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Going to Extremes
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Article and Photographs by Carsten Peter

Battling furious winds and rain, a team of cavers explores a bleak island at the bottom of the world.

Get a taste of what awaits you in print from this compelling excerpt.

Inspired by the subpolar weather, I came to think of the island’s marble plateau as a series of rugged glaciers. In reality it is the remnant of a coral reef system laid down between 260 and 315 million years ago in a calm, tropical sea. High on the island, above the forest, sprawled a scene nearly devoid of color—glacier-like rock rendered in a thousand shades of gray, constantly changing before our eyes like a mirage. Fat drops of rain would fall, splattering light gray rock with dark leopard spots or zebra stripes, followed by driving sheets of rain that would slash across the rock and turn it dark and shiny as coal. Then the wind would rise and parts of the exposed rock would dry for a moment, turning white, only to be soaked black again.

It rained like this practically every hour on Madre de Dios, punctuated by occasional bursts of sleet or hail—a furious bombardment of pinpricks that made you want to clap a bucket over your head. The icy wind, which howled in our ears and shook our legs, was so strong that whatever fell from the sky came at us sideways. High-velocity wind and rain had even blasted away the exposed rock and left little wedges of limestone trailing from the leeward side of volcanic rock fragments deposited by glaciers. “This kind of erosion feature has never been seen before,” said our lead geomorphologist, Richard Maire. “These karst islands are like a natural laboratory with a built-in wind tunnel.” He estimates the rate of erosion at six millimeters a century, one of the fastest rates on Earth.

Get the whole story in the pages of National Geographic magazine.

In More to Explore the National Geographic magazine team shares some of its best sources and other information. Special thanks to the Research Division.

Can you imagine being a coral animal deposited in a warm sea millions of years ago only to end up off the cold and wet coast of southern Chile as part of the limestone found on Madre de Dios Island? Plate tectonics, the movement of plates on the Earth’s lithosphere, made such a journey possible.

The limestone found on Madre de Dios formed between 315 and 260 million years ago near the Equator. After formation it was slowly transported on top of what has become the plate below the Pacific Ocean until it collided with the edge of South America, some 230 to 160 millions years ago. Part of the limestone became stuck, or accreted, to South America. Limestone of similar origin has also been found in other places, including the margins of the modern Pacific Ocean in Canada, Japan, and New Zealand. Chilean geologist Constantino Mpodozis explains: “These areas all represent pieces of ancient near-equatorial reef limestone dispersed by the movement of the Pacific Ocean floor and accreted against the bordering continents.”

—Michelle R. Harris

Ultima Patagonia Expedition 2000
Check out the expedition’s website to learn more about their work in southern Chile and to see photos of the landscape and spectacular caves.

Cave Research Foundation
This foundation promotes exploration and documentation of caves and karst areas and aids in conservation and protection of these resources.

Cave and Karst Terminology
Ever wonder what a speleologist does? This site tells you about speleology (the exploration, description, and scientific study of caves and related phenomena) and also defines everything from arthropods (animals found in caves) to the phreatic zone (the zone where voids in the rock are completely filled with water).

The Karst Waters Institute
Find technical information on karst research and caving techniques at this site. The Karst Waters Institute promotes the management of water resources and provides education and training. You can also download a lexicon of cave and karst terminology.

The National Speleological Society
With a library, bookstore, and discussion boards, this organization’s website is a good resource for people interested in protecting, enjoying, and studying caves.


Hudson, Rex A., ed. Chile: a Country Study. Federal Research Division, Library of Congress, 1994.

McEwan, Colin, Luis A. Borrero, and Alfredo Prieto, eds. Patagonia: Natural History, Prehistory and Ethnography at the Uttermost End of the Earth. Princeton University Press, 1997.

Stamp, Sir Dudley, and Audrey Clark. A Glossary of Geographical Terms, 3rd ed. Longman, 1979.

White, William B. Geomorphology and Hydrology of Karst Terrains. Oxford University Press, 1988.


Crouch, Gregory. “Stone Cold Ascent,” National Geographic (March 2000), 96-115.

Amatt, John and others. Voices From the Summit: The World’s Great Mountaineers on the Future of Climbing. National Geographic Books, 2000.

Bangs, Richard. “Torres del Paine,” National Geographic Traveler (October 1999), 136-138.

Chiappe, Luis. “Dinosaur Embryos,” National Geographic (December 1998), 34-41.

Brower, Kenneth. “Chile by Land and Sea,” National Geographic Traveler (September/October 1997), 90-104.

Shreeve, James. “Uncovering Patagonia’s Lost World,” National Geographic (December 1997), 120-137.

Franklin, William L. “Patagonia Puma: The Lord of the Land’s End,” National Geographic (January 1991), 102-113.

“Journey Through Wild, Windswept Patagonia,” National Geographic World (August 1988), 9-12.

Bartlett, Des. “Patagonia’s Wild Shore: Where Two Worlds Meet,” National Geographic (March 1976), 298-321.

Hatcher, J. B. “The Indian Tribes of Southern Patagonia, Tierra del Fuego, and the Adjoining Islands,” National Geographic (January 1901), 12-22.

Hatcher, J. B. “Some Geographic Features of Southern Patagonia, With a Discussion of Their Origin,” National Geographic (February 1900), 41-55.

Hatcher, J. B. “Patagonia,” National Geographic (November 1897), 305-319.


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