TERTIARY COAL MEASURES OF GUNNISON COUNTY, COL. 693 



able coal, some of it having fixed carbon enough to be rated as an anthracite, 

 and showing remarkably well in the face for this No. 2 vein. Numerous cracks 

 or faults occur in the roof or sandstone, now making mud seams ; near these, the 

 coal was broken and worthless. 



A new opening has been made into the hill from the head of the gulch, now 

 nearly 300 feet in. On one side of this opening the coal is constant; on the 

 other, a fissure-vein filled with eighteen inches of calc spar, coming from the di- 

 rection of 0-Be-Joyful Gulch. This will certainly carry mineral with depth, and 

 makes a connecting link through to the veins of Washington Gulch, and abso- 

 lutely proves in fact what I had first advanced as a theory, that in localities the 

 mineral veins would be found passing through coal seams. 



I followed these Tertiary rocks across the head of Washington Gulch, be- 

 tween Gothic and Baldy Mountains, back of Belleview Mountain, down the val- 

 ley of Rock Creek, over Mineral Point, Meadow and Arkansas Mountains; and 

 could see where they again came in below the lake near Rock Creek. Here 

 erosion shows these old Tertiary sea-bottoms to have been deep enough for the 

 coal-seams to again appear, and report says there are much stronger veins than 

 those in the particularly described basins. 



The coal series of the Front Range of Colorado, as well as in Middle and 

 South Parks, belong to the Cretaceous age. While I found Cretaceous rocks in 

 abundance on the west slope in the section examined this season, I did not find 

 the coal of the same age, except in one locality, namely, Chicago Park, two miles 

 from Pitkin. Here some holes have been sunk, disclosing the coal, but also 

 showing, from evident and easily perceived causes, that it is worthless, being 

 highly charged with iron and sulphur. The quantity here also must be very 

 limited. 



As to the character of plants that grew in these waters to make these coal- 

 seams, there appears to be such a diversity of opinion among the highest authori- 

 ties, that I do not think this character of metamorphism has been sufficiently 

 proved as yet. This I would like to record, that from my personal work this 

 season, the great difference between ordinary bituminous coal and that which is 

 called the coking coal, would certainly seem to arise from a material difference 

 in the original vegetation. 



I spent five days at Jack's Cabin, examining the rocks in connection with the 

 lava outcrop, principally, because I had been informed that large bodies of hemat- 

 ite iron existed here ; in fact, one of the United States geological reports gives 

 this locahty as the place where the largest body in iron ever seen occurs. After 

 five days' work, I could not find it, and came to the conclusion that the first ex- 

 amination was a hasty one and the conclusion jumped to that this black lava 

 was hematite iron, when, as a matter of fact, it does not contain ten per cent of 

 iron. 



I thoroughly examined the eroded basin between the two lava mesas, hoping 

 to find evidence of the coal-seams here, and that the heat and pressure from the 

 over-lying eruptive rock would have changed such coal to an anthracite, but I 



