From Stone to Star: A View of Modern Geology

by Claude Allègre

Book Overview

From Stone to Star chronicles one of the great scientific adventures of our time. Written by the eminent geochemist Claude All?gre, it offers a fascinating glimpse into the sophisticated isotopic detective work that has established a geologic chronology of the earth and transformed our understanding of its genesis and history. In eighteenth- and nineteenth-century Europe geologists exploring the earth's surface collected fossils and hotly...

• Format: Paperback
• Language: English
• ISBN: 067483867X
• ISBN13: 9780674838673
• Release Date: March 1994
• Publisher: Harvard University Press
• Length: 304 Pages
• Weight: 1.00 lbs.
• Dimensions: 0.7" x 6.2" x 9.3"

Customer Reviews

How were the continents formed?

1. The tectonic plates are created at the ridges and destroyed at the trenches. 2. At the plate boundaries, large amounts of internal energy are dissipated in the form of earthquakes and volcanism. 3. The map of earthquake locations corresponds exactly to the plate boundaries. 4. Volcanoes that border the Pacific have products that are rich in silicon and aluminum than the basalt of the ocean floor. 4. The continents relatively light material rich in potassium silicate and pure silicon and float on the surface of the earth. The continents drift but never plunge into the mantle. The continents are not as old as the oceanic floor. 5. The super continent Gondwanda broke apart about 200 million years ago producing South America, Africa, India, Australia, and Antarctica. The collision between Asia and India, 55 million years ago produced the Tibet-Himalaya zone and sutured two pieces of continent together. 6. Drilling through the horizontal sediments of the basins has brought up samples of folded metamorphosed rock injected with granite. Granite is composed of two minerals, quartz and feldspar. The silicate assemblage concentrates silicon, aluminum, and potassium. The aluminum concentration is twenty times greater and potassium concentrates a thousand times greater than the mantle. 7. Orogensis creates new from old. Orogensis reuses and rejuvenates old pieces of existing continents. Assume the continents were formed 4.5 billion years ago 4.5 billion years ago and each geologic period parts of them are destroyed by erosion (2.7, 3.5, 3.8 billion years old) and transported to the ocean floor in the form of sediments, which were folded, baked, melted, and transformed into granites during orogensis and added to continential crust again. According to this scenario the crust would not have increased in volume over geologic time, it would only have changed its appearance. 8. Strontium 87 is strong in the continental crust and produced from radioactive disintegration of rubidium. The amount of Strontium 87 determines whether the continent is old or new. The result is part is old and part is new. The continents did not form in the primitive earth's history buy gradually very much later on. Pieces of continents have different ages, but the total volume of the continents have been constant throughout geological time. 9. Some Zircons in Australia have been shown to be 4.2 billion years old. Some Zircons were form with granite. No continential granite rocks of the 4.2 billion year age remain. 4.2 billion years ago continents were small. From that time the continents grew steadily. Between 4 to 3 billion years ago, the foundations of North America, Brazil, Africa, India, Central Asia, Scandinavia, Scotland, and part of Central Europe were formed. For the last 500 million years the surface of the continents have grown steadily. Oceans cover 2/3 of the earth and that percentage does not change. For the last 3.8 billion years the net surface area