SECTIONS 475 



Productus ivesi Newberry c 



Cf. Pustula nehraslcensis (Owen) r 

 Pinna sp. R 



MurcJiisonia terclrra White ? r 



Feet 



2. Thin-bedded, brownish sandstone with a calcareous cement 10 



3. Strongly cross-bedded, light gray sandstone To 



These beds, the Coconino sandstone, disconformablv underlie the Kai- 

 bah limestone (localities 1 and 2). 



c. GRAXD CANYOX OF THE COLORADO RIVER 



As Ave traAcled from Flagstaff around the western base of San Francisco 

 Peak and northwestward to the Grand Canyon, we passed numerous 

 remnants of the Triassic ? Eed Beds left by erosion since the Pliocene 

 uplift. At no place here did we get a section from the underlying 

 Kaibab limestone, which is frequently exposed, into these red Moenkcpi 

 beds. Two miles southeast of Hull Spring, to the southwest of the trail, 

 a ])artial section in the Moenkopi consists of 80 feet of thinly bedded 

 red sandstones, with many ripple-marks and sun-cracks at its base ; above 

 this 10 feet of coarse yellow sandstone containing many selenite veins and 

 bits of wood and charcoal. Throughout the entire region recent cinder 

 cones and lava-flows and ridges of a more or less vesicular malpais (rem- 

 nants of older lava-flows) are numerous. 



A summary of the detailed section made in the Upper Ivailjab lime- 

 stone down the Eed Canyon trail, at the Grand Canyon of the Colorado, 

 is as follows : 



Feet 



1. Gray limestone full of siliceous concretions : 11.5 



2. Alternating light gray and brownish gray limestone 152 



Many ])eds are full of siliceous concretions of various sizes. Several of 

 the beds weather back more rapidly than the others, thus producing cave- 

 zones, though no caves were walled up or gave other evidence of having 

 been inhabited by the ancient Cliff-dwellers. 



Beneath this are 130 feet of alternating red and gray sandstone be- 

 longing to the middle Kaibab. These beds are usually cross-bedded and 

 have a calcareous cement. 



Among the small fossil? collected from the uppermost l)eds were noted : 



Bakeicellia parva M. »fc H. r 



AstarteUa gurlcj/i White R 



Plagiogli/pta canna White c 



Cf. Euphcmus carhonarius (Cox) r 



Cf. Mnrchisouia ? tcrehra White r 



