faster in young soils (< 1000 yrs) than in old soils (~10 000 y). However, little is known about the initial stages of weathering and soil formation, i.e. during the first decades of soil genesis. In this study we will investigate rock-forming minerals weathering and clay minerals formation during this time span. Due to the continuous retreat of the Morteratsch glacier (Upper Engadine, Swiss Alps), the proglacial area (granodiorite, diorite) offers a full time sequence from 0 to 150 yrs old surfaces. A special interest is given to biotite, chlorite, apatite, plagioclase and calcite. In addition, analyses of the stream water from the main channel, tributaries and of rainwater have been performed with a special focus on Ca/Sr and Sr isotope ratios (87Sr/86Sr). The high Ca/Sr as well as 87Sr/86Sr ratios confirm that Ca bearing minerals are weathering and transforming at very high rates in the proglacial area. Biotite has been continuously transformed into illite-like components. Regarding the clay minerals, special emphasis will be given to the formation of hydroxy-interlayered vermiculite, vermiculite and smectites. Preliminary results suggest that they are formed at very high rates. In addition to this, in detail investigations of Sr-isotopes in the stream water, springs, rock minerals, soils and plants (Epilobium fleischeri and Larix decidua) will furnish precious insight into the weathering mechanisms. Microbiological investigations about the microbial communities extracted from soil, rhizosphere and stream water along the chronosequence allow to monitor the soil microflora and its correlation with chemical and mineralogical soil characteristics. The planned investigations will give a detailed insight into the velocity of weathering processes with a high temporal and spatial resolution. By the use of an existing vegetation monitoring in the proglacial area of Morteratsch, soil map and digital elevation model, the role of topography and vegetation on chemical weathering can be analysed in detail in the proglacial area.
Direktlink auf Lay Summary Letzte Aktualisierung: 21.02.2013

Verantw. Gesuchsteller/in und weitere Gesuchstellende

Mitarbeitende

Name Institut

Publikationen

Publikation
Clay mineral evolution along a soil chronosequence in an Alpine proglacial area
Mavris C. Plötze M. Mirabella A. Giaccai D. Valboa G. Egli M. (2011), Clay mineral evolution along a soil chronosequence in an Alpine proglacial area, in Geoderma, 165, 106-117.
Fast but spatially scattered smectite-formation in the proglacial area Morteratsch: an evaluation using GIS
Egli M. Wernli M. Burga C. Kneisel C. Mavris C. Valboa G. Mirabella A. Plötze M. Hae (2011), Fast but spatially scattered smectite-formation in the proglacial area Morteratsch: an evaluation using GIS, in Geoderma, 164, 11-21.
Initial pedogenesis in a recently exposed Alpine proglacial area
Mavris C. Egli M. Plötze M. Haeberli W. (2010), Initial pedogenesis in a recently exposed Alpine proglacial area, in Acta Mineralogica-Petrographica, 6, 639-639.
Soil organic matter formation along a chronosequence in the Morteratsch proglacial area (Upper Engadine, Switzerland)
Egli M. Mavris C. Mirabella A. Giaccai D. Kägi B. Haeberli W. (2010), Soil organic matter formation along a chronosequence in the Morteratsch proglacial area (Upper Engadine, Switzerland), in Catena, 82, 61-69.
Initial stages of weathering and soil formation in the Morteratsch proglacial area (Upper Engadine, Switzerland)
Mavris C. Egli M. Plötze M. Blum J. Mirabella A. Giaccai D. Haeberli W. (2010), Initial stages of weathering and soil formation in the Morteratsch proglacial area (Upper Engadine, Switzerland), in Geoderma, 155, 359-371.
Plant succession and soil development on the foreland of the Morteratsch glacier (Pontresina, Switzerland): Straight forward or chaotic?
Burga C.A. Krüsi B. Egli M. Wernli M. Elsener S. Ziefle M. Mavris C. (2010), Plant succession and soil development on the foreland of the Morteratsch glacier (Pontresina, Switzerland): Straight forward or chaotic?, in Flora, 205, 561-576.
Initial stages of soil and clay minerals formation in the Morteratsch proglacial area (Upper Engadine, Switzerland)
Mavris C. Egli M. Plötze M. Blum J. Haeberli W. (2009), Initial stages of soil and clay minerals formation in the Morteratsch proglacial area (Upper Engadine, Switzerland).
Weathering and mineralogical evolution in a high Alpine soil chronosequence: a combined approach using SEM-EDX, cathodoluminescence and Nomarski DIC microscopy.
Mavris C. Götze J. Plötze M. W. Egli M., Weathering and mineralogical evolution in a high Alpine soil chronosequence: a combined approach using SEM-EDX, cathodoluminescence and Nomarski DIC microscopy., in Sedimentary Geology.

