Vol. 63. .] KAISED BEACHES OF TALTAL. 65 



sea ; iii some places these boulders occur in well-defined lines of 

 ancient beach. At the present sea-level, boulder-beaches are 

 common, and form a striking feature of the coast-scenery. 



The width of this plain, and the altitude of its junction with the 

 foot-hills of the mountains, varies considerably ; behind the town of 

 Taltal it reaches to about 200 feet above sea-level. The strata dip 

 at a gentle angle towards the sea. The surface is thinly covered 

 with angular fragments of talus from the hills, while here and 

 there the subjacent massive rocks break through in curiously- 

 weathered remnants of former stacks and islets. Beyond a few 

 stunted cacti and desert-shrubs, the plain bears no vegetation, for 

 the formation is impregnated with saline substances. 



This inclined plain does not rise from the sea to the hills without 

 interruption. Evidences of alternating upheaval and quiescence 

 remain in lines and patches of shells, obliterated in many places and 

 becoming more obscure as the higher levels are reached ; sufficient 

 remains, however, to enable me to make out clearly three successive 

 terraces, and two other more obscurely, all of them containing, so 

 far as I am competent to judge, molluscan and other remains, in 

 every respect resembling those of the present sea. 



Measured along the same line of section, the edges or cliffs of the 

 main shell-beds are situated respectively at 15, 80, and 200 feet 

 above sea-level; I do not state these altitudes as more than approxi- 

 mations, since denudation has rendered their outlines very obscure. 

 The 'island' rock-masses contain in their hollows, and protected 

 under the talus of their summits, ' outliers' of the earlier terraces, 

 the main development of which is observed farther inland. 



In many places where no shell-beds now remain, further evidence 

 of former marine action is seen in a shelf of varying width cut 

 along the rocky coast, and also in a line of shallow caverns. A few 

 miles to the north of Taltal, at a place called Paso Malo, there are 

 two picturesque caverns of considerable size, excavated in igneous 

 rock : the mouth of one is now high above sea-level ; into the other 

 the waves rush at high tides over gigantic boulders, the haunt of 

 seals and sea-otters. 



At greater elevations than 200 feet the accumulations of shelly 

 matter tend to become more and more obscure ; for, although 

 calcareous masses occur at considerably-greater heights, I could 

 find no indication of their suspected organic origin, and these may 

 well be the surface-deposits of former springs. 



Shells of very ancient appearance are scattered at all elevations 

 and far inland, but these are almost certainly due to the habits of 

 the former Chango inhabitants and to shore-feeding birds. The 

 quantity of molluscs and echini eaten by the lower-class Chilians of 

 the present day is astonishing, and this must have been the case to 

 a much greater extent when such material formed the chief article 

 of food. The mysterious activity of the vanished natives is some- 

 times rather puzzling in its results. Thus, on oue occasion at 

 Taltal, I found a large and weathered block of comminuted shells 

 at the very summit of a hill 800 feet high. 



Q. J. G. S. No. 249. p 



