The Geologic Story of National Park

Many national parks were established to protect significant geological features and landforms that frame the natural and cultural heritage of America.

Park geological features include the world–renowned sculptured depths of Grand Canyon National Park, the ancient fossils of Dinosaur National Monument, the longest recorded cave system in the world at Mammoth Cave National Park, the greatest density of arches in the world in Arches National Park, the world’s largest and most colorful collections of petrified wood at Petrified Forest National Park, and over half of the known geysers in the world in Yellowstone National Park.

Scientifically important fossil deposits are found in 243 parks, 81 parks contain 4,900 known caves, and another 40 parks have known karst systems. Ninety–seven parks protect 7,500 miles of shoreline, 52 parks contain geothermal systems, 38 parks have volcanoes as a major feature, and 37 have active glacial features. Park museum collections have more than 35,000 geological specimens and nearly 475,000 paleontological specimens.

Big Bend National Park © Rex Vogel, all rights reserved

Big Bend National Park © Rex Vogel, all rights reserved

Big Bend National Park is a special place to study geology. The rocks are clearly exposed, thanks to sparse vegetation and recent erosion. A remarkable array of geologic processes are displayed here, from volcanoes and landslides to fossils and flashfloods. The abundance, diversity, and complexity of visible rock outcrops is staggering, especially to first-time observers.

Twenty seven million years ago a volcanic eruption of immense proportions shook the land around Chiricahua National Monument. One thousand times greater than the 1980 eruption of Mount St. Helens, the Turkey Creek Caldera eruption eventually laid down two thousand feet of highly silicious ash and pumice. This mixture fused into a rock called rhyolitic tuff and eventually eroded into the spires and unusual rock formations of today.

Called the “Land of the Standing-Up Rocks” by Chiricahua Apaches and later the “Wonderland of Rocks” by pioneers, this northwest corner of the Chiricahua Mountains harbors towering rock spires, massive stone columns, and balanced rocks weighing hundreds of tons that perch delicately on small pedestals.

Chiricahua National Monument © Rex Vogel, all rights reserved

Chiricahua National Monument © Rex Vogel, all rights reserved

Grand Canyon National Park attracts the attention of the world for many reasons, but perhaps its greatest significance lies in the geologic record that is so beautifully preserved and exposed here. The rocks at Grand Canyon are not inherently unique; similar rocks are found throughout the world. What is unique about the geologic record at Grand Canyon is the great variety of rocks present, the clarity with which they’re exposed, and the complex geologic story they tell.

Grand Canyon is unmatched throughout the world in the incomparable vistas it offers to visitors on the rim. Somehow “Grand” does not tell how truly incomprehensible this canyon is.

Joshua Tree National Park encompasses some of the most interesting geologic displays found in California’s deserts. Rugged mountains of twisted rock and exposed granite monoliths testify to the tremendous earth forces that shaped and formed this land. Arroyos, playas, alluvial fans, bajadas, pediments, desert varnish, granites, aplite, and gneiss interact to form a giant desert mosaic of immense beauty and complexity.

Grand Canyon National Park © Rex Vogel, all rights reserved

Grand Canyon National Park © Rex Vogel, all rights reserved

Explore cinder cones, lava tube caves, sandstone bluffs, and hiking trails at El Malpais National Monument. Wildlife abounds in the open grasslands and forests. While some may see a desolate environment, people have been adapting to and living in this extraordinary terrain for generations.

Sandstone Bluffs overlooks millions of years of geologic history, from the 200-million year-old sandstone formed by ancient seas, to the 3000 year-old lava that borders the bluffs. Sandstone Bluffs offers an accessible viewing point of the lava flows and lands surrounding El Malpais.

You know at once why this park is called Pinnacles. You face spires and crags that bear no resemblance to the surrounding smooth, round hills. Abruptly, the pinnacle rock formations dominate the scene. These rocks are the remains of an ancient volcano. Or rather they are part of the remains, for the rest of this volcano lies 195 miles to the southeast.

El Malpais National Monument © Rex Vogel, all rights reserved

El Malpais National Monument © Rex Vogel, all rights reserved

Worth Pondering…

There is nothing permanent except change.

—Heraclitus, ancient Greek philosopher

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