722 PROCEEDINGS OF THE OTTAWA MEETING 



"In northeastern Arizona there is an arid plain beneath whose scanty soil 

 are level beds of limestone. At one point the plain is interrupted by a bowl- 

 shaped or saucer-shaped hollow, a few thousand- feet broad and a few hundred 

 feet deep ; and about this hollow is an approximately circular rim, rising 100 

 or 200 feet above the surface of the plain. In other words, there is a crater ; 

 but the crater differs from the ordinary volcanic structure of that name in 

 that it contains no volcanic rock. The circling sides of the bowl show lime- 

 stone and sandstone, and the rim is wholly composed of these materials. On 

 the slopes of this crater and on the plain round about many pieces of iron 

 have been found, not iron ore, but the metal itself, and this substance is 

 foreign to the limestone of the plain and to all other formations of the region. 

 The features of the locality thus include three things of unusual character 

 and requiring explanation: First, the crater composed of non-volcanic rock; 

 second, the scattered iron masses ; third, the association of crater and iron. 

 To account for these phenomena a number of theories have been suggested. 



"More precisely, the locality is a few miles south of the station of Canyon 

 Diablo and directly west of Winslow, on the Atlantic and Pacific division of 

 the Santa Fe railroad. The locality is known as Coon butte." 



It is unnecessary at this time to go into further detail of Mr Gilbert's inter- 

 esting discussion. Suffice it to say, while evidences of extensive volcanic action 

 are abundant in the region, there are no lava flows or volcanic materials in 

 the immediate vicinity of Coon butte. The fact of the entire absence of vol- 

 canic materials was the chief reason that the falling star hypothesis appeared 

 so attractive. 



There are in northeastern Arizona and New Mexico myriads of volcanic 

 cones. Many of these are symmetrical cinder cones ; some are low lava cones ; 

 some are cinder cones with breached craters from which basalt flows extend 

 for several miles ; some are the centers from which the country has been 

 flooded with lava for many miles all around. A number of these volcanic 

 vents display evidences of dry explosive action. To one of these special atten- 

 tion is called, for the reason that it is similar to Coon butte in every respect, 

 as described by Mr Gilbert, except that from the bottom of the crater rise two 

 small cinder cones. This locality is known as Crater salt-lake and is in the 

 western part of Socorro county, in New Mexico (plate 80, figure 1). The bot- 

 tom of the crater is a salt-lake, whence the name. In this respect it also differs 

 from the Coon Butte crater. A geological cross-section of the Crater salt-lake 

 is represented in the diagram below (figure 1). 



Figure 1. — Geological Cross-section of Crater Salt-lake. 



Within the crater of the small cinder cone which rises out of the bottom of 

 the lake there was formerly a diminutive lake, which is shown in the accom- 

 panying view (plate 80, figure 2). 



The important feature, however, of Crater salt-lake is that it displays a 

 stage in its formation that is wholly wanting in the case of Coon butte. Con- 

 clusive evidence is here furnished that the craters in plains are the result of 



