656 W. T. LEE STRATIGRAPHY OF COAL FIELDS OF NEW MEXICO 



verde and the overlying Galisteo sandstone. A coal bed occurs about 65 

 feet stratigraphicallv above the coal at the old Eogers opening. This 

 coal is 3 feet or more in thickness in some places and in other places is 

 entirely absent. This variation in thickness is due to irregularities of 

 the upper surface obviously caused by erosion. On this unevenly eroded 

 surface lies a light-colored, coarse-grained sandstone that is locally con- 

 glomeratic. No coal nor dark-colored shale, such as is associated with 

 the coal lower in the section, was observed above this sandstone. The 

 rocks above it are pink, blue, green, etcetera, and gradually merge into 

 the undoubted Galisteo sandstone which is typically developed farther to 

 the east. 



A few poorly preserved fossil leaves named in the section were found 

 in this basal member of the Galisteo at Rosrers, but thev are not of a 

 character to render possible the determination of the age of the rocks 

 containing them. 



A diamond drill prospect was made on Waldo Mesa about half a mile 

 south of the old Eogers mine. It has been platted to scale in figure 5, 

 on page 644. The drill passed through a group of coal beds that is obvi- 

 ously the same as the upj^er group of the Eogers section and then pene- 

 trated 187 feet of igneous rock. This rock is a part of a great intrusive 

 sheet that is very prominent farther south, but which does not extend 

 northward to the Eogers mine. Apparently it is not the intrusive sheet 

 of the two drill records previously given, but one intruded at a lower 

 horizon. It underlies the coal beds at Madrid, as is well shown in figure 

 5 of Doctor Johnson's paper (83, page 37). 



A second group of coal beds was penetrated by the drill below the sheet 

 of igneous rock, and these seem to be the same as the lower group of 

 developed coals of the Eogers section and the middle group of the 1,602- 

 foot drill record. This correlation of the groups of coal beds at the sev- 

 eral localities described seems relatively simple, but it is not so easy to 

 correlate the individual beds. The upper group of the "Waldo Mesa drill 

 record corresponds in a general way with the group of coals developed at 

 Madrid, but for some unknown reason there are fewer coal beds than at 

 Madrid. It is possible, on the one hand, that the Waldo Mesa coal beds 

 represent those near the horizon of the Cook and White coal of the Mad- 

 rid section, and that the higher beds were eroded away previous to the 

 deposition of the Galisteo sandstone at the Waldo mesa locality. On the 

 other hand, it seems probable that the Waldo mesa coals may correspond 

 in position with the higher ones of the Madrid section, and that the lower 

 beds of Waldo mesa mav have been destroved bv the intrusion of the 

 iirneous rock. 



