Sabarathinam Chidambaram - Profile on Academia.edu (original) (raw)

Papers by Sabarathinam Chidambaram

Signatures of Dryas Groundwater in Stratified Aquifers of Kuwait-Paleoclimatic Significance

New Prospects in Environmental Geosciences and Hydrogeosciences, 2022

Environmental Earth Sciences, 2014

The present study aims to investigate the concentration and spatial distribution of trace metals ... more The present study aims to investigate the concentration and spatial distribution of trace metals in Tamirabarani river and estuary located in the southeast coast of India. Sediment samples collected from sixteen locations were analysed for Cu, Ni, Cr, Pb, Zn and Cd. The extent of pollution in these sediments was assessed using enrichment factor (EF), contamination factor (CF), geo-accumulation index (I geo ). The EF shows enrichment of Ni in the northern part of the estuary and that of Cu in the south and it is mainly due to the process of weathering. The contamination factor indicates Cd is more highly contaminated than other metals. I geo index shows that Cd is moderately polluted and its spatial distributions clearly indicate that it is found in estuarine region. The comparison of metal concentration with other estuaries of India indicates that these metals are well below the permissible limit. The metals in the estuary of the study area indicate more of the predominance of natural process than other estuaries in India. It is evident that the samples of river and estuary area are dominantly due to the natural process rather than anthropogenic activity.

Stable Isotopic Signatures for Hydrogeochemical Characterisation of Ground Water from Pondicherry to Nagapattinam, Tamil Nadu

Management of Water, Energy and Bio-resources in the Era of Climate Change: Emerging Issues and Challenges, 2014

Groundwater recharge is a critical hydrological parameter. Identification of recharge zones and r... more Groundwater recharge is a critical hydrological parameter. Identification of recharge zones and recharge estimates are essential to water resources management (Scanlon and Cook, 2002; Raju et al., 2006). In recent years, the overgrowing population and climate change are putting water resources under pressure all over the world. Sustainable management of aquifers to meet human and ecosystem needs will require protection of recharge areas and their augmentation (Reddy et al., 2000).

Online Journal of Earth Sciences, 2010

Hydrochemistry of groundwater from Tuticorin District, Tamil Nadu, India

ABSTRACT The study area being a hard rock terrain with minimal rainfall and large extraction of g... more ABSTRACT The study area being a hard rock terrain with minimal rainfall and large extraction of groundwater for domestic, irrigational and industrial purposes have threatened the groundwater environment both in the conditions of quality and quantity. Hence an attempt has been made to classify the major geochemical process activated for controlling the ground water chemistry. Groundwater was generally alkaline with higher EC values. The dominance of anions and cations were of the order of Cl->HCO3->SO4 2->H4SiO4>NO3->F-and Na + >Ca 2+ >Mg 2+ >K +. The plot for Na + /Cl-to EC indicates Na + released from silicate weathering and Cl-from anthropogenic activities. The plot for Ca 2+ +Mg 2+ to SO4 2-+ HCO3-, indicates ion exchange process. Thermodynamic plot indicates that groundwater is in equilibrium with kaolinite, muscovite and chloride minerals. In general, water chemistry is guided by complex weathering process, ion exchange. Saturation index of Carbonate and Sulphate minerals indicates under saturation to oversaturation and Silicate minerals were at equilibrium to oversaturation state.

