Petrography and geochemical study of central Ganga plain sediments, Aligarh – Mathura Region, Uttar Pradesh, India

Abstract

The sedimentological studies of Ganga and Yamuna sediments have practically been untouched. Therefore, an attempt has been made here to study the processes and products of river Ganga and Yamuna. The study area lies between 77031 to 78089 longitude and 27043 to 28036 latitude . During investigations seven stations were selected for detailed study. The present study mainly aims at reconstructing the sedimentation history of the Ganga plain. For this purpose three field sessions were planned and executed in January 2008, 2009, 2010 for detailed measurement of the sections and collection of samples for the follow up laboratory investigation. Forty one lithostratigraphic sections were measured from different localities. Thin sections of sand samples were prepared and used for petrographic study. The textural attributes of the sediments were studied. Bivariant plots were plotted to find out interrelationship of various textural attributes. Detrital mineralogy of the sediments including light and heavy minerals fractions, was studied for the purpose of description and petrographic classification of the studied sediments and interpretation of their provenance. Samples of sediments were choosen for geochemical analysis. Samples were analyzed by XRF and ICP-MS. The sand grains are medium to fine grained, moderately to well sorted, strongly fine skewed and platykurtic to leptokurtic. The grains are subangular to subrounded. Majority of the grains show low to high sphericity. The interrelationship of various textural parameters appear to be, normal thereby, suggesting that the original texture of the sediments newlineand by implication, original detrital modes are preserved and have not been affected by diagenetic processes. The detrital content of the studied sediments is mainly composed of several varieties of quartz followed by rock fragments, feldspar, mica and heavy minerals. All the sediment samples plotted near the Q pole, in the sublitharenite field.