Where are the oldest rocks on Earth found?
Since the ocean floor is being continually regenerated as the continental plates move across the Earths surface, the oldest rocks on the ocean floor are less than 300 million years. In contrast, the oldest continental rocks are 4.5 billion years old. 94. What percentage of the worlds fresh water is stored as glacial ice? About 70 percent. And if you had to replace it all, you’d need 60 years of the entire globe’s rainfall, and then you’d have to figure out a way to freeze it all. 95. What is the largest alpine lake in North America? Lake Tahoe on the California-Nevada border has a 105,000-acre surface, holds 39 trillion gallons of water, and is almost 1,600 feet (488 meters) deep. Fate? 96. Have there always been continents? Not as we know them today. Many scientists figure Earth began as one huge continent — dry as a bone. Water was delivered in comets, the thinking goes, and the oceans developed. Much more recently, all the world’s landmasses were huddled into one supercontinent cal
