Earth Science: A Scientific History of the Solid Earth (Discovering the Earth)
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It describes how scholars, explorers, and mapmakers measured the Earth and mapped its surface. It tells of their speculations about what lies beneath the surface, how mountains rise and ocean basins fill. It explains how scientists came to understand the meaning of fossils, how they discovered the age of the planet, and, more recently, how the theories of seafloor spreading, continental drift, and plate tectonics developed.
ancient times there were rich alluvial deposits in Lydia, Persia, India, China, and the lands around the Aegean. The earliest known source of gold was on the Black Sea coast near the modern city of Varna, in Bulgaria, and the metal was certainly being used in Egypt and Mesopotamia by about ... By ... rich people were using gold rings to pay their bills. Gold was the first metal to be exploited. There has never been enough gold to satisfy the need or greed of the powerful, so
the ore, and the products of the reaction float on top of the molten metal as a slag. The Timna smelters introduced the technique of “tapping,” by tilting the container and pouring off the slag while allowing the copper to accumulate at the bottom. When the slag cooled, metallic iron would have been found mixed with the other ingredients. In the s the American archaeologist Nelson Glueck (–) suggested that Timna Valley might have been the site of King Solomon’s Mines, but this has not
carbon from the charcoal, ash from the fire, and other minerals Native Metals and Metal Ores from the ore would form a mixture called slag. Slag permeated the bloom. The furnace was then broken open and the white-hot bloom removed, and while still hot, it was hammered to expel as much of the slag as possible. Hammering also converted the bloom into a mass of wrought iron. Iron has many uses, but it is too soft and brittle to make useful tools. By about ... East African metalworkers had
the Harz Mountains of Germany, the Vosges and Brittany in France, and Westmorland in northern England, which he found continued in the Allegheny and Ozark Mountains in the eastern and southeastern United States. He also believed that the Pyrenees and European Alps were part of the same mountain system. Clearly all of these mountains had formed at the same time within a single event, and Élie de Beaumont suggested that episodes of mountain building—now called orogenies—coincided with gaps in the
buildings, road junctions, and traffic lights are landmarks. In other parts of the world the landmarks may be harder to recognize, at least for someone unfamiliar with the landscape. Traditionally, Inuit families hunted for food across the frozen sea or inland through the tundra. In the Sahara nomadic Bedouin would traditionally spend the winter rainy season driving their livestock from place to place in search of good pasture. Mongolian nomads follow a regular routine that takes them from one