coal. 345 



the strata bend downward, and, beyond a second minor crumple in this 

 portion of the rim and a long shallow curve, gradually rise again in the 

 high bluffs on the northern side of Coal ('reek, 1 \ miles below, here a part 

 of the Eggleston syncline. 



It is possible that immediately east of the anticline just described, 

 instead of part of the structure indicated, a break in the continuity of the 

 strata may occur, the downthrow being on the east of the fault. Some 

 ground for tliis supposition appears in the gulch entering Coal ('reek; but 

 for the possible presence of the fault or a very sharp downward flexure in 

 this portion of the held, the distance between the sandstone knoll and the 

 point at which the measures again begin their long, gentle rise to the cast 

 would he altogether too short to permit the presence of the higher Laramie 

 beds that lie in the concavity of the syncline along the bluffs of the creek. 

 The objection, however, to mapping faults without sufficient evidence has 

 decided for sketching the geology as a succession of unbroken folds. 



Productive areas. — Present productive localities in the Davidson syncline 

 are the Marshall, Allen-Bond, and Davidson, the last of local importance 

 only. Coal was formerly obtained at a number of points along the northern 

 border of the field, but the openings have long been closed on account of 

 limited area or narrowing seam. The heaviest coal seams — from 8 to 13 

 feet thick — occur in the Marshall and Allen-Bond areas, and a .'1-foot scam 

 may be found at several points about the rim of the syncline, as at the 

 Davidson mines and the opening near Coal Creek, and possibly, also, 

 underlying a large part of the deeper portion of the basin. The last 

 occurrence is attested by three or four borings: one in Marshall Gulch at 

 the exit of the Lake basin, which showed a .'1-foot seam of coal at a 

 considerable depth, the total depth drilled being 645 feet; and three a short 

 distance north of the Davidson mesa, which afforded evidence of from 3 

 to 5 feet of coal. The latter coal is the continuation southward of the 

 Allen-Bond and Davidson areas; the former, the continuation eastward of 

 the Marshall. 



TIIK MARSHALL DISTRICT. 



A section of the lower Laramie sandstones and coal measures obtained 

 in the bluff immediately east of the head-house of the Marshall No. 5 mine 



