GEOLOGY OF THE AREA. 15 



The quartzo-hornblendic gneiss with the crystals arranged with 

 their axes parallel to one another can hardly be said to belong to any 

 one of the three great groups, for it may be found anywhere. The 

 best examples are found to the north of Manjeri and to the north of 

 Pandikad. 



Intrusive rocks. 



All the intrusive rocks of this area being pre-lateritic, it will be 

 convenient to describe them next. 



Some of the highly hornblendic rocks already mentioned are prob- 

 ably eruptive, and this may be the case also with the bands of 

 quartzo-hornblendic gneiss north of Manjeri and Pandikad. But 

 besides these there are some undoubted dykes which are of consider- 

 able length, though much concealed by laterite. 



The most remarkable is one which forms a conspicuous ridge just 

 south of Pandalur Hill. It runs to the south-east, crossing the Anga- 

 dipuram-Mandrkcid road about half a mile east of Perintalmanna. 

 Near Cherpalcheri it is again well seen forming a high ridge which 

 touches the west side of the high conical hill two miles south-west of 

 the village. It still continues its south-easterly course and is found 

 about two miles north-west of Watapalam. This dyke is composed 

 of white felspar, hornblende, and magnetite. The magnetite is very 

 abundant, and with the hornblende forms little nests in the felspar. 

 At Angddipuram the sides of the dyke are compact, and the middle is 

 crystalline as just described. This is also the case in other places, the 

 borders of the dyke being sometimes almost felsitic in structure. A 

 small dyke of this felsitic rock is found on the road from Manjeri to 

 Malapuram, about two miles from Manjeri. This is not exactly in 

 the line of the big dyke, so that perhaps it is only an offshoot from it. 



The other dykes consist of a very different rock. They are com- 

 posed of felspar and augite ; the augite forming ophitic masses. On 

 a line running just east of Manjeri, in a direction from 67 N. of W. 

 to 67 S. of E., several exposures of trap are seen. The most northerly 

 is about a mile east of Wakalur on the Beypore River. The direc- 

 tion of the dyke here, however, is 15 S. of E., so that if it is con- 



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