SUEVEY OF COLOEADO AND NEW MEXICO. 55 



line of separation between the tertiary and cretaceous formations in this 

 region. If this is true — and I am confident that it is — there is an entire 

 want of continuity iu the sequence of the beds. 



In a dry gulch, about two miles west of Trinidad, there is a bluff with 

 about thirty feet of black cretaceous shales, No. 2, with an irregular 

 surface, on which is deposited ten to fifteen feet of partially worn pebbles, 

 held together by a carbonate or silicate of lime. Much of it looks like 

 tufa. In this place there is quite a deposit of what appears to be the 

 excrement of birds or bats, but whicb has been oftentimes mistaken for 

 the indications of petroleum. This deposit of ijudding-stoue seems to 

 be quite common, and is well shown in the banks of all the dry creeks. 



Eaton Peak is the highest point in this region, and I have estimated 

 it to be about eight hundred to a thousand feet above Purgatory Creek. 

 It is capped with a huge mass of basalt, and underneath it is a great 

 thickness of the tertiary strata, some layers of which are full of impres- 

 sions of leaves. I distinctlj?^ recognized Sabal, Platanus, Carya, Cornus, 

 and Populus. In the muddy sandstones, just underneath the coal bed, are 

 an abundance of a species of pine cone in the form of casts. 



Crossing the road, about four miles west of Trinidad, is a beautiful 

 illustration. of a dike, about twelve to fourteen inches wide, with a strike 

 twenty degrees south of east, and a slight inclination southward. It is 

 thrust up through a considerable thickness of the lower tertiary beds. The 

 rock seems to be very heavy, though full of cavities, filled with a whitish 

 substance which cuts easily with a knife — calcite or carbonate of lime. The 

 hills north of Fischer's Peak, through a bed of coal. A little further the 

 mass of the rocks has a rather bright, black color. This dike runs along the 

 road and passes over another dike, which is more obscure and not as well 

 defined. On the east side of the road are several outcroppings of coal 

 in the sides of the hills. The coal is about four feet thick, with arena- 

 ceous clay above, passing up into sandstone. 



About five miles south of Trinidad, on the east side of the road, is 

 another exposure of the coal in the banks of a little creek, which is 

 worthy of notice. From the water's edge up there are layers of fine- 

 grained sandstone filled with bits of vegetable matter. Above this comes 

 a bed of black shale, four feet, passing up into a gray sandstone, rather 

 concretionary and irregular in its line of deposition. This bed is fifteen 

 or twenty feet, sometimes solid sandstone. Then in a little distance it 

 will be separated by a bed of shale or black slate. Above the sandstone 

 is shale with iron ore ; then about two feet of mud sandstone ; then very 

 black claj'^, nodular in some places — the middle portion impure, earthy 

 coal — five feet; then two feet laminated bluish gray sandstone, with stems 

 aud bits of vegetable matter scattered through it ; then black coaly shale, 

 — eighteen inches ; passing up into a layer of good coal — twelve inches; 

 black shale — fourfeet; then a layer of sandstone — three inches; then black 

 shale passing up into arenaceous clays; then black shale — six feet; then 

 a bed of coal — six or seven feet. Immediately above the coal bed, without 

 any clay, is an irregular gray, rusty sandstone, full of concretionary 

 layers, and readily yielding to atmospheric influences. Then comes drab 

 arenaceous clay — three feet; good coal — four feet; drab arenaceous clay, 

 with very large concretionary masses of brown iron ore. This clay bed 

 must be fifteen or twenty feet thick, passing up into a soft yellow sand- 

 stone, fifteen or twenty feet tliick, and capjjing the first hill. Then 

 alternations of sandstone and clays continue far up the distant hills for 

 hundreds of feet, until we reach the mesa or basaltic cap. Here some 

 coal beds show plainly along the road for six or eight miles above Trin- 

 idad, and still higher up on the hills, now concealed by vegetation, I 



