General Carrera Lake (Chilean side) or Lake Buenos Aires (Argentine side) is a lake located in Patagonia and shared by Argentina and Chile. Both names are internationally accepted.
The lake has a surface of 1,850 km² of which 970 km² are in the Chilean Aysén del General Carlos Ibáñez del Campo Region, and 880 km² in the Argentine Santa Cruz Province, making it the biggest lake in Chile, and the fourth largest in Argentina. In its western basin, Lake Gen. Carrera has 586 m maximum depth.
The lake is of glacial origin and is surrounded by the Andes mountain range. The lake drains to the Pacific Ocean on the west through the Baker River.
The weather in this area of Chile and Argentina is generally cold and humid. But the lake itself has a sunny microclimate, a weather pattern enjoyed by the few settlements along the lake, such as Puerto Guadal, Fachinal, Mallín Grande, Puerto Murta, Puerto Río Tranquilo, Puerto Sánchez, Puerto Ingeniero Ibáñez and Chile Chico in Chile, and Los Antiguos and Perito Moreno in Argentina.
The area near the coast of the lake was first inhabited by criollos and European immigrants between 1900 and 1925. In 1971 and 1991, eruptions of the Hudson Volcano severely affected the local economy, especially that of sheep farming.
The Argentine side of the lake is relatively easy to access, through a strip of plains that was first used by the Tehuelches, and then by explorer Francisco Moreno. The National Route 40, created in the 1920s, also makes use of it. The Chilean side of the lake has been mostly isolated, and was for years accessed through Argentina, until the creation in the 1990s of the Carretera Austral, which connected it to the rest of Chile, and permitted the expansion of tourism in the area.
A car ferry operates between Puerto Ingeniero Ibáñez and Chile Chico in the Chilean sector of the lake.
The lake is known as a trout and salmon fishing destination.
The Marble Caves is geological formation of unusual beauty. These caves have formed in a pure marble and are bathed in the deep blue water of General Carrera Lake
The Marble Chapel (Capilla de Mármol) is located in the commune of Chile Chico, in Port Calm (Puerto Tranquilo). It is formed by a massive marble peninsula, drilled by the lake, with caves at the level of the water which one enters by boat. You will be able to organize a navigation of half an hour, with one stay of equal duration that is made depending on the conditions of the weather. Sail among shining marble walls polished for the water is something truly unforgettable. These calcium carbonate formations were declared Sanctuary of the Nature (Santuario de la Naturaleza).
The enormous General Carrera Lake is fed by rivers coming from several glaciers of Patagonian Andes.
The ice of glaciers contains small particles and, when the ice melts, many particles remain suspended in the water. This gives an unusual effect – the glacial meltwater is slightly turbid and it refracts the blue part of sunlight. Due to this the water of General Carrera Lake has a distinct blue color.
Caves, caverns, tunnels
Marble is sligthly soluble in water. Thus, when the lake reached its present level, the process of solution started at this level. The marble dissolved faster at the water surface – small seeps through the cracks in the marble made these fractures wider and waves washed away the dissolved material.
Thus, in a few thousand years time (very short time for geological processes) the interaction of the marble and blue water of lake formed a place of bewildering beauty – countless caves, mazes, columns and tunnels in the marble.
Larger, more imposing structures are Marble Cathedral and Marble Chapel. Marble Cathedral (Catedral de Mármol) is a small island at the peninsula but Marble Chapel (Capilla de Mármol) is a small marble island closer to the northern coast. One can stop his boat at one such island and take a walk… under the island, through the mazes and tunnels.