Mineralogy of Soils along Toposequence in Raipur District of Chattisgarh

Abstract

The mineralogical compositions alongwith physical, chemical, elemental and mineralogical properties of four pedons occurring along a toposequence in Chhota Urla village (Abhanpur tehsil) Raipur district of _ Chhattisgarh state were studied. Landform had significant influence on physical, 1 chemical, elemental and mineralogical properties of soils. Sand content decreased from higher topography to lower topography but clay content increased with decrease in elevation. pH of pedons ranged from strongly acid to moderately alkaline and CEC increased from upland to lowland. Quartz being dominant in sand fraction and absence of primary minerals like Ca-feldspar, K-feldspar indicated intense weathering of soils. Silt had quartz as dominant mineral followed by Ca- feldspar and K-feldspar. Kaolin was dominant mineral in clay fractions of Pedons I and 2 (PI and P2) with sub-ordinate amount of smectite while smectite was dominant in other two pedons followed by kaolin. Huge amount of smectite which is first weathering product of plagioclase, did not find its parental legacy with underlying geology (sandstone, limestone and shale sequence) indicative of mixed alluvium, eroded from different geological formation and contradicted the occurrence of catenary sequence as reported earlier.