Delineation of Natural and Anthropogenic Process Controlling Hydrogeochemistry of Layered Aquifer Sequence

Proceedings of the National Academy of Sciences, India Section A: Physical Sciences, 2014

ABSTRACT Groundwater is the source for many activities in urban regions and the quality plays a s... more ABSTRACT Groundwater is the source for many activities in urban regions and the quality plays a significant role in determination of its usage. In coastal regions the situation becomes more complex due to the interplay of complex chemical processes like natural weathering, anthropogenic activities and sea water intrusion. Hence an attempt has been made in this study to delineate these processes and to identify the regions dominated by them. In this regard, 92 groundwater samples were collected and analysed for major cations and anions. Among the analysed parameters the ratios of the cations like Ca/Mg, (Ca + Mg)*/HCO3:(Na + K)*/HCO3 were used to identify the process of weathering. Moreover, the ternary plots of cations and selected anions were also used to identify the weathering and the anthropogenic processes. HCO3− and SiO2 in groundwater were used to unravel the nature of weathering, supported by pH and pCO2 observations. HCO3−-derived by the carbonate dissolution and silicate weathering were calculated from the total HCO3− and it was found that HCO3− derived from the carbonate rock dissolution is dominant in alluvium, tertiary and cretaceous formations due to the presence of kankar, calcareous sandstone and limestone. The (HCO3 + SiO2)/(Cl + NO3) ratios were used to demarcate the regions of weathering and anthropogenic activities and it was found that the central and north eastern part of the study area is dominated by the anthropogenic activities.

A study on the status of saltwater intrusion in the coastal hard rock aquifer of South India

Environment, Development and Sustainability, 2014

ABSTRACT Groundwater of the coastal regions represents a fragile environment. A study has been at... more ABSTRACT Groundwater of the coastal regions represents a fragile environment. A study has been attempted in the hard rock aquifer of the south-eastern part of India. A total of 135 groundwater samples were collected and analysed for major cations and anions. The domination of cations and anions was in the order of Na+ > Ca2+ > Mg2+ > K+ for cations and Cl− > HCO3 − > SO4 2− > H4SiO4 > NO3 − > PO4 − > F− in anions. The water is neutral to alkaline in nature with pH ranging from 6.30 to 9.20 with an average of 7.57. The ions analysed were used for standard plots, ratio of different ions and correlation between them helped to evaluate the active hydrogeochemical process and extent of saltwater intrusion in the coastal aquifer. The electrical conductivity (EC) contour shows that the groundwater quality is poor along the coast due to saltwater intrusion. The Piper and chadda’s plot shows that most of the groundwater samples fall on Na–Cl water type may be due to saltwater intrusion in the eastern part study area. The ratios of Cl−/HCO3 − ranged between 0.24 and 152.50 and have strong positive relationship with Cl− concentrations; it was found that about 30 % of the groundwater samples were strongly affected by the saline water in the study area. The Na+/Cl− ratios ranged from 0.20 to 3.73, and most of the groundwater samples fall close to the contamination region. Agricultural and salt pan land use pattern decrease the water quality due to impact of anthropogenic processes and seawater intrusion. Statistical analysis was also used to obtain the objectives, and it was found that the seawater intrusion is the major factor controlling the groundwater chemistry followed by other factors such as weathering and fertiliser impact.

Occurrence of the radionuclides in groundwater of crystalline hard rock regions of central Tamil Nadu, India

Journal of Radioanalytical and Nuclear Chemistry, 2014

A study was conducted to understand the occurrence of the radionuclides in groundwater of crystal... more A study was conducted to understand the occurrence of the radionuclides in groundwater of crystalline hard rock region. Samples were collected to analyze major cations, anions, U, 222Rn and stable isotopes of oxygen, hydrogen. It was inferred that few samples have U and 222Rn concentrations higher than the permissible limit of drinking water standard. High degree of weathering of granitic rocks and long contact time of groundwater with the aquifer matrix could be the reason for enhanced U and 222Rn levels in groundwater. The association of U with SO4 also proves that there exists anthropogenic influence in groundwater composition.

