Geospatial Mapping of Minerals Identified Using X-ray Diffraction in the Soils of Punjab State in the North-West of Indian Subcontinent

Satellite image interpretation of 1:2,50,000 scale Landsat 4 MSS (band 2, 3, 4) composites was undertaken for delineating landforms using visual elements followed by transfer of physiographic boundaries on 1:2,50,000 scale Survey of India toposheets, which were used as base map for soil resource mapping of Punjab state. One hundred and fifty-one surface samples pertaining to all the soil mapping units representing dominant soil families of Punjab were collected using global positioning system. Samples were prepared and analysed for physical, chemical and mineralogical analysis using standard procedures. Mineral suite of coarse and fine fraction of soils of the Punjab state was identified using X-ray diffraction. In sand size mineral assemblage, quartz dominated with a decreasing abundance of mica, feldspar, chlorite and calcite minerals in all the agro-eco-subregions except the south-western agro-eco-subregion, where mica dominated. Geospatial thematic mapping of mineral assemblage of different fractions of soils was carried out using ArcGIS 9.2. Among the coarse fraction minerals; the QFMCCA mineral association (Q: quartz, F: feldspar, M: mica, C: chlorite, CA: calcite) occupied 48.40 per cent of the state in the districts of Gurdaspur, Amritsar, Hoshiarpur, Nawanshahr and Tarn Taran. The FCMQCA mineral association (F: feldspar, C: chlorite, M: mica, Q: quartz, CA: calcite) covered only 0.28 per cent area of the state. In the fine fraction mineralogy, illite dominated with decreasing order of chlorite, kaolinite, vermiculite, mixed layer and smectite. Fourteen sand size mineral associations were mapped. In the clay size mineral assemblage, twenty-three associations were identified and mapped. The ICKMVS mineral association (I: illite, C: chlorite, K: kaolinite, M: mixed layer, V: vermiculite and S: smectite) covered 23.08 per cent of the state in the districts of Bathinda and Muktsar. The ICVKSM (I: illite, C: chlorite, V: vermiculite, K: kaolinite, S: smectite, M: mixed layer) association covered only 0.03 per cent area in the district Hoshiarpur. Illite dominated in twenty-two mineral associations. Smectite was dominant in only one minerals association SKIVCM (S: smectite, K: kaolinite, I: illite, V: vermiculite, C: chlorite and M: mixed layer) representing 0.52 per cent of the state in the districts of Patiala and Fatehgarh Sahib. The mineral assemblage seems to relate directly to the source of alluvium that formed the parent material of these soils irrespective of their geomorphological position. Most of the minerals in sand as well as clay fraction seem to be transported as such. If there is any alteration in the minerals, it must have taken place prior to their transportation by the ancient river system in the geological stage itself.

Automated summary

Interpretation of satellite images and mineral analysis were used to identify soil mineral assemblages in different micro-regions of Punjab state. The study found that most minerals in sand and clay fractions seem to have been transported as such.