78 RIO GRANDE GOAL FIELDS OF TEXAS. [bull. 16 
The following is D amble's section published in the Bulletin of th 
Geological Society of America, and previously alluded to: 
General section of Vieja Mountains near San Carlos. 
Feet. 
1. Lava flow, rim rock of mountain 200-30 
2. Sandstones of various colors, interbedded with calcareous clays and vol- 
canic ash 55 
3. Conglomerate, resting unconformably on No. 4 1-1 
4. Lava flow, apparently conformable on No. 5 5 
5. Interbedded brown and red sands, purple shales, and yellow quartzitic 
sandstone 50 
6. Gray and purple shales, with thin strata of sandstone 20 
7. Coal shales, with beds of laminated sands and two seams of coal, highly 
fossiliferous between and below the coal seams 80 
8. Interbedded sands and sandstones, some highly calcareous; fossiliferous.. 25( 
9. Shales with concretions of clayey limestone containing fossils 17! 
This gives a total thickness of over 2,80l 
The general character of the writer's section from San Carlos arroy( 
to the top of the mountain is almost the same as Dumble's. No. 22 o: 
the writer's section equals No. 1 of Dumble's; No. 21 of the writerY 
section equals No. 2 of Dumble's. 
The conglomerate bed and lava flow, 3 and 4 of Dumble's section 
were not seen in going up the mountain at San Carlos. A conglomerate 
occupying the same stratigraphic position as Dumble's No. 3 was founc 
near the base of Gettysburg Peak, a section of which will be describee 
later. Huge bowlders, evidently derived from the disintegration of a 
conglomerate, are very abundant on the low hills in the valley of the 
San Carlos arroyo. 
No. 20 of the writer's section equals for the greater part Nos. 5 and 
6 of Dumble's; Nos. 19 to 15 equals No. 7 of Dumble's; Nos. 1 and 8 
equals No. 8 of Dumble's; Nos. 2 and 1 equals the upper part of No. 
9 of Dumble's. The aggregate thickness of the two sections is prac- 
tically the same. As definite lines of demarcation between the sedi- 
mentary beds could not be found, of course the exact details could not be 
expected to agree. No fossils were found between the coal seams. 
The minimum thickness given for the rim rock was determined, 
instrumentally, by Mr. C. C. Bassett, who made the San Carlos topo- 
graphic map. 
Fossils from section of Vieja Mountains from San Carlos arroyo, 1 mile below San Carlos, 
to top of mountain east of town. 
Fossil from No. U (field No. 301) - 1 
Inoceramus oblongus Meek, possibly identical with I. cumminsi Cragin, but 
these specimens do not have the characteristic posterior plication on 
which that species was founded. 
1 The field numbers are those used by Mr. Stanton. 