Study on the saturation index of the carbonates in the groundwater using WATEQ4F, in layered coastal aquifers of Pondicherry

Journal of the Geological Society of India, 2012

ABSTRACT A study was conducted to bring out the relationship and behavior of different Saturation... more ABSTRACT A study was conducted to bring out the relationship and behavior of different Saturation Index (SI) of carbonate minerals in layered coastal aquifers. Carbonates present in groundwater aids in different nature of the water like hardness, partial pressure of carbon-di-oxide (pCO2), pH and saturation index of different carbonate minerals at various temperatures. The SI of the carbonates helps us to define the thermodynamic stability of water and to find out the geochemical behavior of water. 98 groundwater samples were collected from specific aquifers (alluvium, upper Cuddalore, lower Cuddalore and Cretaceous) during Pre-Monsoon (May 2007) and Post-Monsoon (January 2008) seasons. The physicochemical parameters such as pH, EC, Ca, Mg, Na, K, Cl, HCO3, SO4 and PO4 were analyzed. Geochemical model, WATEQ4F was used to calculate the SI of different minerals. The SI was studied in relation to mHCO3 concentration, pCO2 and correlation between SI of different minerals.

Rare earth elements distribution in clay zones of sedimentary formation, Pondicherry, south India

Journal of Radioanalytical and Nuclear Chemistry, 2012

ABSTRACT Concentrations of five rare earth elements (REE) were measured in clay samples of a deep... more ABSTRACT Concentrations of five rare earth elements (REE) were measured in clay samples of a deep bore hole comprising major aquifers of Pondicherry region, south India in order to investigate the geochemical variations among various litho-units. Clay samples from Cretaceous formation show distinct gray to black color whereas Tertiary deposits have clays with color varying from pale yellow to brown to gray. All measured REEs exhibit lower concentrations than Upper Continental Crust (UCC) average values. Large variations in REEs contents were observed in different sedimentary formations (Tertiary and Cretaceous). Chondrite normalized ratio of La/Lu and Eu/Eu* indicate that the clays are derived from weathering of felsic rock and possibly under humid climate. All the samples showed positive Eu anomaly in North American Shale Composite (NASC) normalized plot which shows plagioclase feldspar as the major contributor to these clays. Positive Eu anomaly is also an indication of reduced condition of the formation.

Environmental Monitoring and Assessment, 2008

Drip water Geochemistry of Niah Great Cave, NW Borneo, Malaysia: a base line study

Carbonates and Evaporites, 2013

ABSTRACT A base line study was conducted to understand the geochemical variations of drip waters ... more ABSTRACT A base line study was conducted to understand the geochemical variations of drip waters in Niah Great Cave, Sarawak, NW Borneo of Malaysia. Drip waters were collected at three different sites within the cave (D6: SW entrance enroute to painted Cave; D5: centre of the Great Cave, and D8: west mouth Great Cave entrance). The collected samples were analysed for temperature, pH, EC, major elements, non purgeable organic carbon, d13C and d18O. Mg/Ca and Sr/Ca ratios, ionic strength, partial pressure of CO2 and saturation indices of carbonate minerals have been used to dictate the geochemical signatures of drip water compositions. The data reveal a wide range of major ion chemistry at three different sites within the cave. The d13C values in drip waters range from -10.58 to -10.09 %. The enriched and the depleted d13C values are noted at the entrances of the cave due to degassing of water CO2 and warmer air results in lighter fractions of d13C. The d18O values range from -6.89 to –6.16 %. Minor d18O deviation in the drip waters are due to the variation in drip rates as faster drip rates show depleted isotopic composition and vice versa. The spatial variability of drip water chemistry results due to water–rock interaction at various conditions of subsurface flow path. This study gives a basis for interpreting the varying controls on drip water chemistry in the cave.

