BLACK GALAXY GRANITE IN CHIMAKURTHY ONGOLE, IN PRAKASAM DISTRICT.
Prakasam district has come into prominence as a granite producing district in the State in recent years, thanks to the discovery of what is known as “Galaxy Granite” in the Chimakurthy area of the District; this unique type won international recognition. The granite bearing areas in the district can be divided geologically into parts, the southern part falling in the mica-schist belt and the northern part forming a part of the granite terrain (Statement-5).
Black granite deposits around Chimakurthy basically are anorthosite gabbro pyroxenites which have intruded into biotite-hornblende scheme. The rocks are of black colour and medium grained and take good polish. Some places near Chimakurthy and R.L.Puram, the anorthosite gabro-pyroxenite has developed crystal of bronzite (a pyroxene which is golden yellow in colour). The golden yellow crystal stuffed sky, hence the name Galaxy granite. This variety is being quarried around Chimakurthy and R.L.Puram whereas the black gabboric-pyroxenite is being quarried near Budavada.
Good deposits of coloured granites occur around Uppumangaluru and Kodidena. These are mainly hypers thene granites which form extensive hillocks; and these are being worked. Apart from this, syenites from Elchur are also being quarried as dimensional stones.
GRANITE OCCURRENCES IN MARKAPUR – PRAKASAM DISTRICT
Geologically the area belongs to Dharwar Super Group and the associated intrusive of Archean age. Migmatites, Pyroxene-anorthosite-gabbro complexes and veins of quartz and pegmatites represent the region. Gabbro norite is emplaced in the granites. The subjected area falls on the Gabbro Norite body. The gabbro norite is mesocratic medium gray in colour and coarse grained consisting dominantly of plagioclase and hypersthene with subordinate quantity of augite. The rock shows intergranular texture.
LOCATION: MARKAPUR ZONE
|QUARRY VILLAGE||MANDAL||COLOUR GRANITE|
SLATE OCCURRENCES IN MARKAPUR DISTRICT
Geologically the area belongs to Cumbum Formation of Nallamalai series of Kadapa Super Group. The Cumbum Formation conformably over lies the Bairenkonda Formation and it includes Slate, Shaly Slates, Quartzites and Shale with Quartzite intercalation. The argillaceous sediments have been transformed into slates by high-grade regional metamorphism and it is involving changes in both temperature and pressure. The clay minerals were recrystallised by continued metamorphism. Increasing in the grade of metamorphism give rise to schistosity with the deelopment of slaty cleavage in Nallamalai fold belt and the slates occurring in the area are variegated colours with different designs. The Slate Belt in Prakasam District is having NE-SW direction with vertical or sub-vertical dips towards East and extends over a length of 40 KM between Chinnaobinenipalli in South and Mallampeta in North.
The colour of the slate tends to reflect the quantity of organic matter present and most particularly the Oxidation State of the iron. The slates are coloured light grey with pink spots, pink, pinkish grey with different designs and the colour changes to light grey, reddish grey and yellowish grey from place to place in the area. Being the variegated colours, development of fissility for required thickness and acquired of big slabs, most of the material available here is being consumed for building purpose as decorative stone like flooring, roofing and wall paneling. Here 95% of excavated slate material is being used in decorative slates and remaining is being used in manufacture of writing slates.
BLACK GALAXY GRANITE OCCURRENCES IN CHIMAKURTHY ,PRAKASAM DISTRICT
|QUARRY VILLAGE||MANDAL||GRANITE COLOUR|
|Budavada||BLACK GALAXY GRANITE|
|R.L.Puram||BLACK GALAXY GRANITE|