Hilltops surrounded by farmland in southern Wisconsin turn out to be the eroded remnants of an ancient archipelago. An island in the Yellow Sea where Korean tourists flock is the peak of a flooded mountain rising from a drowned continental shelf. From a mountaintop shrine to Genghis Khan in Inner Mongolia, the silhouette of a Silurian seascape can be spotted. On the shores of Hudson Bay, where polar bears patrol the Arctic tundra, a close look unveils what was a tropical coastline encrusted with corals nearly 450 million years ago.
The geologist Markes E. Johnson invites readers on a journey through deep time to find the traces of ancient islands. He visits a dozen sites around the globe, looking above and below today's waterlines to uncover how landscapes of the past are preserved in the present. Going back 500 million years to the Cambrian through the Pleistocene 125,000 years ago, this book reconstructs how "palaeoislands" appeared under different climatic conditions and environmental constraints. Finding vestiges of prehistoric ecologies, Johnson emphasizes the complexity of island ecosystems and the importance of preserving these significant sites.
Inviting and accessible, this book is a travelogue that takes readers through time as well as space. Islands in Deep Time shares the adventure of exploring striking locations across geologic eras and issues a passionate call for their conservation.
Preface: On the Reality of Time Travel
Acknowledgments
1. How to Listen to a Sky Island with Global Ambition: Climbing Mount Monadnock
2. How an Island Cluster Acquires Its Shape: A Journey in Late Cambrian Time to Wisconsin's Baraboo Archipelago
3. How Islands Trade in Physical Wear and Organic Growth: A Journey in Late Ordovician Time to Hudson Bay's Jens Munk Archipelago
4. How Islands Recall Windward Surf and Leeward Calm: A Journey in Late Silurian Time to Inner Mongolia's Bater Island
5. How Bigger Islands are Broken into Smaller Pieces: A Journey in Late Devonian Time to Western Australia's Mowanbini Archipelago
6. How Softer Islands Dissolve: A Journey in Early Permian Time to the Labyrinth Karst of Western Australia
7. How Islands React to Big Storms: A Journey in Early Jurassic Time to Saint David's Archipelago of Wales
8. How Island Life Aligns with Global Currents: A Journey in Late Cretaceous Time to Baja California's Erendira Islands
9. How Island Life Adjusts to Opposing Shores on Oceanic Islands: A Journey in Middle Miocene Time to the Madeira Archipelago
10. How Volcanic Islands Rise, Fall, and Renew: A Journey in Early Pliocene Time to the Azorean Santa Maria Island
11. How the Youngest Islands Challenge Witness: Journeys in Pleistocene Time to Islands on the African and Pacific Tectonic Plates
12. How Islands Draw Meaning and Obligation: Descending Mount Misen on Japan's Sacred Miyajima
Glossary
Notes
Bibliography
Index
Markes E. Johnson is the Charles L. MacMillan Professor of Natural Science Emeritus at Williams College. His most recent book is Baja California's Coastal Landscapes Revealed: Excursions in Geologic Time and Climate Change (2021).
"Islands in Deep Time is a deep dive into the logic of geology: how vanished land- and seascapes can be conjured back into existence from the raw rock record. All geologists collect old rocks, but Markes Johnson collects entire ancient islands. This book is an exhibit of a dozen particularly fine specimens, which Johnson holds up and rotates so they can be viewed from multiple perspectives."
– Marcia Bjornerud, author of Geopedia: A Brief Compendium of Geologic Curiosities and Timefulness: How Thinking Like a Geologist Can Help Save the World
"Using his lifetime of experience in geology, Johnson illustrates how a landscape can be read as the results of millions of years of geological, biological and climatological processes. A fascinating and imaginative work."
– Henry Hooghiemstra, emeritus professor in the Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam
"Islands in Deep Time will take readers for hikes to the ancient shorelines of these islands, featuring possibly the best descriptions and visualizations of field locations I have ever read.:"
– Gordon Chancellor, coeditor, Charles Darwin's Notebooks from the Voyage of the Beagle
"[A [...] ] geological tour de force."
– Deposits Magazine