Arabian Journal of Geosciences, 2012

A study on the interpretation of spontaneous potential and resistivity logs in layered aquifer sequence of Pondicherry Region, South India

Arabian Journal of Geosciences, 2013

ABSTRACT Geophysical logs provide a strong mechanism for interpretation and determination of the ... more ABSTRACT Geophysical logs provide a strong mechanism for interpretation and determination of the depositional environments, facies and also help in interpretations of hydrogeologic units. Spontaneous potential (SP) and resistivity logs can be used as an indicator of textural parameters. Pondicherry region has a complicated geology and with formation of different ages. The boreholes (BH) of this region are examined for litholog, SP and resistivity from four different BH locations, viz, Ariyankuppam, Chinnaverampattinam, Thavalakuppam and Nallavadu. These locations were studied and interpreted by using the shapes of the curves to identify the depositional environments, and this was later compared with the vertical litholog profile. Comparing the variation of these logs, the lateral variation of sedimentary facies was also attempted. The average resistivity values of Ariyankuppam, Chinnaverampattinam, Thavalakuppam and Nallavadu are 42.4, 30.4, 50.4 and 28.3 a"broken vertical bar m, respectively. Majority of the resistivity values corresponds from fine- to medium-grained sand, clayey pebbles, fine to very coarse sand and clayey sand with lignite. Frequency of resistivity values in each BH were identified for determining the dominant representative grain size. The study has pointed out the lithological variation of the system laterally and vertically using geophysical well logs.

Preliminary studies on the characterization of clay minerals in the Sundarban mangrove core sediments, West Bengal, India

Arabian Journal of Geosciences, 2012

Clay mineral found in rivers, estuaries, and marine sedimentary environments is an important grou... more Clay mineral found in rivers, estuaries, and marine sedimentary environments is an important group of minerals which is the by-product of chemical weathering. The main constituents of this fine-grained sediment include mudstones, clay stones, and shales. This is probably the first report of a Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) investigation on the clay minerals to characterize them in the Sundarban mangrove core sediments of Moipith Matla and Belamati Island. This study was carried out in the selected stretch for FTIR and SEM analyses. The study reveals the dominant association of kaolinite with subordinate amount of quartz, illite, and chlorite. The abundance of kaolinite, illite, chlorite, and clay with quartz helps in increasing the sediment in the island region. The geochemical and mineralogical evolution of mangrove sediment results in the interaction of biotic and abiotic parameters, whose balance is conditioned by the climate that governs the hydrologic regime, the sedimentation dynamics, and of the organic matter. This study on the characterization of clay provides substantial impact in the water-holding capacity, productivity, and mineralogical and chemical transformation in order to establish much more and intermediate equilibrium between marine influence and continental contribution, as a part of the estuarine environment.

Geophysical Investigation in the Different Litho Units of Gadilam River Basin, Tamil Nadu, India

Page 14. 1 Geophysical Investigation in the Different Litho Units of Gadilam River Basin, Tamil N... more Page 14. 1 Geophysical Investigation in the Different Litho Units of Gadilam River Basin, Tamil Nadu, India * PRASANNA MV 1, CHIDAMBARAM S. 2, NAGARAJAN R. 1 ... It is inferred as a faulted contact between the hard rock and the sedimentary formation (Aravindan et al., 2004 ...

The Tsunami Threat - Research and Technology, 2011

Variation of centennial precipitation patterns in Kuwait and their relation to climate change

Environmental Monitoring and Assessment

A new modified chloride mass balance approach based on aquifer hydraulic properties and other sources of chloride to assess rainfall recharge in brackish aquifers

Hydrological Processes

A reasonable estimation of aquifer recharge can assist in the sustainable management of groundwat... more A reasonable estimation of aquifer recharge can assist in the sustainable management of groundwater resources. The methodology to calculate aquifer recharge presents many challenges due to geological complexity and the existence of different water qualities in the aquifer. The classic chloride mass balance (CMB) method has been used widely for aquifer recharge estimation but the assumptions in the equations neglect other sources of chloride than rainfall; chloride accumulation due to evaporation and the hydraulic properties of the recharged aquifer. This research aims to introduce modifications and derive a new CMB equation that covers the shortcomings in the earlier classic CMB approach. The newly developed approach was verified mathematically to identify the sensitive parameters that affect the results of aquifer recharge. Also, it was verified by independent data and method (groundwater modelling) and showed that it is approaching reality about recharge estimation than the earlie...

