66 PATAGONIAN EXPEDITIONS : NARRATIVE. 



work in behalf of natural history had been in connection with vertebrate 

 palaeontology. 



After several days spent in much the same manner and with success 

 very similar to that of the day just described, I decided to spend a por- 

 tion of my time in exploring the bluffs of the sea to the northward from 

 Cape Fairweather in search of fossils. For some days I searched these 

 beds, but with only very indifferent success. While walking along the beach 

 on the morning of a particularly fine winter's day, for Patagonia, in July, 

 while we were still camped at Cape Fairweather, I noticed a great block 

 of hard sandstone weighing several tons lying at the base of the cliff, half 

 buried in sand and literally covered with the fossil shells of gasteropods, 

 brachiopods, giant oysters and other marine invertebrates. I was not a 

 little astonished at this, for I had carefully noted the character of the rocks 

 composing the bluffs as I walked along and had determined them to be- 

 long to the Santa Cruzian formation and of fresh-water origin, and no 

 marine beds had ever been reported as overlying these deposits. From 

 whence then came this great mass of sandstone, so clearly of marine 

 origin ? Its very size, as well as its sharp angles and unpolished surfaces, 

 precluded its having been transported from a distance. On looking 

 about I saw another smaller but similar block only a few feet above my 

 head protuding from the talus which had here accumulated at the foot of 

 the cliff. From this I traced the origin of this marine deposit still higher, 

 until, at an elevation of some two hundred feet, I gained the top of a great 

 land slide, where a tract about half a mile in length and from one to two 

 hundred yards in width had broken away from the main mass and slid 

 off into the sea, carrying with it a section of the plain above equal to the 

 dimensions just given. In its slide downward, the bottom of the mass 

 had evidently moved a much greater distance seaward than the top, so 

 that the latter was left behind, as it were, and thrown backward, causing 

 the different strata and what had once been the surface of the plain to be 

 inclined at a high angle dipping downward and backward toward the face 

 of the cliff, while the upper surface of the slide presented a very broken 

 and uneven appearance, bearing abundant evidence as to the great dis- 

 turbance which had taken place in its strata at the time of its displace- 

 ment. Where not covered with talus, which had accumulated in great 

 quantities at the foot of the cliff that still towered two hundred and fifty 

 feet above, I detected in the upturned edges of this landslide a stratum 



