1896. | NEW YORK ACADEMY OF SCIENCES. ital 
ji oandstone amd: shales 225 Shae das e's se 40’ 
eee OUOl- Wie COM UE Gia sttrs tas Memes 2 Ss a 
9. Sandstone, shale and thin coal beds, about 150’ 
MOT ado coal bed | s2 OSs) nae aoe kee ak 4’ 
11. Sandstone, shale and thin coal beds .......250/ 
Le Miller's: Gulch coal bed’.23 «aoe eee: a 
13. Sandstone, shale and thin coal beds ....... 200/ 
lARLontelierreushales... 4c:sti. nae ae 
The Fox Hills stage of the Rocky Hovis: region is not 
represented in this area. 
The sandstone at the top of the section is shown on a tri- 
angular hill in Coal cafion half a mile below the White Ash mine, 
It is comparatively fine-grained, soft, yellow; evidently the same 
sandstone is shown near Ortiz cafion, where it contains silicified 
trunks of trees. Some of the fragments which have weathered 
out are of large size, one having been seen which is about 2’ 
thick and 3 feet long. This silicified wood is by no means so 
beautiful as that seen in some portions of California and Nevada, 
or even as that from the Chalcedony Park, of Arizona, but the 
replacement is complete and the structure of the wood is dis- 
tinct in many of the specimens. This sandstone passes below 
higher beds at the east, just beyond Ortiz cafion. 
The White Ash coal bed, known as the Boyle, Lucas or White 
Ash vein, is the important bed of the Cerrillos district and the 
only one now worked to any extent. It outcrops on the easterly 
side of Coal cafion, where it was examined from about two miles 
above Madrid to its disappearance below the surface at about a 
mile below that village. It was opened long ago at several 
places and the coal was carted several miles to the nearest rail- 
way station. 
The Boyle mine, about a mile and a half above Madrid, the 
most extensive of the old openings, is, like the other old pits, 
almost shut and the coal cannot be reached, but fragments on 
the dump show that the coal is anthracite. Another opening 
was seen in a small side cafion, less than a quarter of a mile fur- 
ther down, which shows 
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The distance to the bottom of the upper trachyte sheet 
is about 50 feet, but the upper 35 feet of the interval is con- 
cealed; at the Boyle mine it is barely 10 feet and on the op- 
