DISCOVERY OF THE CAPE FAIRWEATHER BEDS. 67 



of marine sandstones some thirty feet in thickness, from which the block 

 first observed lying on the beach had been derived. It was impossible to 

 determine the exact stratigraphic position of the marine deposit from an 

 examination of the top of the landslide. On turning my attention to the 

 cliff above me, however, numerous large oyster shells appeared mingled 

 with the sands and clays of the talus, while lying at the extreme top of 

 the cliff, but beneath the shingle, the thirty feet of marine sandstones 

 were clearly visible, as shown in Fig. 3. Here was a new discovery 

 full of interest and meaning. The presence of these marine deposits 

 overlying the several hundred feet of fresh-water and seolian deposits con- 

 stituting the Santa Cruz beds, means that subsequent to the times when 

 Nesodon, Astrapothermm, Icochilns, T/ieosodon, Diadiaphorus, Boryhycena, 

 Phororhacos, and numerous other genera of animals lived about the 

 borders and left their bones to be buried in the mud then forming at the 

 bottom and along the shores of the prehistoric streams, rivers and lakes 

 of the Santa Cruzian epoch, this entire region had been buried beneath 

 the ocean for the time during which these marine beds were deposited. 

 I subsequently observed these new marine deposits, which I have called 

 the Cape Fairweather beds, at various other and widely separated locali- 

 ties, and there is little doubt that they at one time covered all southern 

 Patagonia, though at present they are wanting over large areas, having 

 been removed by erosion. In the foothills of the Andes I found them 

 capping the mountains at altitudes of five thousand feet or more, thus 

 demonstrating what an enormous movement the crust of the earth has 

 undergone over this region since their deposition in the Pliocene seas. 



The top of this landslide, from which was made the interesting discovery 

 detailed above, was capital collecting ground. Not only were we able to 

 secure a very complete series of the marine invertebrates belonging in 

 the beds at the summit from the blocks of matrix that had tumbled down, 

 but the narrow and irregular valley which lay between the face of the 

 cliff and the front of the landslide was covered over with calafate, mate 

 verde and mate negra bushes which, on account of the peculiar protection 

 the location afforded them, attained a size considerably exceeding that 

 of the same bushes on the wind-swept plain above. For this reason this 

 cozy corner was the favorite haunt of many birds and small mammals. 

 In the midst of the dense foliage of the mate negra the little brown wren, 

 Troglodytes hornensis, sends forth a perpetual chirrup. Constantly on 



