I know that under the chemical weathering Ferrous (Fe 2+) solve in the water and the because of Oxygen oxidized to the Ferric (Fe 3+) form.
The formation of the crystalline hematite, or any other consequence of the redox reaction, may affect the permeability of the soil or change the mechanical characteristics of it?
I can find the primary minerals that have Fe2+ on their structure, what secondary mineral may result from the redox reaction?
Thank you for your time.
Ebrahim
Please check this link and pdf attachments for said query.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4009779/
Hi Ebrahim, Chlorites and vermiculites, and mixed-clays may form in soils, for example from weathering of montmorillonite under some circumstances. Try to write the reaction to see what happens. More generally, see the work of N. Van Bremen on the effects of redox processes involving iron on the chemistry and mineralogy of reduced soils. All the best, Anicet
Drs. Arvind Singh and Anicet Beauvais have given good source of information. I agree with their views. However, Ebrahim Sangsefidi may consul book by Dixon and Weed "Minerals in soils" and Soil Physical chemistry (2nd Ed.) by DL Sparks.
Redox-related environmental issues have increased in importance in the last decades. Redox conditions regulate many of the biogeochemical reactions in the soil system and influence the physical and morphological properties. Redoximorphic features which plays a predominant role are morphological features associated with anaerobic conditions and formed by the reductive dissolution, translocation, and subsequent oxidation of Fe and Mn oxides in the soil.
For your reference see my attached chapter book that relates to this issue.
Chapter Fe–Mn Concretions and Nodules to Sequester Heavy Metals in Soils
Hi Ebrahim!
The formation of the crystalline hematite, affect the permeability of the soils and the mechanicals characteristics of their. Also affect on the other properties of soils (for example, the chemical properties and mineral composition).
Best regards.
Well, the classic about this subject is Ponnamperuma F.N. Effects of Flooding on Soils. In: Kozlowski T.T., editor. Flooding and Plant Growth. Academic Press Inc.; Orlando, FL, USA: 1984. pp. 1–44.
You can find an excellent discussion about Amazon soils under flooding also:
Dinamics of elements in soils from Amazonia after controlled inundation
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672005000300003
Reductive dissolution of iron oxide minerals by micobial activity on waterlogged soils can also generate ferrous iron in soil solutions. This can be seasonal particularly in soils with fluctuating water tables. Initial iron minerals produced on oxidation of the ferrous iron can range from ferrihydrite to schwertmannite and jarosite depending on pH during precipitation. These may later transform to othe iron oxides depending on transient coditions in the soil (temp, pH, redox salinity).
many valuable points mentioned above. in aspect of soil genesis and evaluation when chemical weathering happened Ferrous (Fe 2+) dissolved in the water and it could be accumulated in the subsurface horizons as Ferric (Fe3+) then under circumstance of wet and dry cycles cementation and hardening of horizons process take place. this process in tropical climate will generate "petroferric contact" "Oxic Horizon (normally 30 percent or more Fe2O3)" and "Plinthite
Hi Ebrahim,
As redoximorphic features Fe concentration formed in the pores, they tend to reduce soil porosity.
However with the advance of the oxidation processes may occur depletions clay (dispersal and migration and destruction of clay "ferrolysis) increasing porosity in some horizons.
See:
VEPRASKAS, M. J .; LINDBO, D. L. Redoximorphic features related to the soil hydrology and hydric soils. In: LIN, H. (Ed.). Hydropedology: synergistic integration of soil science and hydrology.Amstredam: Elsevier, 2012. p. 143-172.
Redox reaction is a simple indicator of oxidation -reduction process , no doubt , it will affect the physical properties of soils through elluviation/illuviation of clays plus changes in functional dynamics of microbes , together bring changes in distribution of aggregate size and their stability .
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