Geology Of The Lassen Country PDF Download

"Rough-Hewn Land tells the geologic story of the American West--the story of its rocks, rivers, mountains, earthquakes, and mineral wealth, including gold. It tells it by taking you on a 1000-mile-long field trip across the rough side of the continent from the California coast to the Rocky Mountains. This book puts you on the outcrop, geologic hammer in hand, to explore the evidence for how the spectacular, rough-hewn lands of the West came to be. When North America broke free from Eurasia and Africa some 200 million years ago, it triggered a cascade of violent geologic events that shaped the West we see today. As the west-moving continent crunched across the seabed of the ancient Pacific, islands and assorted pieces of ocean floor collected against its prow to build California--and plant gold there too. Meanwhile, mountains squeezed upward from California to Colorado, and vast quantities of molten rock seeded the crust with precious metals while spewing volcanic fire across the land. Later, the land stretched like an accordion to form the washboard-like Basin and Range province and Great Basin within it, while California began to crackle along the San Andreas fault. Throughout the West today, a near-constant drumroll of earthquakes testifies to a world still reshaping itself in response to the ceaseless movements of the Earth's tectonic plates. Rough-Hewn Land weaves these stories into the human history of the West. As we follow the adventures of John C. Frémont, Mark Twain, the Donner party, and other historic characters, we see how geologic forces have shaped human experience, just as they direct the fate of the West today"--