898 



SCIENCE. 



[X. S. Vol. XXI. Xo. 545. 



Fayant and E. O. Hovey has finished its first 

 exploration of the northern part of the Western 

 Sierra Madre ^Mountains of Mexico. A sum- 

 mary account of the first half of the trip, from 

 El Paso to Guaynopita, has been given to the 

 readers of Science. The second half of the 

 journey was no less interesting than the first 

 and was fully as productive of scientific ob- 

 servations. 



Leaving Guaynopita by pack train on March 

 11, the first stage of the journey was the climb 

 of 3,500 feet out of the Yaqui (Aros) canon 

 in which Guaynoj^ita is located on to the great 

 mesa out of which the mountains of the region 

 have for the greater part been carved. The 

 contrast in vegetation between different parts 

 of this section may be illustrated by the state- 

 ment that fan-leaf palms flourish in the gorges 

 near the river, while on the high mesa one 

 finds the great long-leaf sugar pine predom- 

 inant. 



Our course lay southward for sixty or 

 seventy miles along the broad plains and nar- 

 row divides forming the mesa, or connecting 

 different parts of it, and we had abundant 

 opportunity of studying the topography of the 

 great Tutuaca Canon, which is tributary to 

 the Yaqui (Aros), and of observing the contest 

 for the drainage of the plateau between the 

 streams flowing to the west and those flowing 

 to the east. The dissection of the plateau 

 is more pronounced toward the west, and our 

 cross-section of the canon of the Tutuaca 

 River from its eastern boundary at the edge 

 of the Mesa Venado disclosed acid and basic 

 lavas, tuffs, agglomerates and conglomerates 

 through six thousand feet of beds. The west- 

 ern rim of the Tutuaca Canon is near the 

 important Dolores mineral district. Some of 

 the extensive igneous action has been accom- 

 panied and followed by strong mineralization 

 of veins. At Dolores a fifteen-stamp mill of 

 the most up-to-date construction is just being 

 completed under the supervision of Manager 

 J. Gordon Hardy for the treatment of the 

 rich gold and silver ores of the Alma Maria 

 vein hy the direct cyanide process. 



Near Dolores we turned southward again 

 and pursued our course along a series of high 



mesas, divides, arroyos and river channels un- 

 til we reached the little Indian town of 

 Yepachic. In this part of our route we passed 

 through three or four fertile ranches and at 

 Yepachic found the people (Tarahumares and 

 Pimas) living for the most part from the 

 tillage of a small alluvial plain surrounded by 

 low mountains. Here we turned westward 

 again and within a few miles reached the 

 Cerro Boludo (Bald Mountain) district, which, 

 like several others on our route, is character- 

 ized by a mineralized quartz vein twenty to 

 eighty feet wide which can be seen traversing 

 hill and vale for miles. 



Six or eight miles south of Cerro Boludo 

 lies the little Mexican camp of San Francisco, 

 where a diminutive two-stamp mill feeds a 

 primitive arrastra as a preliminary to pan 

 amalgamation of the gold. Thence the 

 Ocampo trail leads over a divide and across 

 the deep caiion of the Rio de Mayo, down into 

 and out of the Rosario arroyo before the great 

 arroyo is reached in the bottom of which, at 

 the junction of two branch arroyos, is crowded 

 the mining camp of Ocampo — a place better 

 known by its old name of Jesus Maria. This 

 is the site of many rich gold and silver mines, 

 the most famous of which is the Santa 

 Juliana. 



From Ocampo to Miiiaca, 100 miles, the trail 

 crosses the high mesa, which has a gentle slope 

 eastward and is partly dissected by compara- 

 tively shallow canons of varying depths. 

 Miiiaca, the present terminus of the Chihua- 

 hua and Pacific Railway, is in a beautiful 

 broad basin about 7,000 feet above tide, which 

 is traversed by the headwaters of the Rio 

 Verde, a tributary of the Yaqui (Aros) River. 



At ilifiaca our party took train for Chihua- 

 hua and thence went by rail to El Paso, com- 

 pleting our noteworthy circuit in the western 

 Sierra Madre Mountains of northwestern 

 Mexico. The circuit was not very long, com- 

 pared with the mileage of some exjieditions, 

 but the results along lines of physiographic, 

 dynamic and economic geology are of impor- 

 tance and will be published as soon as they 

 can be put into proper shape, while the photo- 

 graphs taken illustrate as completely as prac- 



