Agriculture
Microbes at the Gas Pump
Watching out for vultures
Seeds of the Future
Amphibians
Salamanders
Frogs and Toads
Salamanders and Newts
Animals
Copybees
Sleep Affects a Bird's Singing
Clone Wars
Behavior
Body clocks
Lightening Your Mood
Bringing fish back up to size
Birds
Nightingales
Cardinals
Kiwis
Chemistry and Materials
Watching out for vultures
The Buzz about Caffeine
Bandages that could bite back
Computers
Computers with Attitude
Galaxies far, far, far away
Graphene's superstrength
Dinosaurs and Fossils
The Paleontologist and the Three Dinosaurs
Dino Takeout for Mammals
Digging Dinos
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
Hot Summers, Wild Fires
Arctic Algae Show Climate Change
In Antarctica watch the heat (and your step)
Environment
Antarctica warms, which threatens penguins
Pumping Up Poison Ivy
Ready, unplug, drive
Finding the Past
A Long Haul
Big Woman of the Distant Past
Writing on eggshells
Fish
Skates and Rays
Dogfish
Freshwater Fish
Food and Nutrition
Allergies: From Bee Stings to Peanuts
Making good, brown fat
Chew for Health
GSAT English Rules
Capitalization Rules
Whoever vs. Whomever
Finding Subjects and Verbs
GSAT Exam Preparation Jamaica
10 Common Mistakes When Preparing for the GSAT Math Test
The Annual GSAT Scholarships
How are students placed after passing the GSAT exam
GSAT Exams Jamaica Scholarships
GSAT stars reap scholarship glory
GSAT Practice Papers | GSAT Mathematics | Maths
GSAT Exam Preparation
GSAT Mathematics
Math is a real brain bender
10 Common Mistakes When Preparing for the GSAT Math Test
How a Venus Flytrap Snaps Shut
Human Body
Sea Kids See Clearly Underwater
What the appendix is good for
Workouts: Does Stretching Help?
Invertebrates
Mussels
Beetles
Scallops
Mammals
Weasels
Sphinxes
Primates
Parents
Children and Media
What Not to Say to Emerging Readers
How children learn
Physics
One ring around them all
Strange Universe: The Stuff of Darkness
Black Hole Journey
Plants
Cactus Goo for Clean Water
Springing forward
Underwater Jungles
Reptiles
Pythons
Lizards
Tortoises
Space and Astronomy
Older Stars, New Age for the Universe
A Planet's Slim-Fast Plan
A Dead Star's Dusty Ring
Technology and Engineering
Bionic Bacteria
Drawing Energy out of Wastewater
Crime Lab
The Parts of Speech
What is a Verb?
What is a Preposition?
What is a Noun
Transportation
Troubles with Hubble
Charged cars that would charge
Revving Up Green Machines
Weather
The Best Defense Is a Good Snow Fence
Arctic Melt
Either Martians or Mars has gas
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™