It has long been believed that the Colorado River began carving the Grand Canyon about 6 million years ago, but a 2012 study suggests that the process began 70 million years ago. In all likelihood, the Grand Canyon started out as a series of smaller canyons 70 million years ago, but the majority of the canyon did not begin to take shape until more recently. This passage shows that .....

MAGNETISM

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Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]

“It has long been believed that the Colorado River began carving the Grand Canyon about 6 million years ago, but a 2012 study suggests that the process began 70 million years ago. In all likelihood, the Grand Canyon started out as a series of smaller canyons 70 million years ago, but the majority of the canyon did not begin to take shape until more recently.” This passage shows that ____

A	major land forms on Earth have formed recently
B	Major land forms on Earth have taken long periods of time to form
C	Either A or B
D	None of the above

Explanation:

Detailed explanation-1: -The Colorado River has been carving away rock for the past five to six million years. Remember, the oldest rocks in Grand Canyon are 1.8 billion years old. The canyon is much younger than the rocks through which it winds.

Detailed explanation-2: -After the top layers of rock (green) eroded away, the Colorado River grew powerful and began to cut its way through the ancient rock, leaving the stunning canyon we see today. By around 6 million years ago, waters rushing off the Rockies had formed the mighty Colorado River.

Detailed explanation-3: -This natural landmark formed about five to six million years as erosion from the Colorado River cut a deep channel through layers of rock. The Grand Canyon contains some of the oldest exposed rock on Earth.

Detailed explanation-4: -Grand Canyon. The Grand Canyon, in the U.S. state of Arizona, is a product of tectonic uplift. It has been carved, over millions of years, as the Colorado River cuts down through the Colorado Plateau.

There is 1 question to complete.

GEOLOGY

EARTH SCIENCE

MAGNETISM