Signatures of Dryas Groundwater in Stratified Aquifers of Kuwait-Paleoclimatic Significance

New Prospects in Environmental Geosciences and Hydrogeosciences, 2022

Environmental Earth Sciences, 2014

The present study aims to investigate the concentration and spatial distribution of trace metals ... more The present study aims to investigate the concentration and spatial distribution of trace metals in Tamirabarani river and estuary located in the southeast coast of India. Sediment samples collected from sixteen locations were analysed for Cu, Ni, Cr, Pb, Zn and Cd. The extent of pollution in these sediments was assessed using enrichment factor (EF), contamination factor (CF), geo-accumulation index (I geo ). The EF shows enrichment of Ni in the northern part of the estuary and that of Cu in the south and it is mainly due to the process of weathering. The contamination factor indicates Cd is more highly contaminated than other metals. I geo index shows that Cd is moderately polluted and its spatial distributions clearly indicate that it is found in estuarine region. The comparison of metal concentration with other estuaries of India indicates that these metals are well below the permissible limit. The metals in the estuary of the study area indicate more of the predominance of natural process than other estuaries in India. It is evident that the samples of river and estuary area are dominantly due to the natural process rather than anthropogenic activity.

Stable Isotopic Signatures for Hydrogeochemical Characterisation of Ground Water from Pondicherry to Nagapattinam, Tamil Nadu

Management of Water, Energy and Bio-resources in the Era of Climate Change: Emerging Issues and Challenges, 2014

Groundwater recharge is a critical hydrological parameter. Identification of recharge zones and r... more Groundwater recharge is a critical hydrological parameter. Identification of recharge zones and recharge estimates are essential to water resources management (Scanlon and Cook, 2002; Raju et al., 2006). In recent years, the overgrowing population and climate change are putting water resources under pressure all over the world. Sustainable management of aquifers to meet human and ecosystem needs will require protection of recharge areas and their augmentation (Reddy et al., 2000).

Online Journal of Earth Sciences, 2010

Hydrochemistry of groundwater from Tuticorin District, Tamil Nadu, India

ABSTRACT The study area being a hard rock terrain with minimal rainfall and large extraction of g... more ABSTRACT The study area being a hard rock terrain with minimal rainfall and large extraction of groundwater for domestic, irrigational and industrial purposes have threatened the groundwater environment both in the conditions of quality and quantity. Hence an attempt has been made to classify the major geochemical process activated for controlling the ground water chemistry. Groundwater was generally alkaline with higher EC values. The dominance of anions and cations were of the order of Cl->HCO3->SO4 2->H4SiO4>NO3->F-and Na + >Ca 2+ >Mg 2+ >K +. The plot for Na + /Cl-to EC indicates Na + released from silicate weathering and Cl-from anthropogenic activities. The plot for Ca 2+ +Mg 2+ to SO4 2-+ HCO3-, indicates ion exchange process. Thermodynamic plot indicates that groundwater is in equilibrium with kaolinite, muscovite and chloride minerals. In general, water chemistry is guided by complex weathering process, ion exchange. Saturation index of Carbonate and Sulphate minerals indicates under saturation to oversaturation and Silicate minerals were at equilibrium to oversaturation state.

Delineation of Natural and Anthropogenic Process Controlling Hydrogeochemistry of Layered Aquifer Sequence

Proceedings of the National Academy of Sciences, India Section A: Physical Sciences, 2014

