Agriculture
Microbes at the Gas Pump
Cleaning Up Fish Farms
Hungry bug seeks hot meal
Amphibians
Toads
Newts
Salamanders and Newts
Animals
Bee Disease
New Elephant-Shrew
Assembling the Tree of Life
Behavior
Chimpanzee Hunting Tools
Pipefish power from mom
Pain Expectations
Birds
Backyard Birds
Mockingbirds
Cardinals
Chemistry and Materials
The solar system's biggest junkyard
Popping to Perfection
Scientist Profile: Wally Gilbert
Computers
Hubble trouble doubled
Music of the Future
Galaxies on the go
Dinosaurs and Fossils
Fingerprinting Fossils
Watery Fate for Nature's Gliders
Three strikes wiped out woolly mammoths
E Learning Jamaica
Results of GSAT are in schools this week
2014 GSAT Results for Jamaican Kids
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Earth
Earth's Poles in Peril
Snowflakes and Avalanches
Earth Rocks On
Environment
Nanosponges Soak Up Pollutants
Whale Watch
When Fungi and Algae Marry
Finding the Past
A Big Discovery about Little People
Of Lice and Old Clothes
Meet your mysterious relative
Fish
Skates and Rays
Puffer Fish
White Tip Sharks
Food and Nutrition
The Color of Health
Chocolate Rules
Moving Good Fats from Fish to Mice
GSAT English Rules
Subject and Verb Agreement
Whoever vs. Whomever
Who vs. That vs. Which
GSAT Exam Preparation Jamaica
Preparing for the GSAT Exam
Scotiabank Jamaica Foundation Grade Six Achievement Test (GSAT) Scholarships
Ministry of Education Announces 82 GSAT Scholarships for 2010
GSAT Exams Jamaica Scholarships
2014 GSAT Results for Jamaican Kids
GSAT stars reap scholarship glory
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Mathematics
Losing with Heads or Tails
42,000 students will sit for the GSAT Exam in two weeks
Math Naturals
Human Body
A New Touch
A Long Haul
Tapeworms and Drug Delivery
Invertebrates
Flatworms
Crabs
Insects
Mammals
Caribou
Hares
Elephants
Parents
The Surprising Meaning and Benefits of Nursery Rhymes
Expert report highlights the importance to parents of reading to children!
What Not to Say to Emerging Readers
Physics
Road Bumps
Project Music
Electric Backpack
Plants
Stalking Plants by Scent
Underwater Jungles
Flower family knows its roots
Reptiles
Geckos
Snapping Turtles
Caimans
Space and Astronomy
Super Star Cluster in the Neighborhood
Pluto's New Moons
Cool as a Jupiter
Technology and Engineering
A Light Delay
Are Propellers Fin-ished?
Riding Sunlight
The Parts of Speech
What is a Noun
Problems with Prepositions
Pronouns
Transportation
Flying the Hyper Skies
Reach for the Sky
Middle school science adventures
Weather
Earth's Poles in Peril
A Change in Climate
Arctic Melt
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™