The Green World
Page 5
Perhaps thirty seconds after it disappeared, there was a minor convulsion in the neck, a momentarily rising hum from the machinery, and a plug of dirt about two centimeters in diameter and five long was ejected from a port in the center of the drum. This was seized by Lampert and examined briefly, then tossed aside. "The soil is pretty deep," he remarked.
"How far down did that come from?" asked Mitsuitei.
"One meter. That's the sampling interval I've set in it, for now. If it meets anything much harder or easier to penetrate, it will warn me and I'll grab them more frequently." Conversation lapsed while two more samples arrived and were inspected. Then a light flickered on the panel, and Lampert reset one of his knobs; and almost immediately a core of light gray limestone was produced.
"Apparently the same stuff as the cliffs," said Lampert after examining the specimen. "Do you want to go any deeper, or drill a few more holes to get an idea of the contour?"
"How fast will that thing go through limestone?"
"A couple of centimeters per minute. It's too small to pack a real power unit."
"Give it five minutes, just to make sure it isn't a building block."
"Ten centimeters wouldn't give you a whole building block."
"A sample from that far inside one would tell me what I want to know. You rock-chippers don't seem to think that archaeology is a science yet. Let me have that first core, too." Mitsuitei looked confident to the point of being cocky, and Lampert let the mole burrow on. The second core came in due time, and the little man set merrily to work with tiny chips from the two stone cylinders, a pinch of the lowest soil sample which had been acquired, a small comparison microscope and a kit full of tiny reagent bottles. Lampert used the time the tests consumed in reversing the mole and resetting the equipment on a new spot. By the time the little mechanism had gnawed its way once more to rock, Mitsuitei was forced to admit that the formation appeared to be natural.
He did not seem as disheartened by the discovery as might have been expected. He simply waited for more cores, his narrow face reflecting nothing but the utter absorption Lampert knew he experienced whenever a problem arose in his line. In spite of his apparent tendency to jump to conclusions, Takehiko Mitsuitei was an experienced and respected member of his profession. Lampert knew enough about his record to be perfectly willing to accept his instructions for the present.
A series of holes was drilled, from the original position toward one of the "streets" forty yards away from it. After each the archaeologist admitted with perfect cheerfulness that there was nothing inconsistent with the idea that the hill was a perfectly natural formation. He still insisted, however, that the regular lines of trees, reinforced as they were by the undergrowth pattern, required explanation.
Lampert admitted this, but felt that he knew what the explanation would be. After all, volcanic residue is more than likely to contain the trace elements vegetation requires, even on Viridis.
Finally the time came to get verification — or the opposite. The flamethrower had to be used this time, and for several minutes clouds of steam swirled about the men as its blue-white tongue fought the sappy, rain-soaked undergrowth. Then the mole and its controls were wheeled into place, and the little robot once more nosed its way out of sight.
"I don't suppose you want any samples above the regular rock level, do you?" asked Lampert as the machine disappeared.
"I think it would be best if we took them as usual," was the reply. "For one thing, we should try to learn the depth at which the soil composition changes we are at least agreed that it changes in some manner, after all."
"True enough." The geophysicist set his controls, and the process continued — a process familiar now to McLaughlin as well as the scientists, for the guide had caught numerous glimpses of what was going on while he prowled about the work area on self-imposed guard duty.
Mitsuitei took the crumbly soil cores as they came, examined them quickly they were arriving every few seconds — and filed them in numbered compartments in a specimen case he had opened. Detailed stratiography would come later. For some time there was no gross evidence of change in the soil; not, in fact, until his first case had been filled.
"Can you stop that thing for a moment, Rob?" he asked at this point. "I don't want to lose track of these, and will have to hold up while I open a new case."
"All right. I thought you'd want to stop for thought soon anyway "
"Why?"
"Because the mole is nearly four meters down, well below the depth at which we hit bedrock before, and is still in soil."
"Eh? But — but it's still ordinary soil; none of your volcanic ash."
