534 BULLETIN - 103, UNITED STATES NATIONAL MUSEUM. 



Eocene — Continued . 



the fault line springs bubble up, the "waters from which were 

 saline and astringent and gave off much carbon dioxide. 

 This locality is now covered by the water in the canal. 



Section, north end of Miraflores Locks. 



Oligocene (Culebra formation): 



At the north end of Miraflores Locks and from there to Pedro 

 Miguel Locks, beds belonging in the lower part of the Cule- 

 bra formation outcropped in the canal cut. They consist 

 of dark, well laminated, and very soft carbonaceous clay 

 rocks, and locally contain lenses of granular tufaceous 

 material and a few beds that carry some pebbles. Some 

 lines of small concretions parallel to the bedding were 

 noted. Foraminifera common. In general, the beds have 

 a dip of a few degrees toward the south, although one south- 

 ward dip of 25 degrees was noted. 



Section, Pedro Miguel Locks to Paraiso Bridge. 



Oligocene (Culebra formation (lower part)): 



6010. Material the same as in the preceding exposure. Ostrea, 

 Pecten, and many Foraminifera,in eluding Lepidocyclina 

 panamensis?, were collected. 



Section at Bald Hill near Miraflores Locks. 



Total thickness of exposure about 325 feet; dip of beds 15° NW. 

 Oligocene : 



Caimito formation — Feet #"<*• 

 5. Limy, fine-grained sandstone, which weathers slightly 

 buff-colored. A few fragments of fossils noted; out- 

 crop indistinct. Estimated 60+ 



4. Dull yellowish, buff after weathering, rather soft and 

 somewhat massively bedded, fine-grained sandstone. 



Estimated 80+ 



3. Limy agglomerate beds, light colored to brown, with a 

 few greenish stains, similar to the blue and green 

 stained beds that outcrop near San Pablo. Middle 



member of the Caimito formation. Estimated 65+ 



2. Light yellow to buff after weathering, fine-grained 

 sandstone, fairly thick-bedded, but weathers rather 

 platy or somewhat spherical. Lower part of the 

 sandstone seems to be rather limy and weathers 

 easily. Lower member of the Caimito formation. 



Estimated 80+ 



(There is some evidence of an unconformity between (2) 

 and (1), but the contact is not clear enough to be 

 sure of this.) 

 Emperador limestone — 



6256-1. White to creamy gray, rather pure limestone; 

 weathered surface much pitted; contains many 

 fossil corals. Typical Emperador limestone. 

 Estimated 40+ 



