46 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



601%. — Oligocene — Culebra formation. 



From section — west side of Gaillard Cut. 



a. Dark, well laminated soft and very friable carbonaceous shale. 



Few foraminifera — some glauconitic, others well preserved. 



c. From a lens of sandy limestone 5 feet thick. 



Few foraminifera — some stained, some glauconitic, rather poorly 

 preserved as to details. 



d. From lenses of limy sandstone at base of gravel, 3 feet thick. 

 Few foraminifera and these poorly preserved. 



6015. — Oligocene — Emperador limestone. 



From old quarry, one-fourth mile north of west from Empire. 



Cream-colored, coral limestone. 



Few foraminifera. 

 6016. — Oligocene — Emperador limestone. 



From old quarry, one-third mile north of west of Empire. 



Few poorly preserved foraminifera. 

 6019. — Section on west side of Gaillard Gut near Las Cascadas. 



a-f. Oligocene — Culebra formation. 



a. Grayish, rather nodular, impure limestone. 

 Foraminifera few and poor. 



b. Dark, well stratified, very friable, tufaceous material. 

 Foraminifera few and poor except Orbitolites, which are large 



and fine. 



c. Grayish, well stratified, very friable, tufaceous sandstone. 

 Few casts of foraminifera and central portions of orbitoids. 



d. Grayish-green, limy, tufaceous sandstone. 

 Very few foraminifera, poor specimens. 



e. Thin-bedded, light gray to cream-colored, limy sandstone with 

 some partings of light-colored clay. - 



orbitoids and Orbitolitesf only. 



/. Dark, very friable shales and tuffs. 



Foraminifera fairly common, some well preserved, others glau- 

 conitic. 



g. Oligocene — Emperador limestone. 



Light gray to yellowish gray, somewhat sandy limestone. 



Some orbitoids and Orbitolitesf but little else in the way of 

 foraminifera. 

 6020. — Oligocene — Culebra formation. 



Same locality as 6019. 



a-c. Dark-gray carbonaceous clays, friable shales and tuffs. 



a. Foraminifera numerous but of few species, mostly glauconitic, 

 at least in part. 



c. A few Orbitolites in the coralliferous layer. 



