International Journal of Earth Sciences and Engineering

S. Manjunatha ¹, Raju Sukhaye ¹, G. S. Pujar ¹, B. Chandan Kumar ²

Affiliations
1 Department of Geology, Karnatak Science College, Dharwad-580001, IN
2 Department of Studies in Geology, Karnatak University, Dharwad-580003, IN

Abstract

The Proterozoic clastic sediments exposed at Naragund, Karnataka belongs to the Kaladgi Group, which are unconformably under lain (Eparchean unconformity) and surrounded by Archaean gneiss. The rocks are characteristically bedded with individual beds having variable thickness. Based on the color variation, four varieties of quartz arenite have been distinguished as the grey, white, red and pink quartz arenites. The primary sedimentary structure like stratification, ripple marks, current bedding and graded bedding are commonly seen in the study area. The petrographic analysis has revealed that the clastic sediments are quartz-rich and were primarily derived from felsic sources. The chemical composition of 10 quartz arenite samples corroborates the petrographic observations. The provenance and geodynamic studies indicate that the clastic sediments were derived predominantly from felsic source region and were deposited in a passive margin type tectonic setting.

Keywords

Clastic Sediments, Petrography, Geochemistry, Quartz Arenites, Provenance, Tectonic Setting.

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S. Manjunatha ¹, Raju Sukhaye ¹, J. Davithuraj ²

Affiliations
1 Department of Geology, Karnatak Science College, Dharwad-580001, IN
2 CGWB, SUO, Belgaum-590019, IN

Abstract

The physico-chemical characteristics of groundwater in the state of Goa have been studied to assess the quality of groundwater and its suitability for domestic and irrigation purposes. Groundwater samples from shallow aquifers (38) and from deep aquifers (39) were collected in the year 2014. The groundwater samples were analyzed for various physico-chemical parameters (pH, TDS, TH, Ca⁺⁺, Mg⁺⁺, Na⁺, K⁺, HCO₃^-, CO₃^--, CI^-, SO4^--, N0₃^-, F^-). Assessment of groundwater samples from various methods indicated that groundwater in the State of Goa is chemically suitable for drinking and Irrigation purposes. Major cations and anions were plotted in Piper diagram to evaluate the hydrochemistry of groundwater of the state of Goa. The plot shows that most of the samples from shallow aquifers fall in strong acids exceeds weak acids followed by carbonate hardness exceeds 50% and from deeper aquifers fall in weak acids (CO₃^--+HCO₃^-) exceed strong acids (SO₄^--+Cl^-) followed by alkalies exceeding alkaline earths.

Keywords

Hydrochemical Facies, Assessment, Groundwater, Drinking Purpose, Goa, India.

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K. N. Prakash Narasimha ¹, R. Vishwanath ¹, B. V. Suresh Kumar ¹, S. Manjunatha ²

Affiliations
1 Department of Studies in Earth Science, University of Mysore, Manasagangotri, Mysore-570006, IN
2 Department of Studies in Geology, Karnatak Science College, Dharwad, Karnataka, IN

Abstract

The vermiculite in its macroscopic form occurs associated with the mafic rocks in the vicinity of the acidic intrusions around Ajjampalli area in the Kolar schist belt in south India. Mafic rocks form part of the ancient supracrustals and belong to Sakarsanahalli association in the Kolar schist belt of Eastern Dharwar craton. The study area is covered in the Survey of India toposheet 57L/1 and lies between the 12⁰58’ latitude and 78⁰14’ longitude. The present study forms the first detailed investigation of the occurrence of the macroscopic vermiculites in the Ajjampalli area in Kolar schist belt. The study involves field and Petrographic features linked with the mineral chemistry aspects to understand the genesis of vermiculites. XRD, TGA and FTIR techniques have been used to characterize the vermiculites of the study area. The formation of vermiculite in the study area is attributed to the hypogene process followed by epigene process through an intermediate stage of hydrobiotite.

Keywords

Vermiculites, Kolar Schist Belt, Eastern Dharwar Craton, Hydrobiotite.

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