284 BULLETIN OF THE 



from the alluvial plain, the former bed of Lake Titicaca. To the 

 westward of Puno we find at Vilque, a distance of about fifteen miles, 

 another basin. Again at Santa Lucia, near Maravilles, a third basin 

 still farther to the westward, resting upon underlying conglomerates 

 and metamorphic rocks, in which the strata dip to the eastward, and 

 finally still a fourth basin at Sumbay Station, on the Puno and Are- 

 quipa Railroad, at a distance of about fifty miles east of Arequipa. 

 Between the Santa Lucia and the Sumbay basins there is an extended 

 volcanic deposit forming the elevated plain of Vincocaya, at a height 

 of nearly 15,000 feet. Professor Orton also mentions Compuerta as 

 a Jurassic locality, but as he did not collect the fossils himself, the 

 presence of a Jurassic outlier between the basins may be questioned 

 for the present. Of course I do not wish to be understood as stating 

 that there are only four such parallel basins, — a far greater number 

 will undoubtedly be observed hereafter. At all these points there 

 has been bituminous coal found and a number of beds opened, on 

 which more or less exploring has been done. On the northeast end 

 of the peninsula of Copacabana, at Yampopata, a small coal-mine has 

 been opened, capable, with the limited number of men employed, of 

 producing about thirty tons a day of a fair quality of coal, which 

 has repeatedly been used by the two small steamers plying at inter- 

 vals on the lake. The coal is a grateful substitute for the use of dry 

 llama-dung, for which you are frequently compelled to wait until a 

 sufficient supply can be collected. The works of the coal-mine at 

 Yampopata consist of a tunnel driven in at right angles to the bed 

 at the water level of the lake, giving a back of some six hundred feet. 

 From the tunnel a gangway has been driven a tolerable distance both 

 ways. But all the appliances for mining are so crude, and the knowl- 

 edge of coal-mining so defective, that with the present system no 

 great results can be accomplished. Yet this mine is situated on the 

 shore of a lake some one hundred and twenty miles long and forty 

 miles wide, round which is gathered a population of no less than 

 200,000 Indians living in a region entirely destitute of fuel, unless 

 the few bushes sold at a fabulous price for cooking purposes can be 

 dignified by that name. Even this source of fuel is becoming annu- 

 ally more difficult of access, so that whole villages are compelled to 

 use dry llama-dung and other manure as their only combustible. The 



