2007-10-22_PERMIT FILE - C1981014 ‎(3)‎

• Permit No: C1981014
• IBM Index Class Name: Permit File
• Doc Date: 10/22/2007
• Section_Exhibit Name: 2.04.6 GEOLOGY DESCRIPTION
• Media Type: D
• Archive: No

• of the upper Trinidad. These sands are generally fine to medium grained
and light gray to buff in color. Total Trinidad thickness ranges from 40
to 90 feet.
Verme.io Formation. Overlying the delta deposits of the Trinidad are the
complexly interbedded mudstones, siltstones, sandstones, and coals of the
Vermejo Formation. These sediments were part of a vast fluvial delta
plain sequence prograding eastward on the "Trinidad Delta". Differential
compaction of the accumulating sediments and regional subsidence
concurrent with deposition allowed moderate thicknesses of coal to develop
in back river swamps of the delta plain.
The Vermejo Formation is the coal bearing unit of interest in the
Southfield mine area. In ascending order, coal horizons of significance
include the Monarch, Red Arrow, Jack O'Lantern, Vento, Manley, and Rex
Carbon. Several of these coal horizons contain more than one seam and
have been described in the past under more than one name. In addition to
• these six principal horizons, the Vermejo includes several other
recognized coal units within the General Area. Stratigraphic
relationships of the six main horizons and other minor coal occurrences
are illustrated by Figure 3, General Stratigraphic Sequence. Total
thickness of the Vermejo sequence is approximately 925 feet.
The Southfield Mine is currently developing reserves in the Red Arrow and
the overlying Jack O'Lantern coal seams. Both seams are part of the
"Radiant Coal Zone" recognized by the Colorado Geological Survey. The
Red Arrow Seam is a moderate to high sulfur coal ranging in thickness from
4 to 7 feet, consisting of 3 recognizable coal units. Atypical face
description is as follows:
Upper Unit 1.0' coal
Upper Parting 0.2' bone / carbonaceous shale
Middle Unit 2.2' coal
Lower Parting 0.5' bone
. Lower Unit 2.0' coal
2.04.6-5