Agriculture
Protecting Cows—and People—from a Deadly Disease
Treating peanut allergy bit by bit
Getting the dirt on carbon
Amphibians
Frogs and Toads
Poison Dart Frogs
Salamanders
Animals
Thieves of a Feather
Helping the Cause of Macaws
Clone Wars
Behavior
World’s largest lizard is venomous too
Pollution at the ends of the Earth
GSAT Mathematics Quiz, Teaching Math, teaching anxiety
Birds
Robins
Hawks
Kookaburras
Chemistry and Materials
Watching out for vultures
Revving Up Green Machines
The newest superheavy in town
Computers
The science of disappearing
Seen on the Science Fair Scene
A Light Delay
Dinosaurs and Fossils
Meet your mysterious relative
Fossil Fly from Antarctica
Dino-Dining Dinosaurs
E Learning Jamaica
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
Earth
A Volcano's Deadly Ash
Deep History
Hot Summers, Wild Fires
Environment
Catching Some Rays
A Vulture's Hidden Enemy
Bald Eagles Forever
Finding the Past
Preserving Ancient Warrior Paint
Oldest Writing in the New World
Words of the Distant Past
Fish
Sting Ray
Seahorses
Saltwater Fish
Food and Nutrition
Allergies: From Bee Stings to Peanuts
The mercury in that tuna
Sponges' secret weapon
GSAT English Rules
Problems with Prepositions
Subject and Verb Agreement
Who vs. That vs. Which
GSAT Exam Preparation Jamaica
GSAT stars reap scholarship glory
Ministry of Education Announces 82 GSAT Scholarships for 2010
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Exams Jamaica Scholarships
GSAT stars reap scholarship glory
2014 GSAT Results for Jamaican Kids
Results of GSAT are in schools this week
GSAT Mathematics
Math and our number sense: PassGSAT.com
Secrets of an Ancient Computer
Math Naturals
Human Body
A Long Trek to Asia
Football Scrapes and Nasty Infections
What the appendix is good for
Invertebrates
Daddy Long Legs
Butterflies
Camel Spiders
Mammals
Doberman Pinschers
Wombats
Sphinxes
Parents
Expert report highlights the importance to parents of reading to children!
Choosing a Preschool: What to Consider
How children learn
Physics
IceCube Science
Dreams of Floating in Space
Project Music
Plants
When Fungi and Algae Marry
Cactus Goo for Clean Water
Plants Travel Wind Highways
Reptiles
Asp
Caimans
Snapping Turtles
Space and Astronomy
Galaxies Divide Sharply Along Color Lines
World of Three Suns
Ready, Set, Supernova
Technology and Engineering
Shape Shifting
A Clean Getaway
Searching for Alien Life
The Parts of Speech
Problems with Prepositions
Adjectives and Adverbs
What is a Noun
Transportation
Robots on the Road, Again
Middle school science adventures
Troubles with Hubble
Weather
Arctic Melt
In Antarctica watch the heat (and your step)
Weekend Weather Really Is Different
Add your Article

Deep History

The Grand Canyon is one of nature's most majestic and impressive places. The gorge is enormous, measuring 277 miles (446 kilometers) long and up to a mile (1.6 km) deep in some places. The Colorado River runs through the middle of it. But how old is it? Now, scientists have collected new clues about the canyon's ageThe canyon's walls are full of caves that contain lumps of minerals called mammillaries. These mound-shaped lumps usually form just below the surface of pools that are full of minerals. Water levels in such pools can drop when, for example, a change in climate occurs or the Earth's crust shifts. The mammillaries remain, even when the water level drops. Scientists can analyze concentrations of metals inside the mounds to figure out when their pools went dry. Carol Hill, a geologist at the University of New Mexico in Albuquerque, and colleagues studied mammillary formations in nine caves near the Grand Canyon. Most of these caves lie within a few miles of the Colorado River, which carved the rocky gorge. All the sampled mounds were within three-quarters of a mile (1.2 km) above the river's current level. Analyses of the mounds in the western region of the Grand Canyon suggest that 17 million years ago the level of groundwater in the area was about 3,800 feet (1,160 meters) higher than it is today. By 7.6 million years ago, the water had dropped to 3,050 feet above the river's current level. About 2 million years ago, the water was only 390 feet (120 m) higher than it is today. Over that time, water levels dropped as the river carved deeper into the canyon's floor. In the eastern region of the Grand Canyon, analyses suggest that the river's carving action started much later but took place far more quickly. In that area, the groundwater level (and probably the river level) dropped almost as far as it did on the western side, 3,000 feet (920 m), but in only one-fifth the time—just the past 3.7 million years. Together, these data suggest that the Colorado River began carving the Grand Canyon at its western end. Later, the process appears to have continued upstream.—Emily Sohn

Deep History
Deep History








Designed and Powered by HBJamaica.com™