"Tuff had been eroded out of a lot of the joints in the cliffs. There's no reason to expect it to be at the same level as the surrounding rock."
"That's true." Mitsuitei paused in thought for a moment. "If we keel on going straight down, we may just be working into a natural crack, as you say. Might it not be better to drill several holes within a few square yards here, to determine whether it is a narrow joint such as you expect or an actual edge to the rock at this level?"
"Maybe the edge of a roof, eh?" Lampert chuckled, but spoke in a manner which could give no offense. "I can do better than that. Don't need to pull up and start over; simply drill horizontally from where we are now. Shouldn't take long to get dimensions, if that's all you want." He halted the robot momentarily, and from a compartment in the drum removed something like a small theodolite mounting. This he set up on a short tripod over the point where the neck of the mole emerged from the ground, and set a pointer at right angles to the line of tall trees. Then he started the digging again.
V
Four starts in as many different directions and twenty minutes of time showed fairly conclusively that the line of vegetation which had given rise to the "street" theory was growing along a straight crack, apparently a fairly ordinary joint, in the limestone. While several more holes would have to be drilled to prove it, even Mitsuitei was willing to admit that in all probability the remaining lines would be found to be over similar cracks.
"You must admit, though, that the regularity of this joint pattern is pretty unusual," the archaeologist said at length.
"It's far from being unknown," Lampert replied. "I got my first large taste of it in my student days back on Earth. Fly over the mesa country in southwestern North America sometime. Most of the joints there are invisible from a distance, of course; but at the edge of a butte where weathering is most prominent the blocks have frequently started to separate, and the thing looks as though it had been put together from outsize bricks."
"Hmph. Seem to remember something of the sort myself, now that you mention it. I did some digging in that area, too. I shouldn't have connected that sort of country with what we have here, though."
"Different meat; same skeleton," replied Lampert.
"But how about this volcanic ash, or mud, or whatever it is, which at least fills the joints we saw in the cliff? That's not so usual, is it?"
"Not in my experience. But granting the joints and the volcanoes, there's nothing really surprising about it. Incidentally, we don't know that this crack we're standing on has the same filling. We'd better bore down again to make sure. At least we may get some idea of the date of the volcanic action compared to that of the orogeny that tilted the block where we're camped. If there's tuff down here too, it will substantiate the idea that the vulcanism is the older."
"Why? Couldn't ash have settled down here as well as up there at substantially the same time?"
"It could. But I'd bet a fairly respectable sum that the tuff we saw in the canyon was from a mud flow, not a fall of airborne ash. That could hardly have reached the top of the cliffs — actually, the opposite slope of the mountains, where Sulewayo is working — and this area simultaneously."
"Maybe from different eruptions? I get the impression that this world has a slight tendency to produce volcanic fields rather than individual cones or flows."
The core was tuff, apparently identical with that in the cliffs to the east. It even contained fossils.
"I guess this whole dig might as well be taken over by the paleontology department," Lampert commented finally. "I suppose they'll at least want to compare fossils in the tilted and level strata.'
"I suppose so." Mitsuitei was turning the little cylinder over and over in his hand. "Tell me, Rob. what's this little speck of green?"
"Copper salts of one sort or another, I suppose." Lampert was not greatly interested. "A lot of secondary minerals form in and under volcanic detritus. On this world, carbonates like malachite should form quite readily."
"Why should it form in a regular thread like this?"
"You mean a vein? Hard to tell precisely. Varying rates of water seepage, varying degrees of oxygen or carbon dioxide penetration, varying degrees of compactness in the rock where the stuff is formed —"
"I don't mean a vein. This is in a cylindrical body going right through the core from one side to the other, as though there had been a copper wire there originally which had been attacked by soil acids."
"Let's see. You're right. It's hardly an ordinary vein, though your suggestion seems a trifle far fetched. The paleontologists can probably furnish an idea. Maybe a vine or even a worm buried in the mud flow acted as the precipitating agent for copper salts in the subsequent seepage —I've seen beautiful fossils of pyrite which had been formed that way."
