GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 539 



Oligocene — Continued. Feet thick. 



5. Friable, lignitic shale bed 2 



4. Light-gray, limy-looking clay bed with some limy 

 nodules and some lenses of soft nodular clayey 



limestone 6 



3. Friable, lignitic shale bed 2 



2. Light-gray to greenish fine-grained clay and fine 



agglomerate. Fairly massive 7 



Unconformity. 



Eocene? 



Las Cascadas agglomerate : 



1. Dark-gray volcanic agglomerate 50 



Total thickness 275 



Section in cuttings of Panama Railroad near Caimito Junction. 



Oligocene: 



Emperador limestone — 



Feet thick. 

 6021 and 6673-4. Light-gray to cream-colored, sandy lime- 

 stone, Lepidocyclina vaughani abundant, 

 also anullipore (Lithothammiumisthmi) and 

 numerous fragments of echinoid tests, in- 

 cluding a Clypeaster (?). Strike N. 30° E., 

 dip 20° N. 60° W About.. 70 



Unconformity. 

 Bohio conglomerate — 



3. Fine argillaceous conglomerate; small pebble beds 

 with sandy matrix, separated by clayey and sandy 



layers 20 



2. Conglomerate, with gravel, cobbles, and small boul- 

 ders; matrix clayey and sandy; fairly well bedded. 

 Cobbles and boulders are mostly hornblende ande- 

 site and diorite 20 



Unconformity. 



Eocene (?) (Las Cascadas agglomerate): 



1. Dark, massive, hard, and fairly well cemented andesitic 



agglomerate. Contains subangular fragments of andesite 



and basalt from a foot or more to less than an inch in 



diameter. Matrix fine dark andesite tuff. 



United States National Museum locality record station 6022 is 



on limestone about the same as (4), described above, a mile 



farther north. 



Railroad cut near stream about midway between Rio Frijol and Rio Frijolito. 



Oligocene (Culebra formation): Feet thick. 



2. Surficial, residual red clay 15 



6023. 1. Dark, very basic, friable, tufaceous material; Lepi- 

 docyclina canellei very abundant About. . 25 



