CHAP. 3.] GENEKAL FORMS OF SURFACE. 25 



forming aa irregularly branchiug ridge. Certain hard quartzose lines or 

 'ramj)s/ like 'blind lodes'^ are very numerous over the interior of the 

 country, always projecting above the surface of the adjacent rocks, 

 having better withstood the erosive agencies than these did. 



The belt of bedded traps which forms the range of hills nearest 

 to the sea, follows the rules observed by the other 



Traps. ■' 



strata, rising gradually with the southerly dip, in 

 some places forming antielinals which correspond with the outlines of 

 the ground, and presenting several well marked scarps and short slopes 

 on the out-crop of the beds. Alternations of softer and harder strata help 

 to pronounce these forms, though the rapidity with which the rocks 

 weather down sometimes tends to conceal the structure of the ground. 



Around the outer margin of these traps, is a band of variouslj^ 

 Outer foot of tlie trap colored soft rocks with some laterite and other 

 harder beds. They are frequently gjqjseous, and 

 occur sometimes as outlying patches and also in recesses of the traps. The 

 ground formed by them is always peculiar, if from the number and bril- 

 liancy of its colours alone ; and no other rocks in the district have forms 

 showing more strongly the wasting power of the weather. Eocks of 

 some solidity beneath are reduced upon the surface to powder, over which 

 the foot falls as lightly as if one trod on ashes. This in some places 

 seems to be the accumulated result of years of exposure to sun, dew and 

 wind ; and from such ground a single smart shower must remove an 

 enormous quantity of this disintegrated rock. 



The southern plains coincide with the tertiary rocks ; these from 

 the softness of then- natm-e and horizon tality of 



Tertiary plains. '' 



their undulating beds having doubtless favoured 

 the production of this form of ground. 



Wide depressions and somewhat elevated wold-like ti'acts also occur 

 with much rolling ground at the western extension of these rocks, the 

 same relations of hanging plane upon the ' dip' and more sudden slopes 

 d ( 25 ) 



