1897.] NEW YORK ACADEMY OF SCIENCES. 169 



its western side as the break always faced toward the Cerrajon 

 mountain with the uplifted surface dipping away from it the indi- 

 cations were that the intruding force came from that direction. 



My Major Domo refused to act as guide, but reluctantly con- 

 sented to accompany me, and on the following Monday we set out. 

 Our way led through cactus and tangled thorn bushes to the 

 foothills, the Major Domo proving himself a master hand at 

 path finding and we encountered but little difficulty. On reach- 

 ing the foothills he asked me to point out the spot on the moun- 

 tain below the precipices to which I would go. After a careful 

 reconnoitre I picked out a place marked by an overhanging ledge 

 and told him to take me there. Then we went on up and down 

 steep places, making our way over hills and ridges. These were 

 evidently of comparatively recent origin, because the Isays were 

 the same as those in the valley. There were stains and impreg- 

 nations of coal at places and boulders and water worn deposits 

 of limestone were everywhere present. These seemed entirely 

 float material of Cretaceous types similar to that in the lower 

 valley, but more abundantly distributed. After about three 

 hours hard work we reached the lower part of the Cerrajon 

 mountain at the very point I had indicated. Here all trace of 

 the clays and Cretaceous float rock disappeared. Broken angu- 

 lar masses and fragments of a basic eruptive rock were every- 

 where, and iron was abundantly indicated by red brown' stains 

 and disseminations showing that hydrous oxides were present. 

 Our scramble to the top was a rough one and required great cau- 

 tion on our part but, by following the eroded places with great 

 ■care, we finally reached the ledge of rocks capping the mountain, 

 which appeared to be a Cretaceous limestone, barren of fossils 

 and a little coarser than the float rock in the valley and on the 

 foothills. 



It was quite evident that any formations in the valley were of 

 later origin than the mountains and there appeared no reasonable 

 conclusion except that the coal was of Tertiary origin and not 

 very promising. 



Then I turned my attention to the panorama before me. To the 

 west were the Sierra Nevada mountains, their rugged outlines 

 crowned with snow which was aflame with light under a tropical 

 sun. The deep valle}^ separated me from those mountains, and I 

 could see clearly the low divide some twelve miles southwest, 

 where the waters of the Rio Rancheria, starting from the Sierra 

 Nevada mountains on the west turn northeast, and the waters 

 of the Rio Cesar, rising in the Black Andes on the east, turn 

 westward, each running contrary to the other, yet almost on a 

 level, and separated only by low country containing swamps and 



