Searching for the Source
The first published discussion of the source of the Rio Amazonas appears
in 1641. Father Cristobal de Acuna's New Discovery of the Great River
of the Amazons suggests that rivers in three of the kingdoms within
the Viceroyalty of Peru were possible sources of the Amazon: the Napo
in Quito, the Caqueta in New Granada, and the Maranon in Peru. By
the mid-nineteenth century improved maps of the eastern slopes of the
Andes showed the Rio Ucayali to be longer than the above rivers. In the 1930s
a Peruvian Army survey identified the Ucayali's longest tributary, the
Tambo-Ene-Apurimac system, as the source of the Amazon. In 1971 National
Geographic writer and photographer Loren McIntyre used airphotos and
map sheets to identify the Hornillos-Challamayo-Lloqueta as the longest
tributary system of the Rio Apurimac. From the summit of Nevado Mismi McIntyre
and Victor Tupa, nomenclature director for Peru's Servicio Geodesico Interamericano,
observed a perennial tarn on the mountain's north slope just above Quebrada
Carahuasanta. Using air photos and maps, Tupa determined the coordinates
of the tarn and designated it Laguna McIntyre.
Rio Lloqueta
The Lloqueta lies within the Cadena de condos volcanicos part of the high
Puna plateau. While the Andes are dominantly compressive, this area
is characterised by neutral or extensional stresses. Soils within
the valley are primarily alluvium and colluvium originating from late Cretaceous
to early Tertiary volcanic rocks. Vegetation cover is sparse, with
only short grasses and mosses lying near drainage channels. Land use
in the Rio Lloqueta basin is seasonal and limited to grazing alpacas and
llamas on the grasses near the quebradas. During the dry season herders
occupy six remote estancias in the basin, and the animals are corralled
at the estancias during the night. The pass above the Lloqueta is
used as a trade route between Cailloma, a mining center to the north,
and Lari, a pueblo in the Rio Colca valley.
For more information, please contact:
Andrew K. Johnston
Smithsonian Institution
National Air and Space Museum
Center for Earth and Planetary Studies