364 



AMERICAN FORESTRY 



WATERVALE BUTTE, A VOLCANIC PLUG OF BASALTIC ROCK IN SOUTHERN COLORADO, 



SURROUNDED BY SOFT SHALE. 



ROBINSON MOUNTAIN, AN EXTINCT VOLCANO NEAR FOLSOM, N. M. MOUNT EMERY, 

 ANOTHER MOUNTAIN OF VOLCANIC ORIGIN, APPEARS IN THE DISTANCE AT THE 

 LEFT. 



color differs but little from that of the 

 lava, and it is no uncommon thing for 

 beast or man to step on a sleeping- rep- 

 tile before he knows of its presence. 

 Fortunately, a rattlesnake will usually 

 give warning of his belligerent intent 

 before beginning hostile operations, and 

 he prefers blissful solitude to the so- 

 ciety of those who never neglect an 

 opportunity to bruise his head. Never- 

 theless, while in the lava fields, the 

 writer learned, after several narrow es- 

 capes, to examine a rock rather care- 

 fully from a biological point of view 

 before examining it geologically or be- 

 fore sitting down on it to rest. The 

 snake is especially peevish about his 

 sun bath, and the man who disturbs 

 slumbers by sitting down too near 

 likely to rise again without 

 his desired r 



RSESHOE MOUNTAIN 



Horseshoe Mountain is the crater 

 cone of an extinct volcano consisting 

 at the surface entirely of scoriaceous 



cinders. It is nearly circular in outline 

 and the rim of the crater is broken 

 down on one side, giving to the crest 

 the general form of a horseshoe. The 

 cone rests on a broad platform of flow 

 lava that is relatively old. Its surface 

 is rolling, and it is covered with soil, 

 but the cinder cone is very young. Al- 

 though it is composed of loose or 

 slightly consolidated material that 

 washes down in considerable quantities 

 with every rain, giving the surface a 

 corrugated appearance, the sides are 

 still nearly as steep as it is possible for 

 them to be with loose material, and the 

 absence of large accumulations of cin- 

 ders at the base that can be attributed 

 to wash from its slopes indicates that 

 the cone still retains essentially the 

 form that the extruded material orig- 

 inally assumed. 



The Horseshoe is typical in many 

 ways of the younger volcanic cones of 

 northeastern New Mexico. During 

 their early eruptions the lavas seem to 

 have flowed out gently, but the last 



