Creation of the Teton Landscape: The Geologic Story of Grand Teton National Park
View west toward Grand Teton on skyline. Hedrick’s Pond surrounded by “knob and kettle” topography is in foreground, tree-covered Burned Ridge moraine is in middle distance, and extending from it to foot of mountains is gray flat treeless glacial outwash plain. National Park Service photo by W. E. Dilley.
View west up Cascade Canyon, with north face of Mt. Owen in center. National Park Service photo by H. D. Pownall.
To Fritiof M. Fryxell, geologist, teacher, writer, mountaineer, and the first ranger-naturalist in Grand Teton National Park.
All who love and strive to understand the Teton landscape follow in his footsteps.
By J. D. LOVE AND JOHN C. REED, JR. U.S. Geological Survey
Library of Congress Catalogue Card No. : 68-20628 ISBN O-931895-08-1
1st Edition 1968
1st Revised Edition 1971
Reprinted 1979 Reprinted 1984 Reprinted 1989
Grand Teton Natural History Association Moose, Wyoming 83012
Geology is the science of the Earth—the study of the forces, processes, and past life that not only shape our land but influence our daily lives and our Nation’s welfare. This booklet, prepared by two members of the U.S. Geological Survey, discusses how geologic phenomena are responsible for the magnificent scenery of the Teton region.
Recognition of the complex geologic history of our Earth is vital to the enjoyment and appreciation of beautiful landscapes and other natural wonders, to the planning of our cities and highway systems, to the wise use of our water supplies, to the study of earthquake and landslide areas, to the never-ending search for new mineral deposits, and to the conservation and development of our known natural resources. Who can say, in the long run, which of the many uses of this knowledge is the most compelling reason to seek an understanding of the Earth?
J. D. Love
John C. Reed
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CONTENTS
THE STORY BEGINS
First questions, brief answers
An extraordinary story
An astronaut’s view
A pilot’s view
A motorist’s view
A mountaineer’s view
CARVING THE RUGGED PEAKS
Steep mountain slopes—the perpetual battleground
Rock disintegration and gravitational movement
Running water cuts and carries
Glaciers scour and transport
Effects on Jackson Hole
MOUNTAIN UPLIFT
Kinds of mountains
Anatomy of faults
Time and rate of uplift
Why are mountains here?
The restless land
ENORMOUS TIME AND DYNAMIC EARTH
Framework of time
Rocks and relative age
Fossils and geologic time
Radioactive clocks
The yardstick of geologic time
PRECAMBRIAN ROCKS—THE CORE OF THE TETONS
Ancient gneisses and schists
Granite and pegmatite
Black dikes
Quartzite
A backward glance
The close of the Precambrian—end of the beginning
THE PALEOZOIC ERA—TIME OF LONG-VANISHED SEAS AND THE DEVELOPMENT OF LIFE
The Paleozoic sequence
Alaska Basin—site of an outstanding rock and fossil record
Advance and retreat of Cambrian seas: an example
Younger Paleozoic formations
THE MESOZOIC—ERA OF TRANSITION
Colorful first Mesozoic strata
Drab Cretaceous strata
Birth of the Rocky Mountains
TERTIARY—TIME OF MAMMALS, MOUNTAINS, LAKES, AND VOLCANOES
Rise and burial of mountains
The First Big Lake
Development of mammals
Volcanoes
QUATERNARY—TIME OF ICE, MORE LAKES, AND CONTINUED CRUSTAL DISTURBANCE
Hoback normal fault
Volcanic activity
Preglacial lakes
The Ice Age
Modern glaciers
THE PRESENT AND THE FUTURE
APPENDIX
Acknowledgements
Selected references—if you wish to read further
About the authors
Index of selected terms and features
The GRAND TETON NATURAL HISTORY ASSOCIATION
Transcriber’s Notes