A Journey on the Rio Zamora, Ecuador

Abstract

The Andes of Ecuador part into two main parallel ranges, known as the Cordillera Occidental and Cordillera Oriental, united at intervals by transverse ridges of inferior height, designated by the Spanish topographical term of nudos, literally knots.l The southernmost of these is the Nudo de Cajanuma, which forms the divide between Pacific and AmazonAtlantic drainage; some twenty-five miles to the north is the Nudo de Acayana y Guagra-uma; and enclosed between the two and the lateral mountain chains is the Basin of Loja (Hoya de Loja). The opposite inner faces of the two Cordilleras are here physiographically similar, but the outer, or Pacific and Amazon versants, respectively, are in distinct contrast. The former, through the withering action of the hot, dry air currents borne up the Catamayo valley from the desert littoral of Peru, is bare of vegetation, while the latter, under the benign influence of perennial rains, is clothed with dense tropical forest. In the intermontane depression between the two ranges, at an elevation of 2,150 meters (7,053 feet) above sea level,2 stands the town of Loja. Due west of it the isolated and sharply outlined peak of Villonaco (3,220 meters, or 10,560 feet) rises from the relatively low profile of the Cordillera Occidental, forming a dominant feature of the local topography and a widely visible landmark. It is interesting to note that certain neighboring eminences, Fierro-urcu (3,788 meters, or 12,430 feet) and Colambo (3,094 meters, or 10,150 feet), were occupied as trigonometrical stations in the great triangulation carried from Tulcan, on the Colombian frontier, all through Ecuador down to Payta, in Peru, by the French geodetic commission in 1899-1906, in their revision and extension of the work of the academicians Bouguer, La Condamine, and Godin in the eighteenth century for the measurement of an equatorial arc of a meridian.3 The lower slopes of the Cordillera Oriental about the Hoya de Loja are