Geology

Beds of the Potoco Formation form the western limb of the Corque Syncline
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Geology - Corque Syncline

Possibly the largest syncline on Earth, the Altiplano's Corque Syncline measures 15 km deep, 50 km wide, and 300 km long. It is composed of an upward-coarsening succession of distal and proximal fluvial Cenozoic strata. Provenance analyses of these foredeep strata of the Altiplano basinrecord a western basement-arc source (granitic and volcanic clasts) during late Eocene-Oligocene time followed by an eastern Paleozoic provenance (quartzites and sandstones) during latest Oligocene-Miocene time. The reversal in source region represents relative uplift in the Western Cordillera followed by uplift in the Eastern Cordillera. Besides the scale of the structure, there are terrific dewatering structures in fine-grained strata near the base of the eastern limb.

The remarkably flat terrain of the Altiplano, at 3700 m elevation implores important questions about the Bolivian Andes. Why is it so high? (Because of the thick crust beneath it.) Why is it so flat? (It's a huge internally drained basin.) As such, remnants of former streams, lakes, and playas are evident in ancient deposits which house sedimentary structures such as lenticular channels, rip up clasts, ripple marks, and gypsum beds.

Culture - The Altiplano

Culture across the Altiplano involves principally Aymaran people spread out across the wide-open plains. Small, near-deserted towns dot the Altiplano, often many miles apart. Vicunas, llamas, and alpacas roam the flat plains. Occasionally, you spot Bolivians tending their sheep or llamas and can't help but wonder where they are headed or where they came from. Many times the women carry the loads, and the men, if present, will be escorting them on their bikes. Small children accompany the herds on occasion, and many times, the children themselves herd their animals across the landscape. Living conditions across the Altiplano are some of the most extreme in the country. Homes are built from mud (adobe) and rocks and are typically no larger then a two-car garage. Most of the Altiplano is very desolate and witnessing the culture in small towns across the Altiplano is a unique experience. On our route, we met Ayamaran indigenous people in Chuquichambi, and stopped in Challapata - our one chance to purchase llama jerky.

Culture

Friendly Bolivians on their way home near Chuquichambi (More Culture!)

Group Shots

An amazing sunset on our first night camping in Bolivia (More Group Shots!)

Animals

Rare vicunas grazing on the Altiplano (More Animals!)