Significance of silica in identifying the processes affecting groundwater chemistry in parts of Kali watershed, Central Ganga Plain, India

Arina Khan,Rashid Umar,Haris Hasan Khan

doi:10.1007/s13201-014-0164-z

Arina Khan, Rashid Umar + Show 1 more

Open Access

https://doi.org/10.1007/s13201-014-0164-z

Copy DOI

Abstract

Chemical geothermometry using silica was employed in the present study to estimate the sub-surface groundwater temperature and the corresponding depth of the groundwater in parts of Kali watershed in Bulandshahr and Aligarh district. 42 groundwater samples each were collected from borewells during pre-monsoon and post-monsoon season 2012 and analysed for all major ions and silica. Silica values in the area range from 18.72 to 50.64 mg/l in May 2012 and from 18.89 to 52.23 mg/l in November 2012. Chalcedony temperature >60 °C was deduced for five different locations in each season, which corresponds to a depth of more than 1,000 metres. Spatial variation of silica shows high values along a considerable stretch of River Kali, during pre-monsoon season. Relationship of silica with Total Dissolved Solids and Chloride was established to infer the role of geogenic and anthropogenic processes in solute acquisition. It was found that both water–rock interaction and anthropogenic influences are responsible for the observed water chemistry.

Highlights

Groundwater temperature is a direct indicator of geothermal influence
Chemical geothermometry using silica was employed in the present study to estimate the sub-surface groundwater temperature and the corresponding depth of the groundwater in parts of Kali watershed in Bulandshahr and Aligarh district. 42 groundwater samples each were collected from borewells during pre-monsoon and postmonsoon season 2012 and analysed for all major ions and silica
Silica geothermometry was applied on thermal groundwaters in the Gulf of Suez region, Egypt (El-Fiky 2009) and the results showed that the sub-surface temperatures range between 29.4 and 104.5 °C

Summary

Introduction

Groundwater temperature is a direct indicator of geothermal influence. Chemical geothermometry is a technique that can be used to estimate sub-surface reservoir temperatures using concentration of certain elements in groundwater. Geothermometers provide important information on the reservoir temperatures. They are based on temperaturedependent mineral equilibria. The information obtained from geothermometers is inexpensive and reliable. The quartz and Na–K geothermometers are the most commonly used chemical geothermometers (Hailemichael 2008). The predicted temperatures generally show a wide dispersion even when applying a single geothermometer to all the wells in an area. Many reasons have been proposed to justify the discrepancies, including gain or loss of steam phase in the reservoir, mixing of different types of fluids, re-equilibration during ascension to superficies, precipitation–dissolution, etc. Many reasons have been proposed to justify the discrepancies, including gain or loss of steam phase in the reservoir, mixing of different types of fluids, re-equilibration during ascension to superficies, precipitation–dissolution, etc. (Truesdell and Fournier 1977; Verma 2000)

Methods

Results

Conclusion