148 KANSAS ACADEMY OF SCIENCE. 



of thick or thin coal-beds were laid, with intervening layers of sand- 

 stone and shale. As sea saurians and marine mollusks have been 

 found in supposed Laramie, it is probable that at times the outlets 

 may have been so lowered as to admit the influx of tides or currents, 

 producing brackish conditions, but the exclusive fresh-water view is 

 intended to apply only to New Mexico. In the disintegration of 

 granitic rock, the feldspar and mica and other basic constituents yield 

 and are washed away before the quartz is reduced to sand; hence the 

 shale in the Laramie is generally overlaid by sandstone, and the coal- 

 beds have mostly a sandstone roof. This enables them to be operated 

 with greater security and less labor and expense than in many other 

 coal-fields. 



The workable coal-seams vary in thickness from three and one-half 

 to forty feet ; where the latter extreme is found want of transportation 

 facilities renders the seam unavailable. It lies in the northwest part 

 of the territory, between the western division of the Atchison, To- 

 peka & Santa Fe railroad on the south and the Denver & Rio Grande 

 railroad on the north. The field embraces more than a million acres, 

 and is 125 miles in length. The southern exposure of this [coal-field 

 is exploited about Gallup, near Arizona territory. The coal is a lig- 

 nite, in two series of seams, with 400 feet of rock between them ; but 

 it borders on the bituminous, and is sometimes strictly of that grade. 

 In these coals resinous gum is found distributed in small masses 

 about the size of a pea. It crumbles easily and is difficult to collect. 

 It was first discovered in 1873, and was then new to science, and was 

 given the name "wheelerite," in honor of Lieut. George M.Wheeler, 

 engineer in charge of the exploring expedition. From these mines 

 are also obtained sections of trunks or limbs of exogenous trees, with 

 the concentric rings plainly visible. One of these sections is in the 

 rooms of the chamber of commerce at Los Angeles, Cal. 



The Coal Measures in the region of Santa Fe are much broken by 

 intrusive dikes and sills of porphyritic lava; so, also, in the north- 

 east and in the southeast parts of the territory. The interesting con- 

 sequence is the change of whole seams, or only portions, from 

 bituminous to anthracite, or to semi-anthracite ; the best anthracite 

 being equal in quality to the Pennsylvania product. In one in- 

 stance, near Cerrillos, a plutonic sheet, 350 feet deep, lifted the 

 upper end of an inclined coal-bed and its floor of sandstone and 

 floated them over another part of the same, metamorphosing both 

 the transported and the in situ portions. Coal is found on the tops 

 of some mountains in small patches, whether of Laramie age is 

 doubtful, but Laramie coal is found in each of the four quarters of 

 the territory, which seem to have been wooded, then as now, with 



