1891.] A Recent Lava Flow in New Mexico. 527. 
miles north of the volcanic cone, which indicate the former exist- 
ence there of not only a pueblo, but extensive irrigation works. 
These ruins are quite famous in New Mexico under name of the 
Gran Quivira. At present there is not even drinking water 
within many miles of the ruins, much less water for an irrigation 
- supply. Furthermore, the canals are said to be at present tilted at 
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various angles, as if disturbed by some subterranean disturbance. 
If this be true, we have not only a recent eruption, but also one 
which by either surface or subterranean disturbances has destroyed 
canals, and even caused a spring or stream to disappear. As I 
have said, whether this eruption has taken place since the time of 
the Pueblo Indian occupation of New Mexico or not I am not 
prepared to state ; but certainly this isolated flow is in no way con- » 
nected in point of time with the great basalt flows of the Tertiary 
in New Mexico, but is vastly more recent. The time of eruption 
must be reckoned, if not in hundreds, in thousands rather than 
tens of thousands of years. The matter deserves, I think, a much 
more careful study than I was able to give it, and I hope that 
some one may find it convenient to give it sucha study. 
Am. Nat.—June.—2. 
