PERMFILE130306

• Permit No: C1981014
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: EXHIBIT 23 SUBSIDENCE INFORMATION
• Media Type: D
• Archive: No

Syncline. The Chandler Syncline is apparently related to uplift
and thrust faulting activity to the southwest in the vicinity of
the Wet Mountains. Immediately to the southwest of the proposed
mine is the Wet Mountain fault which separates Tertiary to
Cretaceous Age sedimentary rocks from the Precambrian metamorphic
rocks of the Wet Mountains. The bedrock observed in the vicinity
of the mine site includes in order of youngest to oldest the
Poison Canyon Formation of Tertiary Age, the Raton Formation of
Tertiary to Cretaceous Age, the Vermejo Formation of Cretaceous
Age, the Trinidad Sandstone of Cretaceous Age, and the Pierre
Shale of Cretaceous Age. The bedrock overburden .above the
proposed mine consists of the Upper Vermejo Formation and the
overlying Raton and Poison Canyon Formations. All of these
• formations are very similar in nature consisting primarily of
interbedded sandstone, siltstone, shales and coals. The majority
of the coal in this region is contained within the Vermejo
Formation. The current mine plan involves extraction of coal
from the Red Arrow Seam and the Dirty Jack-O-Lantern Seam. In
many cases, the bedrock is obscured at the surface by a deposit
of Quaternary Alluvium. in particular, the Verdos Alluvium and
Rocky Flats Alluvium, both of Quaternary Age, are present above
the mine site. It appears that these alluvial materials can
reach thicknesses of up to 40 feet in some areas.
The photogeologic map, shown on Exhibit 1 of the permit
application (3/83T prepared by Dorchester Coal Company,
. indicates the position of the major mapped faults in the area.
11