"But this shows no trace of structure, except for its exterior shape."
"Isn't a really well preserved structure the exception rather than the rule in fossils?"
"I suppose so. Still, I'd like to know just how far, and which way, this green thread goes. I'd also like to know whether there are dilute copper deposits spread through this rock, which could be concentrated in the way you suggest."
"The first could be learned by taking enough cores. The other would call for some very careful analysis of samples which had been selected with a very sedulous eye kept on the stratigraphy. You know that; you must have done that sort of thing looking for carbon-fourteen samples, at times."
"Yes, I see that. Could you make such analyses here?"
"No, except for the mere presence of copper. The cores would have to go back to a well equipped lab. Still, if you want to get them, it's all right with me. Problems were made to be solved. I'll admit this one doesn't seem very exciting to me, but I can use your data after you finish for work of my own. You should wind up with material for a pretty complete geochemical picture of this neighborhood. Shall I get the cores for you?"
"Yes, please."
"Silly question. All right." The mole was drawn up a short distance, and sent questing downward once more at an angle to the original shaft, branching off a short distance above the level from which the copper deposit had come. Again and again the process was repeated, each time at a slightly different bearing from the central hole; and Mitsuitei examined each core for traces of green. At last he found it, piercing the little cylinder of rock as the other had done; and then, at his suggestion, Lampert reset the mole to get a sample in the opposite direction from the one which had furnished the new specimen.
This also checked positive; and four more samples, taken along the same line at various distances, all did the same.
Apparently the line of green extended for some distance, about parallel both to the surface of the ground and the trend of the joint in which it was buried. Mitsuitei was radiant.
"I'm going down to that level if I have to come back with an expedition of my own! If that's a fossil worm, it's worth getting the whole length anyway — but I don't believe it is. I —"
"That will take a lot of time, you know," Lampert pointed out mildly.
"Certainly I know! Even if I use your fast excavator down to the tuff level, have to do detail work from then on. What of it?"
"Well, the others may have jobs they want to do —"
"Then they can do them! What are we here for, anyway? I thought it was to investigate the past of this planet! Ndomi and Hans are doing that their own way right now. Why can't I? I'm an archaeologist, and I came along to do any archaeological work that presented itself to do; this is the only thing of the sort anyone's seen so far. I know what you're thinking. Maybe you're partly right. I certainly won't bet any money that this thread of green is a fossil telephone wire; but it's as likely to be that as anything else you've suggested, and I'm going down to that level and sift the whole volume. Hans and Ndomi can have any fossils I find if that will make you happier and if one of them says he has no use for fossils he didn't dig himself, I'll make him eat his words. I can identify, locate and report on anything that turns up in a rock as well as any of those jigsaw-puzzle people; and I can do it in mud, too, which is more than any of them could manage."
"Don't get hot under the collar. If you can help it on this planet. You sound as though one of the boys had been giving you a lecture on the importance of knowing what strata a given series of specimens represent."
"Not one of our boys — they have a little more sense. But there was a young paleontologist when I was covering the Antares worlds whose memory still makes my blood pressure go up. Never mind me; that's not important. But I want to make this dig."
"It will tie up machines, however freely we can spare time," Lampert said slowly. "I'll tell you: how about this? We spend the rest of the day getting cores from other points along these cracks. For one thing, we ought to know more about the structure of the hill, and for another, we might find more of your `wires.' After all, the chance of our hitting the only one around is pretty remote. I can't quite see a single dropped piece of copper wire showing up in the first two days of a project like this."
"I neither said nor implied that this should be the only piece. I don't doubt for a moment that there are others, whether they are wires or worms."
