continuously from the time that they first cut through the sod till they empty into the Little Missouri, their courses varying in length. from ten to twenty miles. None of these creeks, except Cannon Ball, is shown on the map. Lignite on Williams Creek.-The lower portion of Williams creek was not visited, though lignite is reported as showing abundantly along this portion of course. Beginning six miles from its mouth, the stream was followed west for two miles and a number of good exposures were examined. At this point its bed is approximately 200 feet above the water of the Little Missouri. The section shown in the cut banks was as The lignite seams dip toward the east, rising toward the west somewhat faster than the creek, or some thirty or forty feet per mile. These seams were traced by a series of nearly continuous outcrops for almost a mile along Williams creek, and for a considerable distance along one of its tributaries, their thickness and quality remaining constant. Lignite on Garner Creek.-Some lignite is exposed on this creek, though not as much as along those adjacent. Good springs are common in its upper course, and a little digging will probably reveal the lignite seams from which they come. On a branch of Garner creek, which unites with the main stream eight miles west of the Little Missouri, a four-foot seam is said to outcrop. Lignite on Horse Creek.-Along Horse creek for more than six miles lignite seams varying in thickness from three to six feet are exposed at various elevations. Near the Stewart ranch six feet of coal, four of it excellent in quality, are mined in a draw thirty feet below the top of the divide which here separates the waters of the Little Missouri from those of Beaver creek. were Lignite on Coal Canyon.—An abundance of lignite is exposed along the deep ravine that bears this name. The seams examined and measured at a number of points from one to three miles west of the river. The section there given was: The lignite at this point is shown in plate XIII. An analysis of dried material taken from a number of points in the seven-foot seam shows: Volatile matter Fixed carbon 38.57 52.47 8.96 100.00 The lignite in Coal Canyon at this point is approximately on a level with the upper thick seam which will be described as outcropping in the bluffs of the Little Missouri, a mile and a half to the east. Lignite on Cannon Ball Creek.-This creek empties into the Little Missouri about twenty-five miles south of Medora, and is a stream of some importance, its valley a mile from the mouth being nearly a mile wide. Six feet of good lignite outcrop at this point in its course, two feet above low water level, and the stratum was traced continuously for 100 feet, till it was concealed by alluvium. Along the Little Missouri and in all the ravines in this vicinity, four and five seams of lignite are exposed, usually at an elevation much higher than that of the seam just noted. Well up in the buttes is a five-foot seam, plainly burned out over a large area, remnants only remaining here and there. While all about are masses of burned clay, there is none over the areas where the lignite is intact. Lignite on Boise Creek.-The outcrops seen here were of thin seams only, though the lower part of the valley where they are usually more abundant was not visited. Some miles above the mouth two and three seams, each two or three feet thick, were occasionally exposed. Lignite on Bacon Creek.-At the J. C. Gamel ranch in Township 133, Range 104, Section 20, a very thick seam outcrops and is mined by stripping for use in the neighborhood. The elevation of this lignite is considerable, only seventy-five feet less than the average level of the surrounding country. The thickness of the seam, as determined by measurements made at this point, is twenty-four feet. As now exposed it does appear to be of the best quality, though surface weathering may be offered in part or wholly in explanation of its apparent inferiority. An analysis of dried samples taken from the surface shows: Volatile matter Ash ..... 37.59 55.90 6.51 This seam is illustrated in plate XIV. Other seams are said to be exposed in the banks between this point and the Little Missouri river. Lignite on Sand Creek.-Reports of a lignite seam forty or more feet thick, which was said to occur thirty miles southwest of Dickinson and about an equal distance from Medora, directed attention to the country east of the Little Missouri. Directions for finding the "big seam" were somewhat vague, but that it was located on Sand creek at length became certain. When found, it proved to be near A. E. Russel's ranch, and in Township 135, Range 101, Section 31, on land that the surveying party, which had just passed through, had determined to belong to the Northern Pacific railroad. Lignite outcrops continuously for a quarter of a mile along the creek. At the north end of the exposure the section given was: 6. Sandstone 5. Clay 4. Lignite 3. Clay FEET 2 10 2 2 15 3 INCHES 2. Lignite 1. Clay Water level At the south end the lignite reached the remarkable thickness shown below: INCHES How far this thickness is maintained could not be determined, for, while the outcrop was traced south of the point at which the last section was taken, conditions for measuring the total thickness were not favorable. The rapid thinning of the seam to A Gulch in the Bad Lands Which Is Being Cut Rapidly in the Wash That Has Filled an Older Gulch. |