The expedition to the Peruvian Andes in 1972 was undertaken to explore and document the little‑known limestone karst regions of central Peru. Motivated by the country’s extensive but largely unexplored limestone formations, the team focused on two major study areas: Pirhuacocha, on the high Andean altiplano at 4,500 m, and Palcamayo, home to the significant cave system of Huagapo. The expedition also carried out reconnaissance at Tingo María, Antacocha, and Callash Punta.
At Pirhuacocha, the team established a high‑altitude base camp to conduct geomorphological mapping, geological sampling, and cave prospecting. The region is dominated by Triassic–Jurassic Pucará Group limestones, overlain by Goyllarisquizga Group sandstones and Cretaceous volcanics. The karst is characterised by dolines, sinkholes, gypsum‑rich horizons, and limited cave development due to complex folding, high joint density, and impurity in parts of the limestone. Although many shakeholes were located, most were choked, and no major cave systems were entered. Hydrologically, the plateau features numerous closed depressions and a major limestone resurgence at Saco, active in the wet season.
The second phase relocated the team to Palcamayo, where the expedition undertook extensive exploration and surveying of Cueva de Huagapo, one of Peru’s largest caves. Huagapo contains over 1 km of river passage, phreatic tunnels, canyons, and decorated chambers. The expedition mapped the full system, lowered the sump, and documented the entrance archaeology. Dye tracing confirmed hydrological links between upstream sinks—particularly Antacocha Cave—and the Huagapo resurgence. The team also explored La Sima de Milpo, a 407 m deep vadose cave giving Peru’s then‑deepest known descent, and surveyed additional caves at Antacocha and Callash Punta.
The expedition contributed geological mapping of a previously undocumented region, insights into high‑altitude karst processes, and detailed cave surveys. Transport, local collaboration, altitude acclimatisation, and health management formed critical operational components of the fieldwork.