Fknton — Recent Pampa and other- Formations in Patagonia. 603 



northern side by the Gallegos River, and on the southern by a cafiadon (D), 

 known as the Cafiadon of the Buitreraa, which is about a quarter of a mile 

 broad, and which separates C from a high basaltic table E, extending 

 away indefinitely to the south. It was on the floor of this cafiadon, bounding 

 the south side by table C, that the writer first came across typically striated 

 stones, showing that ice -action had been at work. The striated stones were 

 large fragments of basaltic rock up to a yard or more in length •; they lay on 

 the bottom of the cafiadon D, and exhibited well-marked striation, all the 

 striae running parallel with the line of the cafiadon. 



Nothing of the nature of terminal moraines could be seen at the outlet of 

 this cafiadon, which appears extraordinary, unless they have long since been 

 buried under recent pampa dust. 



Now, although, as we have said, there are not terminal moraines opposite 

 the end of cafiadon D in Plate XLVII, fig. 3, nor in fact in any place between 

 that and the mouth of the Gallegos River, some forty miles away, yet there are 

 numerous large erratic boulders to be found in certain parts of the pampas. 



On leaving the lower reaches of the River Gallegos, and travelling to the 

 south over the pampas in the direction of the straits of Magellan, when one 

 has gone about ten miles on the road, large solitary stones begin to appear, 

 some of these weighing many tons, and all of them lying right on the surface 

 of the pampa. They are not basaltic, but more of a granitic or schistose 

 nature, and are, as a rule, well rounded, showing that they have been exposed 

 to the weather for long periods ; they seem to extend indefinitely towards the 

 south. Eight through the region where these large erratics are found there are 

 numerous traces of volcanic outbursts, such as are seen in Plate XLVII, fig. 3, 

 which shows a lava-flow over the surface of the pampa, coming from a crater 

 at the back. Now, no basaltic erratics are found in any portion of the pampa, 

 which shows that the volcanic outbursts must have occurred since the period 

 when the large erratics were transported to their present positions. These 

 erratics, as I have said, are found all the way down to the Straits of Magellan ; 

 they are not found to the north of the lower reaches of the Gallegos River, nor 

 do they reach that river near its mouth. On the other hand, when one goes 

 further west about seventy miles, these same large erratics are found across 

 the river to the north, and on the highest summits of the pampas and 

 hills, and even reach as far north as the upper portion of the River Ooyle. 

 These erratics are also found congregated in numbers in the valley of the 

 River Gallegos further to the west, and down to seventy miles from the mouth, 

 and give the appearance of having been brought together there by ice ; 

 but it is more likely that they simply rolled into their present position in the 

 valley from the high pampas on either side as tlie valley was cut down, since 



