DESCBimvi: ;i-:o(;uAi'UY. 9 



breccias ami lirecciateil porphyries predominate. Their sui faces are at times black as coal, at 

 others of a deep crimson, again of an ashy -^ra\ . and in.t nnfrei|iient 1 y arc striped in \\< 



i.thle shade. Though there are places where the. inclination in iu u contrary direo 

 ti.ni, the general dip is to tlie west. However, such are the characters of the rock*, tip- 



a variety ami so many modifications of species, that one must acknowledge nature 

 lrought together, at this last pinnacle of the system, a specimen from almost every class 

 composing the secondary formation of the western slope of the Andes. At this immediate 

 point, the summit is composed of a rounded mass, entirely without vegetation, covered with 

 telil.spatliic ami ijnartzose detritus, forming gentle slopes marked hy moderate ravines. 

 Though snow was seen on the south sides of cones somewhat higher than the portezuelo, and 

 even in the deep ravines much lower down, none was found in the pass 14,522 feet above the 

 sea in the latter days of March. 



There is a striking contrast in the configuration and colors of the two sides of the Andes, as 

 set 11 from the summit here. To the west there is a complete reversal of the primary formation ; 

 escarpments overturned, stratifications distorted and interrupted, and, indeed, no two mount- 

 ains of the same constituents, form, or shade. On the other hand, eastward we see gentle 

 declivities, with beds of nearly horizontal and rarely interrupted rocks, whose extremities form 

 lines almost parallel with the horizon; few tints, vegetable or mineral, to shade the picture, 

 and only a small number of conical and isolated summits, distant from the line of the crest, 

 by which the monotony is partially relieved. There is a conical peak to the northward, some 

 eight or ten leagues, which is apparently much higher, and the guides say that it is perpetually 

 covered with snow ; but those in the immediate vicinity of the pass do not rise more than 300 

 or 400 feet above it. All beyond is terra incognita, except to the professional mine hunter or 

 smuggler. 



LAGUNA and DONA ANA Passes, in the province of Coquimbo. The first portion of the road 

 to these passes is through the valley of the river Coquimbo, where, from the number of its 

 affluents, there is a much greater supply of water, and a broader space of alluvial soil, to 

 render it more cheerful than the barren rocks of Atacama. Within the first nine leagues, the 

 river is increased by a stream from the northeast through quebrada Santa Gracia, near whose 

 source are the rich silver mines of Arqueros, more rare for their combination with quick- 

 silver in a pure state. At a short distance from the left bank are some of the most productive 

 copper mines. The valley now makes a short turn to the northeast, and then, resuming its 

 original direction to the E.S.E., it continues in the same general line by the windings of the 

 river more than thirty leagues farther. Midway this distance it becomes quite a plain, on 

 which the villages of Elqui, Tambo, San Isidro, and Diaguita, principally occupied by persons 

 engaged in mining operations, are, amid vegetation and fruit-trees of great luxuriance, 

 reminding one of the most fertile portions of the republic. Fifty miles in a straight line 

 from the ocean, though more than twice that distance in its serpentine course, the Coquimbo loses 

 its name ; its main and northern branch, whose origin is more than a degree of longitude 

 farther to the east, being first called the Laguna, and afterward the Turbio, until the union 

 with tlie Claro, a small limpid stream from the southeast. The contrast of the colors in the 

 two streams is very striking, and the whole vicinity, from the fossil pectens, nautili, and 

 terebratulae, and extensive mineral veins and vegetable products, that claim attention on 

 every hand, is more than ordinarily interesting. Above the junction of the Claro, the valley 

 has again a northerly direction for five leagues ; and thence from the silver mines of Chapilca, 

 on the right bank, the course is east as far as Quanta, a little triangular valley at the distance 

 of eight miles. This valley, at the confluence of Malpaso creek with the Turbio, is surrounded 

 on all sides by enormous vertical rocks, giving the most out-of-place aspect to the cluster of 

 fruit-trees in its midst. Although more than 3,900 feet above the sea, its climate is so preco- 

 cious that the second crop of figs matures before the first ripens at Coquimbo. From Guanta 

 2 