"Sorry. Well, we take these cores back to camp this evening, together with any others we find of the same sort, and let Hans and Ndomi look them over. If they don't turn out to be something that the boys recognize and can classify right off the bat, we come back tomorrow with all the digging machinery you want, and dig until you either find all you want, satisfy yourself that there's nothing here or find something which obviously requires more specialized attention than we can give it. All right?"
"Nothing could be fairer. Let's go?"
The discussion in camp that evening was animated beyond anything the guide had heard. His original estimate of these men as relatively quiet specimens underwent a sharp revision. Mitsuitei's report of the day's activity at his site had, it is true, been delivered quite calmly; but from then on matters grew progressively livelier. This was not caused by opposition to the archaeologist's plans. The other were all in favor of remaining, for their own reasons. However, the question of just what was likely to be found gave rise to much rather barbed comment on Sulewayo's part. "I don't see how you can expect to find any trace of civilized work here," he said flatly at one point. "The animal and plant life of this planet is at a stage of evolution corresponding to something like Earth's Pennsylvanian age, when the amphibians were the highest known forms of life. I'm not saying that there couldn't be such a thing as an intelligent amphibian. But I do say that the normal set of evolutionary forces which, on both Earth and Viridis, produced creatures of the amphibian pattern could have done that or produced an intelligent fish; not both. If the latter ever evolved, it failed; for the amphibians — pardon me,
amphibids — are here. To get an intelligent amphibid on this world will — or would, if the sun were to last long enough — require another orogenic period with the accompanying climatic changes. Then you'd stand a considerably higher chance of getting reptiles instead, if the comparative work done on over four hundred planets carries any meaning."
"I don't doubt the value of the work at all. You are very probably correct. It did not occur to me to expect remains of intelligent amphibians. I saw no reason to presuppose that anything in the way of artifacts which I might find would necessarily be native to this planet."
"You think there were, other visitors from outside the Beta Librae system?"
"The possibility certainly exists. Here we are."
"But for Pete's sake! Do you really expect that they stayed long enough to build a city; or do you think you have the remains of a camp like ours, or what?"
"I don't think anything. It has been suggested that such people did come, and stayed long enough to—"
"And you think you've found them."
"I think nothing, except, that I have found, with Rob's help, something which neither his professional knowledge, nor mine, nor even yours, is able to explain; and I think an explanation is desirable. I hope you won't consider me discourteous for pointing out that each time you have tried to accuse me of jumping to conclusions, you have been able to do so only by jumping to some yourself. I might further add that the suggestion that this planet had been stocked with its present supply of life types by visitors from space was advanced by a paleontologist, not by one of my colleagues. I gather he could not understand how life could evolve to the state it shows in the thirty-odd million years that the planet seems to have been solid. I neither support nor deride the idea; I simply want to gather data, in an attempt to explain a much simpler question why are narrow threads of copper compounds to be found every few feet in the volcanic tuff filling the joints in a certain limestone hill, and why are those threads always nearly horizontal? You and Hans say they are not organic fossils, and I accept your conclusion. Rob says that there is no copper in that rock, detectable with his equipment, except within a few millimeters of the green threads. I say nothing except that I have never seen such a thing before. Under the circumstances, I fail to understand where you get the idea that I think there is a city built by the people who stocked this world thirty million years ago buried under that hill. I know I said 'city' when I first saw it, and I still think I was justified in the opinion; I have now seen evidence which causes me to admit that the vegetation pattern was not caused by artificial structures, and I dismiss the original hypothesis. I still want to dig there, and in accordance with Rob's agreement I am going to dig there, with the assistance of anyone who chooses to help. I know you want to go back to your set of leg bones in the cliff, and have no objection to your doing so. Even I can now see, on the basis of your description, that you are uncovering the fossil of a land animal; and I agree that it is of great importance to get it out intact, if possible. But if I can see the importance and even the nature of your work, why can't you do the same for mine?" The little man was leaning forward and staring intensely into Sulewayo's face by the tin he finished this harangue, and Ndomi once more felt a trifle ashamed of himself. Lampert, however, saved him the need of formulating an apology.