On the Occurrence of Welded Tuffs around Ingaldhal, Chitradurga, Karnataka, India

The note records the occurrence of nine different varieties of metavolcanic tuffs noticed around Ingaldhal such as breccia type, fine laminated type with graded bedding, laminated type with medium sized fragments, fine sericitised type with amygdales, devitrified glassy type, crystal tuff, ash flow type, brown sandstone type and type showing subparallel to radial structures. On the basis of the texture and structure exhibited by these rocks the possible mechanism of eruption is discussed. The relationship between sulphide mineralisation and tuff horizon has shown that structural control in ore localization is only of secondary importance at Ingaldhal.