Salty water then circulated downward until reaching depths where chemical and temperature conditions were just right for metals picked up by the water in deep parts of the basin to precipitate out to form giant deposits, anywhere from meters to 10 kilometers below the then-surface. The key ingredient was the depth of the lithosphere.
Where it is thickest, little heat from the hot lower mantle rises to potential near-surface ore-forming zones, and where it is thinnest, a lot of heat gets through. The kilometer boundary seems to be Goldilocks zone for creating just the right temperature conditions, as long as the right chemistry also is present.
But in many cases, deposits starting as far down as a kilometer could probably be mined economically, and these would "almost certainly be taken out via much less disruptive shafts," said Hoggard.
The study promises to open exploration in so far poorly explored areas, including parts of Australia, central Asia and western Africa. Based on a preliminary report of the new study that the authors presented at an academic conference last year, a few companies appear to have already claimed ground in Australia and North America. But the mining industry is notoriously secretive, so it is not clear yet how widespread such activity might be.
Materials provided by Earth Institute at Columbia University. Original written by Kevin Krajick. Note: Content may be edited for style and length.
Science News. Journal Reference : Mark J. Hoggard, Karol Czarnota, Fred D. Richards, David L. Smelting involves heating up the ore until the metal becomes spongy and the chemical compounds in the ore begin to break down. This process releases oxygen from the ore, one of the most common impurities in the metal.
The facility used to smelt the iron is referred to as a bloomer. There, a blacksmith burns charcoal with iron ore and a good supply of oxygen. The carbon in the charcoal combines with the oxygen to create carbon dioxide and carbon monoxide. These gases are carried away, leaving behind the heavier elements.
The metal never gets hot enough to melt completely, just hot enough to become a spongy mass containing iron and silicates. Heating and hammering this mass forces impurities out and mixes the glassy silicates into the iron metal to create wrought iron. Identified deposits contain an estimated 2. This would fit into a cube measuring meters on a side. It is also estimated that undiscovered resources contain about 3.
IntroductionEach mineral commodity chapter of the edition of the U. Geological Survey USGS Mineral Commodity Summaries MCS includes information on events, trends, and issues for each mineral commodity as well as discussions and tabular presentations on domestic industry structure, Government programs, tariffs, 5-year salient statistics The U.
Geological Survey completed the first-ever global assessment of undiscovered copper resources for the two most significant sources of global copper supply: porphyry copper deposits and sediment-hosted stratabound copper deposits. The geology-based study identified areas for undiscovered copper in 11 regions of the world. The economic growth of an industrialized nation such as the United States requires raw materials for construction buildings, bridges, highways, and so forth , defense, and processing and manufacture of goods and services.
Since the beginning of the 20th century, the types and quantities of raw materials used have increased and changed Mobile phones and other high-technology communications devices could not exist without mineral commodities.
More than one-half of all components in a mobile device—including its electronics, display, battery, speakers, and more—are made from mined and semiprocessed materials mineral commodities. Some mineral commodities can be recovered as In , China accounted for 10 percent of world copper consumption. By , China accounted for about 49 percent of world copper consumption.
This change has affected global copper and copper scrap prices, the sources of copper supply, and U. This report considers changes to the copper and copper scrap Using a geology-based assessment methodology, the U.
Geological Survey estimated a mean of 3, million metric tons Mt of undiscovered copper among tracts around the world. Annual U. The USGS assessed undiscovered copper in two deposit types that account for about 80 percent of As one of a series of reports that describe the recycling of metal commodities in the United States, this report discusses the flow of copper from production through distribution and use, with particular emphasis on the recycling of industrial scrap new scrap1 and used products old scrap in the year This materials flow study includes a Copper was one of the first metals ever extracted and used by humans, and it has made vital contributions to sustaining and improving society since the dawn of civilization.
Copper was first used in coins and ornaments starting about B. The discovery that In the language of economic geology, Earth materials are classified as metallic ores, fuel minerals, gemstones, and industrial minerals. Most people know that metallic ores yield shiny, conductive, ductile elements such as copper, iron, or gold.
Most understand that energy-producing coals constitute a fuel mineral. Likewise, dazzling rubies and Geological Survey USGS provides information to the public and to policy-makers concerning the current use and flow of minerals and materials in the United States economy. The USGS collects, analyzes, and disseminates minerals information on most nonfuel mineral commodities.
This USGS digital database is an online compilation of This teacher's guide defines what a mineral deposit is and how a mineral deposit is identified and measured, how the mineral resources are extracted, and how the mining site is reclaimed; how minerals and mineral resources are processed; and how we use mineral resources in our every day lives. We also use third-party cookies that help us analyze and understand how you use this website.
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