ABSTRACT Groundwater is the source for many activities in urban regions and the quality plays a s... more ABSTRACT Groundwater is the source for many activities in urban regions and the quality plays a significant role in determination of its usage. In coastal regions the situation becomes more complex due to the interplay of complex chemical processes like natural weathering, anthropogenic activities and sea water intrusion. Hence an attempt has been made in this study to delineate these processes and to identify the regions dominated by them. In this regard, 92 groundwater samples were collected and analysed for major cations and anions. Among the analysed parameters the ratios of the cations like Ca/Mg, (Ca + Mg)*/HCO3:(Na + K)*/HCO3 were used to identify the process of weathering. Moreover, the ternary plots of cations and selected anions were also used to identify the weathering and the anthropogenic processes. HCO3− and SiO2 in groundwater were used to unravel the nature of weathering, supported by pH and pCO2 observations. HCO3−-derived by the carbonate dissolution and silicate weathering were calculated from the total HCO3− and it was found that HCO3− derived from the carbonate rock dissolution is dominant in alluvium, tertiary and cretaceous formations due to the presence of kankar, calcareous sandstone and limestone. The (HCO3 + SiO2)/(Cl + NO3) ratios were used to demarcate the regions of weathering and anthropogenic activities and it was found that the central and north eastern part of the study area is dominated by the anthropogenic activities.

A study on the status of saltwater intrusion in the coastal hard rock aquifer of South India

Environment, Development and Sustainability, 2014

ABSTRACT Groundwater of the coastal regions represents a fragile environment. A study has been at... more ABSTRACT Groundwater of the coastal regions represents a fragile environment. A study has been attempted in the hard rock aquifer of the south-eastern part of India. A total of 135 groundwater samples were collected and analysed for major cations and anions. The domination of cations and anions was in the order of Na+ > Ca2+ > Mg2+ > K+ for cations and Cl− > HCO3 − > SO4 2− > H4SiO4 > NO3 − > PO4 − > F− in anions. The water is neutral to alkaline in nature with pH ranging from 6.30 to 9.20 with an average of 7.57. The ions analysed were used for standard plots, ratio of different ions and correlation between them helped to evaluate the active hydrogeochemical process and extent of saltwater intrusion in the coastal aquifer. The electrical conductivity (EC) contour shows that the groundwater quality is poor along the coast due to saltwater intrusion. The Piper and chadda’s plot shows that most of the groundwater samples fall on Na–Cl water type may be due to saltwater intrusion in the eastern part study area. The ratios of Cl−/HCO3 − ranged between 0.24 and 152.50 and have strong positive relationship with Cl− concentrations; it was found that about 30 % of the groundwater samples were strongly affected by the saline water in the study area. The Na+/Cl− ratios ranged from 0.20 to 3.73, and most of the groundwater samples fall close to the contamination region. Agricultural and salt pan land use pattern decrease the water quality due to impact of anthropogenic processes and seawater intrusion. Statistical analysis was also used to obtain the objectives, and it was found that the seawater intrusion is the major factor controlling the groundwater chemistry followed by other factors such as weathering and fertiliser impact.

Occurrence of the radionuclides in groundwater of crystalline hard rock regions of central Tamil Nadu, India

Journal of Radioanalytical and Nuclear Chemistry, 2014

A study was conducted to understand the occurrence of the radionuclides in groundwater of crystal... more A study was conducted to understand the occurrence of the radionuclides in groundwater of crystalline hard rock region. Samples were collected to analyze major cations, anions, U, 222Rn and stable isotopes of oxygen, hydrogen. It was inferred that few samples have U and 222Rn concentrations higher than the permissible limit of drinking water standard. High degree of weathering of granitic rocks and long contact time of groundwater with the aquifer matrix could be the reason for enhanced U and 222Rn levels in groundwater. The association of U with SO4 also proves that there exists anthropogenic influence in groundwater composition.

