“Is it still shrinking?” gasped the old prospector.
“Sure thing! But not so fast that you will ever know the difference in your lifetime. It only shrinks at times; then the earth’s surface wrinkles into mountain ranges.”
“How many times has that been, sixteen?” suggested Ace.
“We’ll come to that. As I was going to say, while the earth was so hot, it kept boiling, as it were, inside, and the molten matter kept breaking through the cold outer shell in volcanoes, as the heat rose to the surface.”
“Thet sure must have been hell,” laughed the old man.
“As the cold crust was churned into the hot interior, of course it melted and expanded, and that caused more volcanoes, and so on in a vicious circle, till finally, by the end of the Formative Era, so called, the rock that contained more heavy minerals sank to the lower levels, while the lighter ones rose as granite.”
“Gee!” said Ted, “I’d have called granite heavy.”
“Not so heavy as the specimens of basic rock we’ll find. Well, in this Formative Era our atmosphere, and the hydrosphere or oceanic areas were being formed, along with the granite continents. But while we are on the subject, I hope you boys will some day see The Valley of Ten Thousand Smokes, in Alaska, where the earth is still boiling so close to the surface that you have to watch your step or you’ll break through into––”
“The Hot Place?” laughed Pedro.
“Literally, yes.”