Agriculture
Middle school science adventures
Vitamin D-licious Mushrooms
Protecting Cows—and People—from a Deadly Disease
Amphibians
Tree Frogs
Frogs and Toads
Salamanders and Newts
Animals
Tool Use Comes Naturally to Crows
No Fair: Monkey Sees, Doesn't
Missing Moose
Behavior
Between a rock and a wet place
Fighting fat with fat
Pollution at the ends of the Earth
Birds
Dodos
Tropical Birds
Swans
Chemistry and Materials
Putting the Squeeze on Toothpaste
Toxic Dirt + Avian Flu = Science Fair Success
The newest superheavy in town
Computers
Batteries built by Viruses
Fingerprint Evidence
Secrets of an Ancient Computer
Dinosaurs and Fossils
A Big, Weird Dino
Supersight for a Dino King
Dinosaur Dig
E Learning Jamaica
Results of GSAT are in schools this week
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
2014 GSAT Results for Jamaican Kids
Earth
Killer Space Rock Snuffed Out Ancient Life
Easy Ways to Conserve Water
Rocking the House
Environment
Hazy with a Chance of Sunshine
Plastic Meals for Seals
A Stormy History
Finding the Past
A Big Discovery about Little People
Settling the Americas
Oldest Writing in the New World
Fish
Perches
Parrotfish
Marlin
Food and Nutrition
Allergies: From Bee Stings to Peanuts
Healing Honey
Eat Out, Eat Smart
GSAT English Rules
Pronouns
Subject and Verb Agreement
Adjectives and Adverbs
GSAT Exam Preparation Jamaica
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
The Annual GSAT Scholarships
GSAT Exams Jamaica Scholarships
GSAT stars reap scholarship glory
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Scholarship
GSAT Mathematics
Detecting True Art
Setting a Prime Number Record
GSAT Mathematics Quiz, Teaching Math, teaching anxiety
Human Body
Don't Eat That Sandwich!
Music in the Brain
Sea Kids See Clearly Underwater
Invertebrates
Octopuses
Ants
Black Widow spiders
Mammals
Mongooses
German Shepherds
Wildcats
Parents
How children learn
What Not to Say to Emerging Readers
Expert report highlights the importance to parents of reading to children!
Physics
Invisibility Ring
Echoes of a Stretched Egg
Black Hole Journey
Plants
Getting the dirt on carbon
Cactus Goo for Clean Water
Sweet, Sticky Science
Reptiles
Caimans
Pythons
Chameleons
Space and Astronomy
A Puffy Planetary Puzzle
Phantom Energy and the Big Rip
Intruder Alert: Sweeping Space for Dust
Technology and Engineering
Switchable Lenses Improve Vision
Drawing Energy out of Wastewater
Musclebots Take Some Steps
The Parts of Speech
Adjectives and Adverbs
What is a Preposition?
Problems with Prepositions
Transportation
Charged cars that would charge
Are Propellers Fin-ished?
Seen on the Science Fair Scene
Weather
Watering the Air
A Change in Climate
Warmest Year on Record
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™