METAMORPHIC SERIES. 33 



formation of a very considerable bank of calcareous tuff which is well 

 known to the people^ though the limestone rock. 



Calcareous tuff. 



as such, IS not. 



On the low plateau ground to the south of this position the lime- 

 stones, flung westward by the fault, reappear and are seemingly richer 

 and purer than they are at Olherpat. The following is the result of an 

 examination of a sample from this southex'n locality by Mr. Mallet :— « 



Carbonate of lime . . . . . . . . 91'9 



„ magnesia . . '2 



Oxide of iron and alumina '7 



Insoluble 7-2 



1000 



The small proportion of carbonate of magnesia and the purity in other 

 respects indicate a high value for this limestone as a flux for iron-smelting. 



The Hmestones are covered up on the west by Barakar grits and 



conglomerates, upon which too, in the neighbour- 

 Continuation of fault. 1 T n , J rr l -l • • 



hood 01 a stream, a tunaceous deposit is in process 

 of formation. The continuation of the fault is marked near the village 

 of Koorean by a ridge of fault rock which is surrounded on all sides by 

 Barakar beds, those on the north dipping away at high angles. This is 

 to be attributed rather to subsidence along the old line of fracture than 

 to the original fault, which, in all probability, operated before the deposi- 

 tion of the Barakars. 



Had it taken place subsequently, its effects, considering the fling it 

 has certainly given to the limestones, should be distinctly traceable in 

 the distortion of the ironstones and carbonaceous shales beyond Lejang, 

 but no such distortion is to be seen. 



Along the eastern margin of the field the bounding rocks are chiefly 

 granitic gneisses with veins of quartz and pegmatite. Inside the 

 margin a small inlier of these rocks is exposed one mile north-west of 



» This is shewn by the name of the village, which is derived from chuna (limo). 



c ( 33 ) 



