7,846 results
7,846 results for: Geology
- Planetary Science
Bone-dry Mars?
The presence of large amounts of olivine, a mineral that undergoes rapid chemical transformation when exposed to liquid water, argues against ancient oceans or lakes on Mars.
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19347
I read and reread this article, hoping to find an explanation of where all those sediments have gone. From appearances, they surely all haven’t been deposited in the Gulf of California. Where else? Does anyone have any satisfying theories? Allen Glenn Abilene, Texas Sediments from the erosion of the Grand Canyon have ended up in […]
- Earth
National Atlas
Provided by the U.S. Department of the Interior, this Web site features an interactive map generator that allows users to view and download custom maps of the United States. The maps access a database that includes information about the nation’s agriculture, biological resources, climate, environment, geology, history, transportation, watersheds, population distribution, county boundaries, and other […]
- Earth
The Making of a Grand Canyon
Carving this beloved hole in the ground may not have been such a long-term project.
- Plants
Smokey the Gardener
Wildfire smoke by itself, without help from heat, can trigger germination in certain seeds, but just what the vital compound in that smoke might be has kept biologists busy for years.
- Earth
Meteorite Crater
The Barringer Crater in Arizona is one of the more famous geological sites on Earth. This Web site recounts the history and science of the crater’s formation 50,000 years ago and provides information about its discovery, its purchase by D.M. Barringer, and its current status. Go to: http://www.barringercrater.com/
- Earth
Lake Retreat: African river valley once hosted big lake
The valley of the White Nile in Africa may long ago have held a shallow lake that sprawled 70 kilometers across and stretched more than 500 km along the river.
- Earth
Undersea Mountain Descent
Join an international expedition in exploring an underwater mountain in the middle of the Atlantic Ocean. Twice-weekly dispatches highlight the scientific team’s findings for the duration of the expedition from Nov. 14 to Dec. 14. Hosted by the Scripps Institution of Oceanography, the expedition’s Web site also includes colorful diagrams illustrating various geological concepts and […]
- Earth
Long Ride West: Many western sediments came from Appalachians
Much of the material in several thick layers of sandstone in the western United States originated in the Appalachians.
- Humans
Science News of the Year 2004
A review of important scientific achievements reported in Science News during the year 2004.
- Earth
Study gives new answer for muddy mystery
Geologists provide evidence that quartz silt in ancient seabeds doesn't come from eroded land rocks, but rather from the dissolved skeletons of tiny primitive creatures, possibly altering the fossil record and changing models of prehistoric climate and ocean geography.
- Earth
Blasts from the Past: Orbiting radar spots old nuclear-test sites
A technique that analyzes satellite images to detect subtle ground motions often can perceive subsidence over underground nuclear-test sites, sometimes even if those tests occurred decades ago.
