Volume : 8, Issue : 2, February - 2019

DIFFERENT GEO-TECTONIC OCCURRENCE OF QUARTZ FELDSPAR PORPHYRY IN THE KADIRI TALUK OF ANANTAPUR DISTRICT, ANDHRA PRADESH, INDIA

R. Maheswararao. , S. Srinivasa Gowd, G. Harish Vijay

Abstract :

Quartz Feldspar Porphyry is a rock type that has special status in the classification of rocks. It has the distinction of occurring as volcanic, hypabyssal and also as volcaniclast. The Kadiri taluk has hosted this special rock type in the form hypabyssal and also as volcaniclast within a distance of 40km. The volcaniclasts occur as a lithounit in the Kadiri Greenstone belt. The clast size gets decreased from east to west pointing to the younging direction. It has opalescent quartz reflecting the volcanic origin. It reflects some sedimentary features like cross bedding, cut and fill structures etc. The hypabyssal nature of the Quartz Feldspar Porphyry occurs as an intrusive into the granitoid country and it is located near Namala Gudi (temple), on way to Kadiri from Pulivendla. It runs for about 6-8km in the NNE-SSW direction. It has porphyroclasts of quartz and feldspar set in a fine grained matrix of the same material. The differences in the setup of this special type of rock are highlighted.