Show THE TOP guju TTE 1 f v COAL oai analysis by the united states Ue geological survey which will be read with interest the following i g thy tho coal of this section was prepared for the express by beatrice D wood of the united states geological survey an examination by the united states geological survey of coal fields in nor northwestern northwest thweatt rn colorado and northeastern utah during the past summer in included a study of the small field near vernal utah these coal beds aro alag of interest although of rather small extent L ing the present source of supply for domestic use in the prosperous agricultural community about vernal in the ashley valley and near green river the coal vi 11 somewhat unique in comparison with the great bulk of col colorado orado coals as it is found in rocks of greater age geologically than those of the more extensive fields to the east cast it occurs in rocks described as of benton age cretaceous s in many localities and corresponding to the lower part of the mancos shale as defined inthe in the reports on the southwestern and northwestern colorado coal fields other benton coals that are commercially valuable are reported west of the vernal field in utah notably near Co alville and at other localities near the wasatch mountains only one bed of coal in this formation appears to be of workable thickness near vernal this bed is from 6 5 to 7 feet in thickness and is broken into a number of benches by layers of bony I 1 coal that must be taken out in mining so that the total amount of good coal in the bed averages from 3 12 to about 4 12 1 2 feet chii bed is opened by several working mines and has been very thoroughly pros prospected petted along its outcrop so that tha t representative samples of the coal were obtained at various points samples were taken for analysis in all of the working mines and also from one mine that had not been worked for some time these results are of special interest for comparison with the previously published analyses of coals from colorado fields and also for a comparison i of the product of various mines now being worked in the vernal field in relative efficiencies as shown by the calorific values determined the fuels compare favorably with much of the coal from the white river and yampa river fields of colorado although they are perhaps slightly below the average coal found in those fields among themselves the variation as seen along the outcrop of the bed is very slight probably not greater than that which may occur in almost any coal bed the only apparent exception to the similarity of the coals is in the mine duo due north of vernal which had not been worked for sometime some time when the sample was taken and the coal of which had evidently deteriorated somewhat by exposure to the air the lower limit of efficiency of high grade bituminous coals as shown by such calorific determinations is approximately british thermal units so that the best of the coals in this region fall just within that class an obvious disadvantage of the coal is the great amount of bone that the bed contains which makes the mining of the marketable product much more expensive than it NA would otherwise be and also probably pio bably makes the product relatively high in ash |