Unexplored! Part 18

"So there is room for a lot more."

"Especially as the oceans are growing larger all the time."

"But doesn't the ocean give it back to the land when it leaves these sediments along the sh.o.r.e?"

"Not to any extent, speaking comparatively. But one of the interesting things about the salt in the sea is this: Chemists and geologists estimate that, for the amount of salt in the sea, enough of the original earth crust must have been weathered away to have covered the continents over 6,000 feet high. And that calculation just about fits what we believe to have happened.

"The United States Geological Survey gave out an official statement in 1912 that this country is annually being washed back into the ocean at the rate of two hundred and seventy million tons of matter dissolved in the streams and five hundred and thirteen millions of tons of matter held in suspension in the same streams. That is to say, the oceans every year receive from the surface of the United States seven hundred and eighty-three millions of tons of rock materials.

"That means that, here in this part of the country at least, one hundred and seventy-seven tons per square mile are being washed back each year."

"Gee!" said Ted. "I should think, at that rate, that the continents would have been all washed away long ago."

"Yes, there have been, since geological history began, at least twenty whole mountain ranges as high as the Rockies worn to sea level. Of course the oceans have periodically flooded the margins of the continents at such times, in long troughs where now stand our Appalachian and Rocky Mountain ranges, leaving their deposits.

"In the Rockies there are coa.r.s.e sediments miles deep, together with limestone formed of the ground-up sh.e.l.ls of marine animals of the earlier times. Now think of this!

"If all that stands above sea level in the United States to-day were to be washed into the sea, as it undoubtedly will be, in time,--(but not in our time), the level of the oceans will rise, (just as the level of a half gla.s.s of water rises if you drop in a handful of sand), until--it has been estimated--everything under six hundred and fifty feet above sea level will be inundated. That means that probably half of the continent would be under water. It has been so in times past, and it will be again.

In fact, in the age of reptile dominance, (the Cretaceous Period), when the earth was just beginning to be peopled with birds and flying reptiles, and the first, primitive mammals,--the Atlantic flowed straight from what is now the Gulf of Mexico, through what is now the Rocky Mountain Region, and through the Eastern part of Alaska, to the Arctic.

That left one strip of land that reached along what is now the Pacific Coast, clear from the Isthmus of Panama to the Aleutian Islands and straight across to Siberia. The Northern part of the Atlantic Coast formed another land area, broken by the fresh water bodies of America and Canada and in one with a strip of land that extended across Greenland to Europe.

"It is pretty well established, in fact, that the United States has been more or less flooded by warm, shallow marine waters at least sixteen times since the age of fish dominance began. But not since the age of man!" he hastened to a.s.sure the old prospector, who was beginning to look uneasy.

"Of course these flood times brought a moist, warm climate to the land areas, and life was easy for the then existing animal forms. Then when readjustments in the earth's crust again raised up mountain ranges and the climate became colder and drier, the struggle for existence became more intense, the process of evolution was stimulated, and new forms originated.

"We are living in one of those periods now. The organic world is being stimulated to develop even better bodies, endowed with even more alert brains.

"Life is easiest of all for the inhabitants of the ocean. That is why they have developed so little intelligence."

"Is that why it's such an insult to call any one a poor fish?" grinned Ted.

"An ichthyosaurus?" supplemented Ace.

"As has been said before," Norris took up the thread of his talk, "with a drier climate and soil, comes the need of developing a faster mode of locomotion, for food no longer lies or swims everywhere about, as it did in the ocean, and in the swamps, and tropic humidity. Food and water are scarce, and it is the speediest animal that fulfills his needs. This speediness on his part means that he uses up more energy, and hence needs more food, and he needs to a.s.similate it faster. In other words, it means increased metabolism. This in turn means that he keeps his body at a higher temperature. He needs it too, now, with the increased cold. This results in the development of warm blood, by which the animal can maintain his body warmth regardless of winter cold. If it had not been for conditions that forced certain reptiles to develop warm-bloodedness, we would have no birds or mammals to-day, for as you doubtless know, birds and mammals both were evolved from reptiles."

"I swan!" was all the old prospector could say.

"Yes, the first mammals developed from a reptile known as the cynodont.

Many of these reptiles had long legs and could travel with the body well off the ground. Birds originated from the same reptilian stock as did the dinosaurs. First their hind-legs grew long so that they could run on them,--and you will notice at the Museum how the legs of a dinosaur are joined to the body exactly like a bird's,--then their scales gradually evolved into feathers.

"There is a lot more to it than I can tell you now, but after various ups and downs, dinosaurs became extinct and Nature tried out several kinds of warm-blooded, furry mammals, some of them herbivorous and built for speed to run away from their enemies, some of them swamp-dwelling monsters with heavy legs and small brains, who, slow of movement, relied on horns and other armor and sharp teeth for their defense.

"But there is no end to this subject. I only mean to make the point that it was geological changes that drove the fish to land, and the land animal to higher forms, till finally other geological changes drove man's ancestors down out of the trees." The boys, no less than the old prospector, testifying their interest in the last named operation, he continued.

