976 REPORT OF NATIONAL MUSEUM, 1895. 



"The oest exposures of the lower beds were found between Canoas 

 and Bluff points [Plate 1,] where they present perpendicular bluffs, 

 facing the sea, from a few hundred up to nearly a thousand feet in 

 height. These are being rapidly undermined and eaten back by the 

 action of the waves, so that between the two points the coast line forms 

 a bow-like reentering curve, set back 3 to 5 miles from a line drawn 

 between the points. From either point the land lises in a series of 

 steps or broken terraces to an extensive plateau, cut on the sea faces 

 by short, narrow, branching ravines aud presenting in general contin- 

 uous bluff faces inland. 



"Midway in the reentering curve between Canoas and Bluff points is 

 the Playa Santa Caterina, where is a gap a mile or two in width between 

 the bluffs bordering the ocean, formed by a broad valley in which are 

 two modern stream beds draining the interior region. They are divided 

 at the shore line by a flat-topped ridge of Chico beds, near the top of 

 which is the remnant of an ancient stream bed whose bottom is now 

 about 100 feet above tide water, and which is filled by a conglomerate 

 of large bowlders aud water- worn pebbles of massive rocks. This con- 

 glomerate, which is cemented by lime and iron, is so much more resist- 

 ing than the soft clays of the Chico formation that the huge bowlders 

 that fall as the cliff is undermined by wave action form a point pro- 

 jecting out several hundred feet beyond the average coast line. These 

 conglomerates are probably of the same age as those which are found 

 at various points in the canyons of the interior, and their formation 

 evidently dates back to a time when, after the carving out of the gen- 

 eral system of modern drainage, the waters of the ocean reached a 

 higher level than the present, and the old drainage channels were par- 

 tially filled up to the then base level. Subsequent erosion, while cut- 

 ting down to a somewhat lower level and following the same general 

 lines, has often eaten more readily into the softer beds at the sides of 

 these recent conglomerates and left patches of them still standing, 

 which sometimes form one wall of the canyon a hundred or more feet 

 above its present bottom. 



"The modern stream beds from Playa Santa Caterina are almost at 

 base level for some 10 miles inland, at about which distance eruptive 

 rocks appear from under the Cretaceous and recent beds, and then rise 

 rapidly, reaching an elevation of about 1,500 feet within 15 miles of the 

 coast, on the partly buried slopes of the coast range. 



"Both in the broad valley and on the mesa slopes are relics of terraces 

 which evidence a successive rising of the land above the ocean. 



"The lower beds exposed in the bluffs along the coast have a gentle 

 inclination northward and southward from Sandstone Point, about 3 

 miles north of Playa Santa Caterina, where massive sandstones form a 

 slightly projecting headland. In these sandstones carbonized plant 

 remains, too indefinite for identification, were found, and in the cracks of 

 the immediately overlying sandy clays were traces of petroleum. From 



