14 WALKER : GEOLOGY OF KALAHANDI STATE. 



IX.-DYKE ROCKS. 



I have seen very few rocks of this class in Kalahandi state. West 

 of IKutragas near Tuamal-Rampur I observed a garnetiferousepidiorite, 

 apparently a dyke rock, and in a stream bed near Kuropodar a black 

 heavy rock consisting of plagioclase, colorless monoclinic pyroxene 

 and very pleocloric brown biotite, forms a well-defined dyke. The 

 former rock is very probably derived from the alteration of a gabbro 

 of some kind. 



It may be well to note the unusual poverty of dyke rocks in the 

 whole of the northern end cf the eastern Ghauts. In the adjoining 

 district of Gangam and Vizagapatam this property has been previously 

 observed. Freedom from violent earth movements over this region 

 for a long period may be suggested as the explanation. 



X.-ECONOMIC GEOLOGY. 



(0.— Graphite. 



In studying the geology of the Ganjam Malias Mr. Smith of this 

 department observed that one of the chief schists — the Khondalite 

 of this report — almost always contains graphite in the form of flakes 

 and scales. The principal minerals of this schist were found to be 

 quartz garnet and siilimanite. Rocks of this type have also been 

 observed along the eastern border of the eastern Ghauts near Sunki 

 and Chotua in Vizagapatam and also as already indicated in many 

 parts of the Kalahandi state. Graphite, though generally disseminated 

 through these schists, has never been found in them in economic 

 quantities either in Kalahandi or in the adjoining districts in the 

 Madras Presidency. 



In the Kalahandi state graphite is known to occur as veins or nests 

 in several parts, not in the Khondalites but never very far off from 

 outcrops of these schists. Some of these graphite deposits appears to 