"When the Alps, the Andes and the Himalayas arose, man's ancestors still lived in trees. But high mountains hold a large part of the moisture of the atmosphere in the form of snow and ice, and at the same time the decreased oceanic areas offer less surface for evaporation. Not only does that mean a drier climate, but the sun's rays pa.s.s more freely through dry air, and the days are hotter, and the heat pa.s.sing freely back through the same dry air at night, the nights are colder. Seasons are more extreme, and ice acc.u.mulates on the mountain tops and around the polar region, precursor of a glacier period. The aridity decreases the amount of forest, and the manlike tree dweller had to descend to the ground to get his living. That necessitated the development of his hind legs for speed, and that speed necessitated his a.s.suming a wholly erect posture. That in turn freed his hands, and he, or the man descended from him, could defend himself by throwing stones at the huge beasts who then peopled the earth. The cold winters necessitated the use of the skins of beasts for clothing, and so on through the list. It was geological necessity that drove man into his higher development.

"Changes of climate and environment, however, are stimulating, even to-day. Statistics show that stormy weather actually increases people's energy."

The next day they pa.s.sed a long crack in a rock slope, which Norris felt sure had been made by an earthquake, perhaps as recent as that of 1906, to judge from the cleanness and newness of it. The crack was no more than a foot or two in width, but in places eight feet deep, they estimated, and along the Western side of it stood a fault scarp, in this case a wall of granite bowlders of various sizes up to four or five feet in height.

"This," p.r.o.nounced the geology man, "is evidently a region overlying subterranean volcanoes, which might even yet build the range higher. I'll bet that kind of mountain building may still be going on around here."

Again and again Norris, or even Ace, had been able to point out, in the record of the rocks, the evidences of the two glacier periods that had helped shape the Sierra Nevada, the earlier one much larger, and enduring longer, as shown by the moraines (or deposits) left behind. The lower end of a canyon would be no wider than the stream that incised it, but the upper portion would have been smoothed into gra.s.sy parks or lakelets on each tread of a giant stairway to the summit of the range.

Rounded water-worn pebbles and cobblestones among a ma.s.s of angular bowlders, left behind by glacier streams, together with an occasional striated pebble, were "sermons in stones" to the geologist.

"Hey, Ted," his chum had challenged him that day, "did you ever see a pirate?"

"Don't know as I did," admitted the ranch boy.

"Then I'll show you one. Climb in," and he prepared to search once more for the Mexicans.

"Show me one! You speak as if they kept them in museums."

"This pirate will be a river. A river pirate,--I mean a pirate river! If I could find the divide just North of Muah Mountain I'd show you where streams are being captured this minute. Cottonwood Creek has already captured one of the tributaries of Mulkey Creek, I hear, and diverted it into an eastward flow, and further captures are likely to be pulled off any time. Isn't it a scandal?"

"I say, Ace," protested his chum, "I've swallowed a lot since we started on this trip, but I'm not so gullible as you seem to think."

"Look here, old kid," said Ace seriously. "It's a fact. Along a divide, a stream flowing one way will divert one flowing the other way into its own channel."

They found a pirate river,--but still no trace of the incendiaries.

However, that merely determined the Senator's son the more.

That night Norris told them the long promised tale of his Alaskan trip.

"Nothing like the Valley of Ten Thousand Smokes has ever been seen by the eye of man," he declared. "If we could take all the other volcanic regions of the world to-day and set them down side by side, they would present less of a spectacle, except, of course, at the time of a dangerous eruption. There has been nothing like it in the memory of man,--though geologists can read from the rocks that such conditions must have existed in past ages. The Mt. Katmai eruption of 1912, one of the most dangerous in history, first attracted attention to this region, and the National Geographic Society has since sent various expeditions to Alaska. It was that way that the Valley came to be discovered, in 1916.

"I happened to be a member of the last expedition."

"Honestly!" the boys exclaimed.

"Yes, and I tell you, boys, when I first looked through Katmai Pa.s.s, it just looked as if the whole valley were full of smoke. Of course it was steam."

"Weren't you afraid of another volcano?" asked the boys, snuggling down ready for a real story.

"No, because with all those vents letting off steam, it must relieve the pressure from below, like so many safety-valves. Two black, gla.s.sy looking lava mountains guard the pa.s.s. The wind on the side of Observation Mountain was blowing so hard it honestly lifted us off our feet at times, and it blew a hail of pumice stone in our faces that literally cut the flesh. Of course we wore goggles.

"Once in the valley, there were certainly all of ten thousand smokes rising from the ground. We were simply speechless, it was such an awesome spectacle."

"I'll bet you were!" breathed Ted.

"Personally, I consider it more wonderful than either the Grand Canyon or the geysers of the Yellowstone. As far as we could see in any direction,--and there seemed to be three arms to the valley,--the white vapor was steaming out of the ground until it mingled with a great cloud that hung between the mountain walls. And we later camped in places where we could keep our food in a hollow of a glacier while we boiled our breakfast in a steam hole, and the ground was almost too warm for comfort."

"Must have been an ideal camping place," said Ace.

"Far from that. Too much danger of breaking through. And then of course there wasn't a tree or a gra.s.s blade anywhere, much less a stick of firewood. But we sure had steam heat at night, and we cooked, in the milder of the fumaroles."

"Wasn't there a lot of gas coming up with the steam?" asked Ace.