568 



SCIENCE. 



[N. S. Vol. XXIV. No. 618. 



ORIGIN OF THE DEPRESSION KNOWN AS MONTE- 

 ZUMA's well, ARIZONA. 



The singular bowl-shaped depression known 

 as Montezuma's Well on Beaver Creek, Ya- 

 vapai County, Arizona, is one of the noted 

 natural wonders of that territory. It is fre- 

 quently visited by tourists and others who get 

 so far into the interior of Arizona as Camp 

 Verde, from which the well is twelve miles 

 distant. Hinton in his 'Handbook of Ari- 

 zona' (1878) gives a fair representation, by 

 a wood-cut, of one side of the well. 



The depression is in the midst of a nearly 

 level area; it is nearly circular, 500 to 600 

 feet in diameter, with vertical walls, or sides, 

 from 30 to 40 feet downwards to the head 

 of a talus slope extending to a circular pool 

 of water, said to be of unfathomable depth. 



The popular theory of the origin of this 

 cavity and well in the plain is that it is vol- 

 canic; a crater, like a pit-crater. While 

 there is a resemblance in form to a pit-crater 

 there is no other point of resemblance. There 

 are no volcanic rocks or traces of lava, except 

 numerous broken metaltes left by the ancient 

 cliff-dwellers who once dwelt in the cavernous 

 spaces in the limestone walls around the pool. 

 The water is not stagnant, it flows out by a 

 subterranean channel to the adjoining valley 

 of Beaver Creek, from which, probably, the 

 supply is received at some more remote point 

 above. 



This depression is evidently the result of 

 caving-in, a falling down, of the roof of a 

 cavern formed by running water in the nearly 

 horizontal limestone strata. Most of the 

 debris of the former roof which was engulfed 

 in the cavern has no doubt been largely dis- 

 solved and washed away by the flowing water. 



The existence of once inhabited rooms, or 

 chambers, around the well in the overhanging 

 limestone cliffs, and also of extensive ruins 

 of stone buildings above, around the borders 

 of the depression, confirms the other evidences 

 of the great antiquity of the well. 



There are other peculiar basin-shaped de- 

 pressions in the general surface in the vicinity 

 of Flagstaff and Walnut Creek in Coconino 

 County whose origin may be similarly ex- 

 plained or, perhaps, referred to the solvent 



action of surface waters sinking or percolating 

 downwards through calcareous strata to some 

 subterranean channel, or by subterranean 

 streams. 



The peculiar depressions in the soil of the 

 lead and zinc region of Wisconsin, often seen 

 at intervals along certain lines upon the sur- 

 face, may be similarly accounted for. They 

 indicate the downward flow of solvent waters 

 to and along the ' crevices ' in the horizontal 

 limestones and thus are indicative of lodes 

 or of ore to the miners. 



The foregoing described phenomena suggest 

 that the remarkable crater-like cavity known 

 as ' Coon Butte Crater ' may have similarly 

 originated. This suggestion is made with 

 some reluctance, inasmuch as I have not 

 studied the locality. But it seems as if all 

 the conditions so well and fully described by 

 Mr. D, M. Barringer, and Mr, Tilghman, in 

 their memoirs (Proceedings of the Academy 

 of Natural Sciences of Philadelphia, Decem- 

 ber, 1905) may be explained upon the hy- 

 pothesis of a sink or downward flow of surface 

 (meteoric) water carrying away by solution 

 the lime of the calcareous sandstone, reducing 

 its volume, or forming cavernous spaces, which 

 permitted the upper unsupported beds to fall 

 in. Such solvent action would leave the 

 silica of the calcareous sandstone in a divided 

 pulverulent condition, much as it is found, 

 with here and there portions with less lime or 

 less decomposition. The subsidence of the 

 area would carry down with it any meteoric 

 fragments which were on the surface or in the 

 soil, and to considerable depths. 



The numerous masses of iron oxide or 

 ' magnetite,' as described, are doubtless the 

 residual fragments of siderolites originally 

 highly charged with nodules of sulphides and 

 phosphides, and probably with chlorine. The 

 continuous oxidation and exfoliation of some 

 meteorites, even when protected from the ele- 

 ments in museums, are familiar examples. 



Wm. p. Blake. 



QUOTATIONS. 



the HUXLEY LECTURE. 



Professor Ivan Petrovitch Pawlow, the 

 celebrated professor of physiology at the Uni- 



