OLD SEA MARGINS 35 



indications of ocean work at higher level is, indeed, about 

 the last distinct step in geological inquiry. 



At many points 'where the elevation of the land has 

 recently occurred, as it often has in some slight measure 

 since the beginning of recorded history, it is very easy to 

 note the traces indicating the recent presence of the sea. 

 There is the cliff, against which the waves broke, often with 

 its accompanying caves, and chasms, and the beach slope 

 frequently retains the semblance of its original character. 

 But even in these monuments of sea-action, which may not 

 be older than the Pyramids, the student observes that the 

 change-bringing forces have often worked with such efficiency 

 as in good part to destroy, or at least to confuse, the evidence. 

 A talus has generally formed at the foot of the steep, whicli, 

 with the falling in of the cavern roofs and the chasm 

 sides, has greatly modified the form of the strata. At the 

 same time, the streams cutting through the beach line, have 

 washed the friable materials to and fro so that the original 

 regularity of the feature has been in good part lost. Observ- 

 ing this rapid destruction of the marine monuments which are 

 so conspicuously in evidence along the existing shore line, the 

 student is prepared to find the indices of higher, and, therefore, 

 more ancient shores become progressively and rapid]\- less 

 clear as he ascends above the existing coast line. His antici- 

 pations will be more than realized, for he will find that the 

 task of tracing sea margins of considerable elevation is one of 

 surprising difficulties. He has, in fact, to trust rather to bits 

 of evidence than to a massive presentation of the truth. He 

 will not find the old borders of the land marked as he might 

 expect them to be, by long straight benches, but rather by 

 fragments of the ancient shelves with here and there, perhaps, 