Study on the saturation index of the carbonates in the groundwater using WATEQ4F, in layered coastal aquifers of Pondicherry

Journal of the Geological Society of India, 2012

ABSTRACT A study was conducted to bring out the relationship and behavior of different Saturation... more ABSTRACT A study was conducted to bring out the relationship and behavior of different Saturation Index (SI) of carbonate minerals in layered coastal aquifers. Carbonates present in groundwater aids in different nature of the water like hardness, partial pressure of carbon-di-oxide (pCO2), pH and saturation index of different carbonate minerals at various temperatures. The SI of the carbonates helps us to define the thermodynamic stability of water and to find out the geochemical behavior of water. 98 groundwater samples were collected from specific aquifers (alluvium, upper Cuddalore, lower Cuddalore and Cretaceous) during Pre-Monsoon (May 2007) and Post-Monsoon (January 2008) seasons. The physicochemical parameters such as pH, EC, Ca, Mg, Na, K, Cl, HCO3, SO4 and PO4 were analyzed. Geochemical model, WATEQ4F was used to calculate the SI of different minerals. The SI was studied in relation to mHCO3 concentration, pCO2 and correlation between SI of different minerals.

Rare earth elements distribution in clay zones of sedimentary formation, Pondicherry, south India

Journal of Radioanalytical and Nuclear Chemistry, 2012

ABSTRACT Concentrations of five rare earth elements (REE) were measured in clay samples of a deep... more ABSTRACT Concentrations of five rare earth elements (REE) were measured in clay samples of a deep bore hole comprising major aquifers of Pondicherry region, south India in order to investigate the geochemical variations among various litho-units. Clay samples from Cretaceous formation show distinct gray to black color whereas Tertiary deposits have clays with color varying from pale yellow to brown to gray. All measured REEs exhibit lower concentrations than Upper Continental Crust (UCC) average values. Large variations in REEs contents were observed in different sedimentary formations (Tertiary and Cretaceous). Chondrite normalized ratio of La/Lu and Eu/Eu* indicate that the clays are derived from weathering of felsic rock and possibly under humid climate. All the samples showed positive Eu anomaly in North American Shale Composite (NASC) normalized plot which shows plagioclase feldspar as the major contributor to these clays. Positive Eu anomaly is also an indication of reduced condition of the formation.

Environmental Monitoring and Assessment, 2008

Drip water Geochemistry of Niah Great Cave, NW Borneo, Malaysia: a base line study

Carbonates and Evaporites, 2013

ABSTRACT A base line study was conducted to understand the geochemical variations of drip waters ... more ABSTRACT A base line study was conducted to understand the geochemical variations of drip waters in Niah Great Cave, Sarawak, NW Borneo of Malaysia. Drip waters were collected at three different sites within the cave (D6: SW entrance enroute to painted Cave; D5: centre of the Great Cave, and D8: west mouth Great Cave entrance). The collected samples were analysed for temperature, pH, EC, major elements, non purgeable organic carbon, d13C and d18O. Mg/Ca and Sr/Ca ratios, ionic strength, partial pressure of CO2 and saturation indices of carbonate minerals have been used to dictate the geochemical signatures of drip water compositions. The data reveal a wide range of major ion chemistry at three different sites within the cave. The d13C values in drip waters range from -10.58 to -10.09 %. The enriched and the depleted d13C values are noted at the entrances of the cave due to degassing of water CO2 and warmer air results in lighter fractions of d13C. The d18O values range from -6.89 to –6.16 %. Minor d18O deviation in the drip waters are due to the variation in drip rates as faster drip rates show depleted isotopic composition and vice versa. The spatial variability of drip water chemistry results due to water–rock interaction at various conditions of subsurface flow path. This study gives a basis for interpreting the varying controls on drip water chemistry in the cave.

