CHAP. XTI. 



Chiloe. 



393 



tions. In a straight line of cliffs, at Point Tenuy, I 

 examined the following remarkable section : — 



No. 35. 



Level of sea. 



On the left hand, the lower part (A A) consists of regular, 

 alternating strata of brown tuffs and greenish laminated 

 mudstone, gently inclined to the right, and conformably 

 covered by a mass (B left) of a white, tufaceous and 

 brecciolated deposit. On the right hand, the whole 

 cliff (B B right) consists of the same white tufaceous 

 matter, which on this side presents scarcely a trace of 

 stratification, but to the left becomes very gradually 

 and rather indistinctly divided into strata quite con- 

 formable with the underlying beds (A A) : moreover, a 

 few hundred yards farther to the left, where the surface 

 has been less denuded, the tufaceous strata (B left) are 

 conformably covered by another set of strata, like the 

 underlying ones (A A) of this section. In the middle 

 of the diagram, the beds (A A) are seen to be abruptly 

 cut off, and to abut against the tufaceous non-stratified 

 mass; but the line of junction has been accidentally 



