4 WALKER : GEOLOGY OF KALAKANDI STATE. 



probable that they do not represent a geological unit as they include 

 both metamorphosed igneous rocks — ortho-schists — and metamor- 

 phosed sediments or para-schists. In mapping the crystalline schists in 

 four groups, it must be understood that the boundaries indicated are 

 only approximate. This is due to several reasons, the two chief being 

 that the time spent on the work was too short for detailed mapping 

 even if the forest growth and the alluvial covering permitted it, and to 

 the well-known fact that members of a crystalline complex are often so 

 closely related as to origin and subsequent history — genetically and 

 metamorphically — that they pass gradually and imperceptibly into one 

 another, and sharp and definite boundaries do not really exist. 

 Examples of this will be cited in the geology of Kalahandi state in the 

 following pages. 



The rocks of the Schist Complex occupy the western part of the 

 state. To the west they are almost identical with those described in 

 Nawrangapur in the first part of the present report. They occupy 

 the whole of the 800- foot plain east to the edge of the 3,000-foot 

 plateau and as far north as Lat. 19 47' from which point they are 

 bounded on the east by the Granitoid Gneiss. 



The chief rock of this complex is a pink fairly felspathic biotite 

 gneiss with hornblende and frequently monoclinic pyroxene (speci- 

 mens I5'i43, 15*144 and 15' 148). Usually the rock is distinctly 

 foliated or banded and strikes about north-north-west, but this is not 

 always the case. Subordinate bands of mica schist, amphibolite and 

 quartzite occur. The gneiss is very probably an intrusive granite 

 banded by movement in the solidifying magma and subsequently 

 foliated. It is much more felspathic than is usual in the case of para- 

 schists. 



Near Chachanbali I observed these gneisses in contact with slates of 

 the Cuddapah system, which were flecked and knotted near the contact 

 as if they had been acted upon by an igneous intrusion. Though 

 typical contact minerals such as cordierite and andalusite were not 

 observed, the general megascopic appearance of these peculiar slates 

 is certainly such as to suggest contact metamorphism. This would 