Arabian Journal of Geosciences, 2012

A study on the interpretation of spontaneous potential and resistivity logs in layered aquifer sequence of Pondicherry Region, South India

Arabian Journal of Geosciences, 2013

ABSTRACT Geophysical logs provide a strong mechanism for interpretation and determination of the ... more ABSTRACT Geophysical logs provide a strong mechanism for interpretation and determination of the depositional environments, facies and also help in interpretations of hydrogeologic units. Spontaneous potential (SP) and resistivity logs can be used as an indicator of textural parameters. Pondicherry region has a complicated geology and with formation of different ages. The boreholes (BH) of this region are examined for litholog, SP and resistivity from four different BH locations, viz, Ariyankuppam, Chinnaverampattinam, Thavalakuppam and Nallavadu. These locations were studied and interpreted by using the shapes of the curves to identify the depositional environments, and this was later compared with the vertical litholog profile. Comparing the variation of these logs, the lateral variation of sedimentary facies was also attempted. The average resistivity values of Ariyankuppam, Chinnaverampattinam, Thavalakuppam and Nallavadu are 42.4, 30.4, 50.4 and 28.3 a"broken vertical bar m, respectively. Majority of the resistivity values corresponds from fine- to medium-grained sand, clayey pebbles, fine to very coarse sand and clayey sand with lignite. Frequency of resistivity values in each BH were identified for determining the dominant representative grain size. The study has pointed out the lithological variation of the system laterally and vertically using geophysical well logs.

Preliminary studies on the characterization of clay minerals in the Sundarban mangrove core sediments, West Bengal, India

Arabian Journal of Geosciences, 2012

Clay mineral found in rivers, estuaries, and marine sedimentary environments is an important grou... more Clay mineral found in rivers, estuaries, and marine sedimentary environments is an important group of minerals which is the by-product of chemical weathering. The main constituents of this fine-grained sediment include mudstones, clay stones, and shales. This is probably the first report of a Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) investigation on the clay minerals to characterize them in the Sundarban mangrove core sediments of Moipith Matla and Belamati Island. This study was carried out in the selected stretch for FTIR and SEM analyses. The study reveals the dominant association of kaolinite with subordinate amount of quartz, illite, and chlorite. The abundance of kaolinite, illite, chlorite, and clay with quartz helps in increasing the sediment in the island region. The geochemical and mineralogical evolution of mangrove sediment results in the interaction of biotic and abiotic parameters, whose balance is conditioned by the climate that governs the hydrologic regime, the sedimentation dynamics, and of the organic matter. This study on the characterization of clay provides substantial impact in the water-holding capacity, productivity, and mineralogical and chemical transformation in order to establish much more and intermediate equilibrium between marine influence and continental contribution, as a part of the estuarine environment.

Geophysical Investigation in the Different Litho Units of Gadilam River Basin, Tamil Nadu, India

Page 14. 1 Geophysical Investigation in the Different Litho Units of Gadilam River Basin, Tamil N... more Page 14. 1 Geophysical Investigation in the Different Litho Units of Gadilam River Basin, Tamil Nadu, India * PRASANNA MV 1, CHIDAMBARAM S. 2, NAGARAJAN R. 1 ... It is inferred as a faulted contact between the hard rock and the sedimentary formation (Aravindan et al., 2004 ...

The Tsunami Threat - Research and Technology, 2011

Variation of centennial precipitation patterns in Kuwait and their relation to climate change

Environmental Monitoring and Assessment

A new modified chloride mass balance approach based on aquifer hydraulic properties and other sources of chloride to assess rainfall recharge in brackish aquifers

Hydrological Processes

A reasonable estimation of aquifer recharge can assist in the sustainable management of groundwat... more A reasonable estimation of aquifer recharge can assist in the sustainable management of groundwater resources. The methodology to calculate aquifer recharge presents many challenges due to geological complexity and the existence of different water qualities in the aquifer. The classic chloride mass balance (CMB) method has been used widely for aquifer recharge estimation but the assumptions in the equations neglect other sources of chloride than rainfall; chloride accumulation due to evaporation and the hydraulic properties of the recharged aquifer. This research aims to introduce modifications and derive a new CMB equation that covers the shortcomings in the earlier classic CMB approach. The newly developed approach was verified mathematically to identify the sensitive parameters that affect the results of aquifer recharge. Also, it was verified by independent data and method (groundwater modelling) and showed that it is approaching reality about recharge estimation than the earlie...