LOWER CRETACEOUS SERIES. 723 



9. Pisolitic limestone conglomerate, with siliceous matrix, containing some 



chert pebbles • 20 feet. 



10. Siliceous grit and conglomerate 40 feet. 



11. Siliceous gray alternating thinly and thickly-bedded h\nestone. about.. . . 450 feet. 



12. Calcareous grit and cherty conglomerate 10 to 15 feet. 



13. Calcareous sandstone and siliceous limestone 30 feet. 



14. Light blue siliceous limestone, with occasional bands of siliceous shell 



breccia, about 300 feet. 



15. Massive limestone conglomerate in siliceous lime matrix. 150 feet. 



16. Alternating siliceous limestone and limestone conglomerate bands, ten to 



twenty feet thick 130 feet. 



17. Light blue limestone 40 feet. 



18. White granular gypsum . 110 feet. 



19. Dark blue, granular, minutely cleaved limestone, metamorphosed and 



filled by calcite veins 120 feet. 



20. White granular gypsum 40 to 50 feet. 



21. Siliceous light grey limestone, partially concealed, exposed 25 feet. 



Total 1156 feet. 



ETHOLEN HORIZONS. 



In Etholen Knobs and vicinity the Malone bed is represented by one hun- 

 dred and ninety-eight feet of gray to dull greenish yellow sands and gritty 

 sand, with thin bands of oysters and oyster shell breccia. Near the base of 

 the sand there is a narrow band of fragile oyster in mass, and in which are 

 occasional rounded limestone pebbles. 



This sandstone is exposed in the bases of the Etholen Knobs, caps the small 

 hills south of the Southern Pacific Railway, southwest of Etholen Knobs, and 

 the small hill at the south base of Sierra Blanca Peak. Elsewhere in the vi- 

 cinity it is eroded and concealed by basin debris. It belongs in the basin 

 northeast of Bluff and Yucca mesas, and it occurs in the east side of Devil's 

 Ridge on the northwest side of Eagle Mountain, where it underlies the same 

 conglomerates, but in greater development than in Etholen Knobs. 



In the sand in Devil's Ridge bivalves, gasteropods, and a small gryphea 

 were collected. 



ETHOLEN BED. 



The Etholen Knobs form a peculiar feature of the topography in the vicin- 

 ity of Sierra Blanca and Quitman Mountains. To a casual observer, and to 

 one who has not worked the stratified rock in the surrounding areas, it is 

 quite difficult to determine their origin. 



The uplift of Sierra Blanca Mountains to the north of Etholen Knobs, and 

 the uplift of the Quitman Mountains to the south of them, has formed a wide 

 and what is now a shallow synclinal fold extending from the one to the other. 



