GEOLOGIC RECONNAISSANCE OF TAOS RANGE 739 



At the head of Pueblo Creek the Pennsylvanian rests on 

 pre-Cambrian quartzite. A north-south fault crosses the divide 

 between Red River and Pueblo Creek, bringing the sandstones 

 and grits into juxtaposition to the granite on the west. A little 

 farther north two minor step faults cross the ridge from northwest 

 to southeast. North of this exposure the sedimentary rocks are 

 confined almost entirely to the area east of Red River. The 

 river has cut a deep canyon into the sedimentaries, exposing on 

 the east slope a thickness of nearly 1,000 feet 01 the Pennsylvanian. 

 About 200 feet above the creek bottom the following approximate 

 section is exposed: 



Feet 



Red sandstone, very fine grained 100-150 



Arkosic, light-colored sandstone, at least 200 



Gray, fossiliferous limestone 50 ± 



Dark-gray shale, carbonaceous in places 50 =t 



Light-gray quartz conglomerate 40 ± 



Concealed base 



A number of outliers of the Pennsylvanian are situated on the 

 east slope of the main range and extend from Bull of the Woods 

 to the head of Indian Creek. The most interesting outlier, a 

 block faulted down on at least three of its four sides, lies east of 

 Larkspur Point. (See Fig. 2.) A partial section of it measured 

 just south of Sacred Lake is given below : 



Feet 



15. Light-gray, very hard and massive arkosic sandstone . . 15 



14. Brownish-gray, shaly limestone 30 



13. Lime cemented conglomerate (description below) .... 20 



12. Puddingstone conglomerate 10 



II. Dark-red, very dense shale 20 



10. Light-gray arkosic sandstone 12 



9. Puddingstone conglomerate 25 



8. Gray, massive, argillaceous limestone 45 



7. Light-brown, medium-grained calcareous grit 20 



6. Grayish-green shale, non-laminated 6 



5. Puddingstone conglomerate (very coarse) 25 



4. Brownish-gray, gritty limestone, fossiliferous 21 



3. Red shale, somewhat arenaceous 9 



2. Puddingstone conglomerate (extremely coarse) 32 



I. Dark- red, very dense, massive shale 15 + 



305 

 Concealed base about 50+ feet above schist 