Wissenschaftliche Veranstaltungen

Aktiver Beitrag

Titel Art des Beitrags Titel des Artikels oder Beitrages Datum Ort Beteiligte Personen
1st International Mindat.org Conference 10.07.2011 Lwowek Slaski, Poland
GGG seminary 30.11.2010 Munich, Germany
20th IMA Conference 21.08.2010 Budapest, Hungary
7th Swiss Geoscience Meeting 20.11.2009 Neuchâtel
14th International Clay Conference 14.06.2009 Castellaneta Mare, Italy


Auszeichnungen

Titel Jahr
Award of the SIMP 2009

Verbundene Projekte

Nummer Titel Start Förderungsinstrument
117568 Initial stages of soil and clay mineral formation 01.04.2008 Projektförderung (Abt. I-III)

Abstract

Chemical weathering of rocks is extremely important for the generation of soils, for the evolution of landscape, and as a main source of inorganic nutrients for plant growth and therefore for life. A major interest in chemical and physical denudation of rocks is also due to its potential to affect the local up to global cycle of elements. A main gap in knowledge exists about the velocity of (clay) mineral transformations or formations in soils or material starting to be a soil in high alpine and arctic climate zones. Investigations of Alpine soils indicate that mineral weathering is much faster in ‘young’ soils (< 1000 yrs) than in ‘old’ soils (~10 000 ysr). However, little is known about the initial stages of weathering and soil formation, i.e. during the first decades of soil genesis. In this study we will investigate rock-forming minerals weathering and clay minerals formation during this time span. Due to the continuous retreat of the Morteratsch glacier (Upper Engadine, Swiss Alps), the proglacial area (granodiorite, diorite) offers a full time sequence from 0 to 150 yrs old surfaces. The area is well documented regarding vegetation and soils. Among the primary minerals, a special interest is given to biotite, chlorite, apatite, plagioclase and calcite. Mineralogical measurements have been carried out on the bulk soil fraction (< 2 mm) using XRD for qualitative and quantitative phase analysis. In addition, analyses of the stream water from the main channel, tributaries and of rainwater have been performed with a special focus on Ca/Sr and Sr isotope ratios (87Sr/86Sr). The high Ca/Sr as well as 87Sr/86Sr ratios confirm that Ca bearing minerals are weathering and transforming at very high rates in the proglacial area. Biotite has been continuously transformed into illite-like components. Also in cryic, ice-free environments, chemical weathering rates are high leading to the formation and transformation of minerals. Disseminated calcite in granitoid rocks, not confined to sedimentary carbonate rocks, also plays a role in subglacial environments. The high Ca/Na and Ca/Sr ratio in the stream and tributary waters show that calcite contributes to the supply of soluble Ca, although the ion activity product calculations clearly demonstrated that the waters are undersaturated with respect to this mineral.Regarding the clay minerals, special emphasis will be given to the formation of hydroxy-interlayered vermiculite (HIV), vermiculite and smectites. Preliminary results suggest that they are formed at very high rates. Consequently, the clay fraction as well as the fraction 2 – 32 µm and the fine earth (< 2 mm) will be studied in detail regarding (clay) minerals. Furthermore, element mass balances (leaching of elements from soils) will be of special interest. In addition to this, in detail investigations of Sr-isotopes (86Sr/87Sr) in the stream water, springs, rock minerals, soils and plants (Epilobium fleischeri and Larix decidua) will furnish precious insight into the weathering mechanisms. The planned investigations will give a detailed insight into the velocity of weathering processes (element denudation, mineral formations and transformations) with a high temporal (decades: 0 – 150 yrs) and spatial resolution. By the use of an existing vegetation monitoring in the proglacial area of Morteratsch, soil map and digital elevation model, the role of topography and vegetation on chemical weathering can be analysed in detail in the proglacial area. Surprisingly, soil formation is more advanced at north-facing sites – further investigation of the clay minerals will reveal if such a trend can also be detected regarding this aspect. Additionally, soil microbiological analyses along the chronosequence are planned. Microbiological investigations about the microbial communities (eubacteria, actinomycetes and fungi) by genetic fingerprinting (Denaturing Gradient Gel Electrophoresis, DGGE) of SSU rRNA genes of DNA extracted from soil, rhizosphere and stream water along the chronosequence allow to assess and monitor the soil microflora and its correlation with chemical and mineralogical soil characteristics. With the help of such a chronosequence initial stages of soil formation, mineral weathering, transformations and formations can be studied and, therefore, also initial stages of life. Understanding the processes on a small scale is of major importance and will provide process mechanisms that can be used as a basis for modelling and/or extrapolation to other proglacial areas.
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