1876.] The Little Missouri “ Bad Lands.” 213 
while in a plastic or half-molten condition. At these points the 
heat was so great that the sands and clays through which the 
fissures extended became thoroughly melted, leaving the walls 
of these fissures with glazed surfaces, vitrifying them to depths 
varying from half an inch to several inches. In some instances 
the melted matter ran down while in a viscous state, solidifying 
in pendant, rounded masses; in other cases it was squeezed out 
through lateral cracks in the walls of the main fissures, congeal- 
ing in similar botryoidal forms. Again, masses are seen in these 
chimney-like mounds that seem to have been twisted and folded 
when in a viscous state, the surface still retaining its waxy lustre. 
In connection with the formation of these fissures and mounds 
there were slight disturbances of the adjoining strata, affecting 
sometimes an area of only a few feet in diameter, and rarely ex- 
tending over many yards. Occasionally, however, the fissures 
extended for considerable distances, accompanied by the usual 
phenomena of intense igneous action already noticed, with a dis- 
turbance of the strata for several yards on either side of the fis- 
sure, where many feet in thickness were lifted and still remain 
highly inclined. We have here, in fact, a series of volcanic 
puffs, or volcanoes in miniature, having their seats of action in the 
burning coal-seam, ten, fifteen, or perhaps fifty feet below. In- 
deed, some of thése disturbed areas present a very broken and 
volcanic aspect, and a geologist suddenly transported to one of 
these localities would feel at first that he must be in the midst of 
a truly voleanic district. He would find that from the tops of 
these apparently volcanic ridges blocks of scoriaceous material, 
ifering in no respect from real volcanic products, have rolled 
down into the adjoining valleys, and lie scattered in masses vary- 
ing from a foot in diameter to those of several tons’ weight. The 
ragged masses of rock crowning the higher points of the ridges, 
like ruined battlements, with the adjoining chasm-like ravines, 
faced. with highly metamorphosed rock, do combine, in fact, to 
Present quite a disturbed and chaotic scene; yet a careful ex- 
amination of even these localities shows that the strata are 
everywhere horizontal, save at such few limited’ areas as those 
already noticed. We find here, as usual, the horizontal beds of 
cinders underlying the metamorphosed strata, differing from 
“hose of other localities only in their greater thickness, and point- 
mg out most conclusively the origin and cause of these local dis- 
Tuptions and former intense igneous action. That the burning 
of the lignite beds is really competent to produce all these effects 
